Talk abstract list

ID 3

Title: Emulating Radiative Transfer

Author: J. Rino-Silvestre

Abstract: In the study of galaxies and active galactic nuclei (AGN) properties such as geometry, optical depth and kinematics were traditionally inferred from optical measurements. However this had its problems as dust grains in the interstellar medium (ISM) absorb and scatter photons. UV/optical photons absorbed by dust are then re-emitted in the infrared (IR). In the past decade there were relevant instrumentation advances in the FIR region which have enabled a significant improvement in the amount of IR data on both nearby and distant galaxies. Nevertheless radiative transfer modelling remains a critical tool in the study of the impact of dust attenuation and reddening on the observed structure and kinematics of galaxies and AGNs. It should also be noticed that the attenuation and reddening of light as it traverses the ISM lead to systematic uncertainties in the determination of cosmological distances. Monte Carlo Radiative Transfer (MCRT) models are obtained by simulating individual photons, from emission, through the multiple above mentioned processes as they traverse the medium to reach the observer, after which the global properties of the modeled object can be estimated. These models present however a major challenge since computational demand increases linearly with the desired information resolution for the model to be simulated. Here we perform an initial exploration, and propose the implementation, of two machine learning methods, namely dimensionality reduction and approximate Bayesian inference, to produce high information resolution-like models from low information resolution MCRT simulated models. We show that for a simple test case of a spherical dust shell, our approach is successfully emulating the target object. Indeed taking as input a version of that object with a hundredth of the simulated photons our reconstruction presents median residuals bellow 40% in both the spatial and spectral dimensions.

ID 4

Title: Robotics and machining for the METIS ELT/ESO instrument steering

Author: A. Amorim

Abstract: The METIS/ELT/ESO cryostat alignment system that is being developed by CENTRA fully demonstrates the application of the advanced machining and robotics concepts. Starting with the system design, the main architecture decisions are discussed, and the prototype development and validation is described while setting the context for the main tools of robotics, machining and metrology that are being used in the project. Past applications of these concepts in physics and astrophysics research are presented to help non-experts gasp the importance of these tools in scientific discovery.

ID 9

Title: Light pollution: the urgency of restoring the night in Portugal and the role of astronomers

Author: R. C. Lima

Abstract: Portugal achieved one unenviable position at the top of the European countries with the worst levels of light pollution per inhabitant and per GDP, and virtually without a single square centimetre of the continental territory without light pollution. A recent study on the emission of artificial light at night (ALAN) from the surface to the atmosphere (e.g. Falchi et al., 2019) revealed that Portugal uses luminous fluxes four times higher than Germany, the European country with the lowest emissions of ALAN to the atmosphere. Although there is today scientific consensus on the transversality of the impacts of ALAN, thus transcending Astronomy, it is also up to researchers and professionals in our areas to contribute to the solution. In addition to the proposal of intervention strategies of the scientific community of astronomers and astrophysicists as an interested party, the aim of this talk is to present the up-to-date situation of Portugal with regard to light pollution, the efforts that are being developed to mitigate the emission of ALAN in the country and to restore the night sky, and to summarise the achievements so far.

ID 10

Title: Better Science Through an Enhanced User Interface with the ALMA Archive

Author: A. Dias

Abstract: The Atacama Large Millimetre Array, located on the homonymous Chilean desert, constitutes one of the world’s most advanced interferometric observatories. Covering the millimetre and sub-millimeter wavelengths, the facility supports the needs of an ever-growing community within astronomy and astrophysics research groups. As it happens with all ground-based astronomical instruments, however, data storage and exploitation remains an outstanding challenge; while the former can be managed through technical upgrades to the Array instrumentation, the latter largely depends on how the archival data is accessed, analysed and presented to the user. Currently, ALMA observations are made publicly available through the ASA (ALMA Science Archive) online platform. Despite offering native, metadata-based filtering that can be applied to an observation’s various fields, such as location, spectral windows or integration time, it is understood that the ASA would benefit from supplementary tools improving its visualization components, allowing for a more direct assessment of both the archive’s global state and its more localized clusters (e.g. field density distribution). Therefore, this talk aims to describe the status of an ongoing project within the Institute of Astrophysics and Space Sciences (IA), foreseeing the development and production of a separate website that provides the user with a set of data analysis and visualization tools; while other functionalities are predicted to be included, the platform will mainly focus on the visual plotting of specific regions containing ALMA observations, enabling the users to directly identify particularly deep regions of the sky. Apart from allowing for a better scientific exploitation of pre-existing astronomical data through the combination of interrelated observations, the visualization toolkit may also increase the archive’s appeal and utility among non-expert users, promoting a larger public engagement with the ESO’s activities. Despite multiple ongoing projects with similar guidelines being developed, this system is the only one exclusively catered towards metadata-based data mining, with the potential to eventually support interaction with both secondary archives and complementary tools. On a long-term basis, it is intended that this platform will come to represent a valuable asset to the ALMA community - and, accordingly, was designed with scalability and incremental functionality implementation in mind.

ID 15

Title: Modified Gravity and Cosmology

Author: F. S. N. Lobo

Abstract: General Relativity and the ΛCDM framework are currently the standard lore and constitute the concordance paradigm. Nevertheless, long-standing open theoretical issues, as well as possible new observational ones arising from the explosive development of cosmology the last two decades, offer the motivation and lead a large amount of research to be devoted in constructing various extensions and modifications. We list the recent developments in the fields of gravity and cosmology, presenting the state of the art, high-lighting the open problems, and outlining the directions of future research.

ID 16

Title: Cosmological Density Field Emulation and Gravitational Wave Inference based on Dimensionality Reduction and Supervised Machine Learning

Author: M. Conceição

Abstract: Two major challenges in modern cosmology are the understanding of the origin and growth of cosmic structure and the progenitors of Gravitational Waves. Both scenarios require heavy computational resources to perform simulations and inference. In this work, we propose to adopt Machine Learning to alleviate these requirements, to enable significantly faster sampling and inference. We show that using Dimensionality Reduction and Supervised Learning, it is possible to generate high precision emulations of Dark Matter Density Fields given a set of cosmological parameters (the dark matter density and redshift). This led to orders of magnitude improvement in execution time and far less computational resources than running N-Body simulations. We also show that using the same approach it is possible to generate fast inferences of Chirp Masses from Binary Black Hole systems. The methods we present here may provide an important key to enabling fast and accurate data analysis for upcoming surveys like Euclid, LSST/Rubin, and LISA.

ID 21

Title: The impact of AGN on Galaxy Evolution

Author: T. Costa

Abstract: Our leading model of galaxy formation requires strong energy injection by active galactic nuclei (AGN), powered by accreting supermassive black holes, to account for the observed properties of massive galaxies. Even though such “AGN feedback” is widely accepted as a fundamental process in galaxy evolution, the detailed physical mechanisms through which it operates remain unidentified. In this talk, I will present results from numerical, (radiation-)hydrodynamic, cosmological simulations in which the effect of multiple AGN physical processes are systematically quantified and compared. Our cosmological simulations make a strong case against “momentum-driven” feedback, ruling out direct radiation pressure from AGN or accretion-disc wind-powered outflows suffering strong cooling losses as effective feedback channels. I will argue that radiation pressure arising from trapped infrared photons has a stronger impact on galactic nuclei, but too weak an effect in galaxy evolution as whole. While all these processes power significant galactic outflows, the associated energy is not sufficient to offset radiative cooling in massive galaxies. Instead, I will show that AGN feedback must be “energy-driven”, operating through extremely hot, over-pressurised bubbles capable of clearing galaxies and galactic haloes off copious gas masses. I will discuss the observational ramifications of energy-driven bubbles, including their impact on the properties of multi-phase outflows, the internal structure of massive galaxies and their ability to form stars.

ID 22

Title: Selection of obscured quasars with machine learning at high redshift

Author: P. Cunha

Abstract: Type II quasars (QSO2) are luminous active galactic nuclei (AGN) with a thick and dusty torus, oriented to hide the accretion disc from our line of sight (Antonucci 1993). The special orientation allows for a more detailed study of the effect of the AGN on the host galaxy. The growth and evolution of this type of object is crucial to understand the inner structures of galaxies and advance knowledge of the surrounding Universe. To identify QSO2 is a difficult task, due to their physical properties such as obscuration. We present a machine-transfer-learning based approach for the selection of Type II quasar (QSO2) candidates using the SDSS optical broadband magnitudes and WISE photometry. Our pipeline takes advantage of decision-trees, distance-based and deep learning methods to build a strong single classifier using a generalized stacking approach. The training data is comprised of QSO2 from SDSS BOSS at z>2, and ‘normal’ galaxies from SDSS. Testing the performance of our pipeline using cross-validation, we obtained high precision and recall, with an F1-score higher than 0.95. We have then applied the pipeline, in semi-supervised mode, to galaxies selected from SDSS, with the goal of identifying previously unknown QSO2 from the SDSS. We discuss the nature of the selected objects, including a population of [NeV]3426 emitters at z~ 1.1 .

ID 23

Title: Towards the detection of the earliest SMBHs

Author: S. Amarantidis

Abstract: One of the fundamental topics in extragalactic astronomy concerns the formation and evolution of galaxies through cosmic time. A common approach for shedding more light on this subject is the exploration of the young stages of the Universe, when the first stars and Super Massive Black Holes (SMBHs) were formed and therefore started ionising the intergalactic medium. This Epoch of Re-ionisation (EoR) is considered one of the key areas of extragalactic research that only recently we were able to explore, mostly due to the growing number of identified high-redshift Active Galactic Nuclei (AGNs). In this presentation, we will focus on the exploration of the EoR and the SMBH/AGN population, both from the theoretical and observational point of view. Regarding the former, we employ eight state-of-the-art cosmological galaxy formation and evolution models with the main goal of exploring their predictions regarding the number of AGNs that the current and next surveys would observe at the EoR. Furthermore, we combine one of these models with a software that simulates the observations from X-ray telescopes, generating a future possible survey using the next-generation telescope, Athena. Having these predictions in hand, the project advances by trying to identify high-redshift radio galaxies in deep and well-studied surveys. In this regard, we explore two selection criteria that are widely used and were successful in the past in detecting high-redshift galaxies, aiming to provide further evidence regarding their efficiency of studying the EoR.

ID 25

Title: Searching for Ha emission in the outskirts of galaxies with MUSE

Author: J. J. F. Calhau

Abstract: Gas accretion is, in conjunction with mergers, one of the primary ways through which galaxies grow and evolve. Numerical simulations predict that pristine gas accreted into galaxies is responsible for the formation and maintenance of disks and the sustaining of star formation - as well as other characteristics, such as the relations between stellar mass, SFR and metallicity. However, observational evidence of gas infall is difficult to obtain, particularly due to the low luminosity, large scale nature of the infalling gas. So far, emission has been detected at high redshift through the use of the Lya line, but a similar study may be possible to carry out using Ha at low redshift. Here we present the results of our attempt into extending the study of gas infall into the low redshift regime. We use the publicly available MUSE-WIDE data and target 178 low redshift (0.04 < z < 0.42) galaxies while searching for evidence of infalling gas. We use the Ha emission line to build ¨narrow band¨ Ha images and compare them with “broad band” images in the G, R and I band in order to identify structures related to gas kinematics in a large area in the outskirts of galaxies. Our results will contribute to the understanding of the relation between infalling gas and galaxy properties like metallicity and the modelling of gas and disk evolution in galaxies. The extension of the search for inflating gas to low redshift regime may also wield valuable insight about the evolution of the gas accretion rate across cosmic time.

ID 27

Title: Measurement of interstellar lines in supernova spectra and their relation to extinction

Author: S. Gonzalez-Gaitan

Abstract: The interstellar medium (ISM) has abundant gas atoms like sodium, potassium, calcium and molecules like the so called diffuse interstellar bands, among others, that can be observed in the spectra of astronomical sources whose light is absorbed in the ISM at the wavelengths of these species. The strength of these lines is known to correlate with the dust extinction in the line of sight, although several caveats exist like line saturation at high optical depths. We investigate here a large sample of supernova spectra and look for the narrow absorption lines of these elements from the ISM of the Milky Way. We develop a new automated technique to measure their equivalent widths and we compare those with the extinction values of Shlafly & Finkbeiner 2011. We find that sodium (Na I D) correlates best with extinction, and we find linear trends similar to previous findings. Furthermore, we apply a random forest regression to use all available lines and find a much better prediction of the extinction than using traditional single linear trends.

ID 29

Title: Y-NBS: HAWK-I in the recent Universe, exploring z < 2 line emitters

Author: H. Wade

Abstract: The star formation history of the Universe is fundamental to understand when studying the physics of galaxy evolution. Understanding this key property of the Universe requires the statistical study of large samples of galaxies through various redshifts. This also allows for the observation of extreme galaxies which are especially active and are undergoing a significant amount of star formation. Studying these rare sources will help uncover the physics of how emission lines are produced.

Narrowband surveys have done wonders for the observation of line emitting galaxies by providing a blind and unbiased selection. Large samples of Ha, [OIII] and [OII] emitters have been found in this way and recently the Ha, [OIII] and [OII] luminosity functions (LFs) have become well-constrained, but now is the time to constraint the faint and bright ends in a more consistent way: with deep, wide area surveys.

Therefore, I will present the first results from Y-NBS, a large narrowband survey (1.06 um) conducted with HAWK-I/VLT which finds ~2000 line emitters between z~0.6-1.8, in the GOODS-S and COSMOS field. We combine an area of ~1 deg^2 down to a Ha luminosity limit of 10^43.0 erg/s, providing wide and deep coverage in order to explore the full range of the luminosity functions for Ha, [OIII] and [OII] in a consistent way.

We select our fully-corrected samples of Ha (z~0.6), [OIII] (z~1.1) and [OII] (z~1.8) emitting galaxies and present results of luminosity functions, further constraining our knowledge of how line emitters evolve. We put these data in the context of the cosmic star formation rate density evolution, thereby adding to our understanding of the evolution of galaxies and the Universe as a whole and constraining current models of star formation history. These Ha, [OIII] and [OII] are also ideal for future study with the upcoming MOONS instrument.

ID 33

Title: Star formation history of galaxies in spectral synthesis methods

Author: C. Pappalardo

Abstract: The field of galaxy evolution will make a great leap forward in the next decade as a consequence of the huge effort done by the scientific community in multi-object spectroscopic facilities. To maximise the impact of such incoming data the analysis methods must also step up, extracting reliable information from the available spectra. In this talk, I investigate the limits and the reliability of different spectral synthesis methods in the estimation of the mean stellar age and metallicity. These two quantities are fundamental to determine the assembly history of a galaxy by providing key insights into its star formation history. The main question addressed are a) which signal-to-noise ratios (S/N) are needed to reliably determine these quantities and b) how this depends on the tool used to model the spectra. To address this question we built a set of realistic simulated spectra containing stellar and nebular emission and degraded them to different S/N. Then we analysed the results obtained with three spectral synthesis codes: FADO, STARLIGHT, and STECKMAP. Our results imply that when a galaxy has a high specific star formation rate (sSFR), the neglect of the nebular continuum emission in the fitting process has a strong impact on the estimation of its SFH, even with high S/N spectra. The median values of these differences are of the order of 7% (FADO), 20% (STARLIGHT), and 30% (STECKMAP) for light-weighted quantities, and 20% (FADO), 60% (STARLIGHT), and 20% (STECKMAP) for mass-weighted ones. Detailed investigations of the best-fit spectrum for galaxies with overestimated mass-weighted quantities point towards the inability of purely stellar models to fit the observed spectral energy distribution around the Balmer jump. Our work underlines once more the importance of a self-consistent treatment of nebular emission, which is the only viable route towards a determination of the assembly of any high-sSFR galaxy at high and low redshift.

ID 35

Title: FADO: a self-consistency tool for the investigation of galaxy evolution at low and intermediate redshift

Author: J. M. Gomes

Abstract: Despite significant progress over the past decades, all state-of-the-art population synthesis codes suffer from deficiencies limiting their potential of gaining sharp insights into the reconstruction of the star formation and chemical enrichment history of star-forming galaxies, i.e. the neglect of nebular continuum and the lack of a mechanism to ensure consistency between the best-fitting star-formation history and the observed nebular characteristics. These introduce biases in their recovered physical properties (stellar mass, mean stellar ages and metallicities, and specific star formation rates).

FADO is a novel self-consistent population synthesis code employing genetic optimisation. It is publicly available at http://www.spectralsynthesis.org. FADO can identify the star-formation & chemical enrichment histories that reproduce the observed nebular characteristics of galaxies, much-alleviating degeneracies in the spectral fits.

We present an adaptation of FADO to classify intermediate-redshift galaxies employing the concept of the “Blue Diagram” (e.g., Lamareille et al. 2010) for which the most prominent blue emission-lines (<~[OIII]5007) are observable while the Halpha (6563) and [NII] (6548,6583) are inaccessible.

We applied FADO to realistic simulated spectra from the new infrared instrument VLT/MOONS - constructed mock synthetic spectra at higher-redshifts with different star-formation histories recipes. As a result, FADO can recover galaxies’ physical and evolutionary properties, such as stellar mass and mean stellar age/metallicity, with an accuracy significantly better (~ 0.2 dex) than purely stellar codes.

We will present an outline of FADO and applications to local and intermediate-redshift galaxies.

ID 37

Title: Athena X-ray Mission: A sharper view of the Hot and Energetic Universe

Author: I. Matute

Abstract: Two of the most intriguing questions in modern astrophysics are: How do baryons assemble and form the large-scale structures in the Universe that we see today? And how do black holes grow and influence their surrounding Universe? Given the physical conditions present in systems that closely map the aforementioned questions, like the intracluster medium in clusters of galaxies or the gas close to the accretion disk in AGN, an order of magnitude increase in sensitivity and survey speed is required for telescopes observing the “Hot and Energetic Universe” to significantly push our knowledge boundaries. Athena, the Advanced Telescope for High Energy Astrophysics, is the next-generation X-ray observatory selected as the second large mission (L2) of ESA’s Cosmic Vision-programme and scheduled to launch in 2031. Athena will address the “The Hot and Energetic Universe” science theme with its two main science instruments: the Wide Field Imager (WFI) and the X-ray Integral Field Unit (X-IFU). This talk will provide an overall Athena overview and briefly discuss the main scientific cases aimed by the Athena instruments (WFI & X-IFU) and the potential for the Portuguese researchers in the fields of cosmology, galaxy evolution, as well as galactic and stellar studies. Within this context, I will briefly describe the participation of the IA extragalactic team in the WFI instrument consortium, the ongoing involvement in its scientific and technical development, the connection to the broader search of the earliest black holes, and the synergies with future observatories specially tuned to trace accretion activity along cosmic time (e.g. SKA pathfinders and SKA itself).

ID 39

Title: Exploration of Dark Matter Profiles in Ultra-Faint Dwarfs

Author: M. P. Júlio

Abstract: The requirement for non-baryonic dark matter to explain the large-scale structure of the universe is supported by various lines of evidence, yet understanding its nature remains one of the most outstanding questions in Astrophysics. One particularly promising way to pursue this is to study the so-called core-cusp problem. If the dark matter is cold, simulations generically predict a steep power-law like behaviour (cusp) in the dark matter density profile, but intriguingly the observations of dwarf galaxies suggest an approximately constant dark matter density in the inner parts of galaxies (core). \par Many solutions have been investigated to solve this problem - one possibility is that the nature of the dark matter itself is different from what we thought. To reduce the impact of baryonic physics which obscures our ability to constrain dark matter, we need to study the most dark matter dominated systems known, ultra-faint dwarfs. Here we present the first spectroscopic observations of the Antlia, a distant (d ∼ 1.35 Mpc) ultra-faint dwarf ($M_V = -9.4$, M$\star ∼ 8\times 10^5$M$\odot$ ), from MUSE-Faint – a survey of ultra-faint dwarfs with the Multi Unit Spectroscopic Explorer. We measure line-of-sight velocities of 127 member stars, and combine these with GravSphere, a Jeans modelling code, to place constraints on dark matter and derive the first dark matter density profile for this object. \par In particular we present constraints on the nature of self-interacting dark matter (SIDM) that is based on the assumption that the dark matter particles can scatter with one another, being able to transport heat through the dark matter halo, altering the halo structure – and, possibly, producing a constant-density core in the heart of the halo; and scalar field dark matter (SFDM) that is a Bose-Einstein condensate and a quantum superfluid and can suppress structure formation when there is a strong repulsive self-interaction. These are to our knowledge the first constraints on SFDM using ultra-faint dwarf galaxies and we show that we can rule out SFDM as an explanation for the cores in the larger dwarf galaxies in the Local Group. We also show that if Antlia B has a core produced by SFDM, the characteristic length scale of the repulsive self-interaction has to be smaller than $R_{\text{TF}} \approx 0.37$ kpc.

ID 43

Title: From Gravity to Gravity+, the Nobel, and on there and back again

Author: P. J. V. Garcia

Abstract: We will present the recent efforts on the hunting and gathering of knowledge on the galactic centre supermassive black hole close environment. Since our last talk, the 2020 Nobel Prize in Physics was awarded in part to the detection of relativistic effects by the galactic centre supermassive black hole on stellar probes. We will revisit the Nobel and the significance of the detection of Schwarzschild precession. We will then report on our efforts towards black hole spin detection, that rely on discovering stars with closer orbits. We will also discuss how the flares observed in the galactic centre emission can constrain new physics for the central compact object. Finally, we shortly report on the Phase A review of the Gravity+ instrument which will open up the extragalactic sky for milliarcsecond-resolution interferometric imaging, and give access to targets as faint as K = 22 mag.

ID 45

Title: Final Results of Doppler Velocimetry Winds on Mars’ Atmosphere

Author: P. Machado

Abstract: In 2018 a regional dust storm on Mars has evolved to a global scope, becoming one of the largest dust storms ever observed. These rare and unpredictable events are poorly known. A key factor for its evolution is the role played by the Martian winds. Measuring winds on Mars is a real challenge for remote observations but a global dust storm offers to us a unique opportunity thanks to an innovative technique to measure the Doppler effect of solar Fraunhofer lines back-scattered on the Mars dust cloud. A high spectral resolution is required to resolve the solar lines and to allow us to measure with precision the line shifts due to aerosol motion and in this manner retrieve the related wind map. We used dedicated ground-based observations made with the Ultraviolet and Visual Echelle Spectrograph (UVES) at the European Southern Observatory’s Very Large Telescope (VLT) facility in Chile. This instrument’s high resolution (R ~100000) allows for the dust cloud velocity to be measured, by computing the Doppler shift induced in the Fraunhofer lines (λ of 420-1100 nm) in the solar radiation that is back-scattered in the dust suspended in the Martian atmosphere, by the motion of that same dust particles, with an average error of approximately 5 ms-1. The processes that allow for the development of global dust storms are poorly understood. Furthermore, the cut-off mechanisms that spur the end of these storms are also without consensus and may even vary from storm to storm. During such events dust can be lifted to heights above 50 km across all latitudes and longitudes, increasing the optical depth along the dust layer in atmospheric suspension and increasing the heat absorbed at each altitude covered by dust [1,2]. Global dust storms are complex stochastic events that can drastically alter the atmospheric dynamics [3,4]. These storms usually develop in the southern hemisphere during southern Summer and Spring ( Ls ≈ 180º - 360º), however, the 2018 storm started developing in the northern hemisphere on Ls ≈ 185º. Our understanding of both the initiation and decline of global dust storms is only marginal, nevertheless we do know that such events probably originate from the superimposition of three circulation components: the Hadley cell, thermal tides and topographically controlled circulations. This mechanism was suggested by Leovy (1973) [5] and relies on the seasonally increased insolation and dust loading coupled with the above-mentioned components to allow certain storms to become global at the planetary scale. The decay of dust storms is even more obscure as the cause for the halting of the dust lifting hasn’t been unambiguously identified. Either the depletion of surface dust available for lifting shuts off the lifting events (which requires replenishment of the surface dust sources) or the decrease in intensity of the various components allows for the surface wind stress to drop below the required threshold for dust lifting [6,7]. Mars’ atmosphere is highly transparent in the visible and ultraviolet ranges and the back-scattered radiation in those wavelength ranges in the atmosphere is negligible which precludes the application of the Doppler velocimetry method that we developed and fine-tuned for the case of Venus [8,9,10,11,12]. However, during global dust storms, the opacity of the atmosphere increases and allows for the scattering of enough light in the suspended dust in the middle atmosphere for the application of our Doppler method in an effective way. The adaptation of our Doppler velocimetry method took in account the geometry of our observations. Spherical geometry was used to locate the observations within the planet, as seen from Earth at the time of each observation, and to compute the de-projection of the radial Doppler velocities from the observer’s line-of-sight, for each point of the slit and for each exposure. The rotation velocity’s contribution to the overall Doppler shift was removed by computing and subtracting the rotation velocity at each point on Mars sensed by the spectroscopic slit. Furthermore, the contributions made to the total shift by the Young effect were evaluated and deemed negligible under the specific geometry of our observations. The scope of this work is to study the dynamical behaviour of Mars’ middle atmosphere during a global dust storm using ground-based observations made with the high-resolution spectrograph UVES at ESO’s Very Large Telescope and Doppler velocimetry methods, for the first time, to complement observations of orbiter instruments. The success and validation of the application of this method to the atmosphere of Mars may provide a new tool to investigate the Martian atmosphere during dust storms. We intent is to contribute for a better understanding of the atmosphere’s dynamics during planet encircling dust events. We measured the wind velocity and its spatial variability, through high resolution spectroscopy and Doppler velocimetry. The main goal of this research line is therefore, to provide wind measurements using visible Fraunhofer lines scattered at Mars’ dust hazes, which allows spatial wind variability studies and will make possible to obtain a latitudinal profile of the wind along the cited global dust storm and a wind map of the dust storm as a function of the latitude and local time over the planet as seen from Earth. Acknowledgements: We acknowledge support from the Portuguese Fundação Para a Ciência e a Tecnologia ref. PTDC/FIS-AST/29942/2017 References: [1] Vandaele, et al., Nature, 568, 2019. [2] Stone, S., et al. Science, Vol. 370, 2020. [3] Zurek, R., and Martin, L., JGR, 98, 1993. [4] Haberle, R.M., Science, 234, 1986. [5] Leovy, C. Journal of Atmospheric Sciences, 30, 1973. [6] Kahre, M., et al., Cambridge University Press, 2017. [7] Pollack, J., JGR, 1979. [8] Machado, P., et al., Icarus, 2012. [9] Machado, et al. Icarus, 285, 2014. [10] Machado, et al. Icarus, 2017. [11] Machado P., et al., Atmosphere, 2021. [12] Gonçalves R., et al., Icarus, vol 335, 2020.

ID 46

Title: Characterising Atmospheric Gravity Waves on Mars using Mars Express OMEGA images – a preliminary study

Author: F. Brasil

Abstract: We report preliminary result of the systematic detection and characterisation of atmospheric gravity waves on Mars’ atmosphere, using observations carried out by the OMEGA (Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité) [1] imaging spectrometer on board of the Mars Express (MEx) [2]. Gravity waves are mesoscale atmospheric oscillations in which buoyance acts as the restoring force [3]. The presence of gravity waves is observed in many of the Solar System planets atmospheres, from Venus [4], Earth [5], Jupiter [6], and being a crucial factor in the circulation of planetary atmospheres since they transport momentum and energy, which can dissipate at different altitudes and force the dynamics of several layers of the atmosphere. The source of these waves can be associated with the topographic features (orographic gravity waves) of surface, or with jet streams and atmospheric convections (non-orographic gravity waves). Recent modelling studies showed the strong role of gravity waves on diurnal tides on Mars atmosphere [7], however their characteristics are still not well constrained by observations. This work aims to go through the complete OMEGA data set to fully detect and characterise gravity waves observed during the Mars Express space probe. Every image was navigated and processed in order to optimise the detection of the wave packets and accurate characterisation of the wave properties such as the horizontal wavelength, packet width, packet length and orientation. Due to the longevity of the MEx space mission, acquiring over more than 17 years of observations of the surface and atmosphere of Mars in nadir and limb modes, the OMEGA instrument offers an opportunity to explore the atmosphere dynamics over the years, especially the evolution of gravity waves along the time, due to the time sampling and global coverage of MEx. The OMEGA images are composed of a hyperspectral cube with a spectral range of 0.38 to 5.1 μm, taken with the visible and near-infrared (VNIR) and infrared (SWIR) spectrometers. We retrieved the OMEGA data and its IDL routines through the PSA archive from ESA, to produce OMEGA images which were later navigated and processed individually using ENVI software for optimal detection of wave features and accurate characterisation of wave properties, such as the horizontal wavelengths, packet width, packet length, location and orientation. Since the orbit has a certain resonance with respect to the Martian surface rotation (variable duration along the mission), there will be an overlapping of images taken, allowing the study of the evolution of gravity waves along a period of time and also the study of their activity during dust storms [8].

Acknowledgments: This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UIDB/04434/2020, UIDP/04434/ 2020, P-TUGA PTDC/FIS-AST/29942/2017.

References

[1] Bibring, J. P., et al. OMEGA: Observatoire pour la Minéralogie, l’Eau, les Glaces et l’Activité. In: Mars Express: the scientific payload. 2004. p. 37-49.

[2] Chicarro, A.; Martin, P.; Trautner, R. The Mars Express mission: an overview. In: Mars Express: The Scientific Payload. 2004. p. 3-13.

[3] Fritts, D. C.; Alexander, M. J. Gravity wave dynamics and effects in the middle atmosphere. Reviews of geophysics, 2003, 41.1.

[4] Silva, J. E., et al. Characterising atmospheric gravity waves on the nightside lower clouds of Venus: a systematic analysis. Astronomy & Astrophysics, 2021, Volume 649.

[5] Hines, C. O. Gravity waves in the atmosphere. Nature, 1972, 239.5367: 73-78.

[6] Young, A. et al. Gravity waves in Jupiter’s stratosphere, as measured by the Galileo ASI experiment, Icarus, 2005, Vol 173, p. 185-199.

[7] Gilli, G., et al. Impact of gravity waves on the middle atmosphere of Mars: A non‐orographic gravity wave parameterization based on global climate modeling and MCS observations. Journal of Geophysical Research: Planets, 2020, 125.3: e2018JE005873.

[8] Gondet, B.; Bibring, J. P. Mars observations by OMEGA/Mex during the dust events from 2004 to 2019. In: EPSC-DPS Joint Meeting 2019. 2019. p. EPSC-DPS2019-94.

ID 47

Title: Final Results on Nightside small scale Waves on Venus

Author: J. E. O. Silva

Abstract: An atmospheric internal gravity wave is an oscillatory disturbance on an atmospheric layer in which buoyancy acts as the restoring force. As such, they can only exist in a continuously stably stratified atmosphere, that is, a fluid in which the static stability is positive and horizontal variations in pressure are negligible when compared to the vertical variations (in altitude) [Gilli et al. 2020; Peralta et al. 2008]. These waves are of particular interest because they represent an effective means of energy and momentum transport across various layers of a planetary atmosphere, as these waves can form on one atmospheric region and travel through the atmosphere, sometimes over great distances, and dump their contained energy upon wave dissipation or breaking [Alexander et al. 2010]. Given these properties, study of atmospheric waves on Venus becomes important as another tool to answer some of the fundamental question surrounding its atmosphere dynamics, mainly the origin and support mechanism of the remarkable superrotation of the atmosphere. We present here the final results on a study conducted on the nightside lower cloud of Venus to detect and characterise mesoscale waves. This analysis was conducted with infrared imaging data from both the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) onboard Venus Express (Vex) [Svedhem et al. 2007] and the 2-micron camera (IR2) onboard Akatsuki [Nakamura et al. 2011, Satoh et al. 2016] space missions. We covered the entire VIRTIS-M-IR archive selecting the 1.74- and 2.25-micron wavelengths as well as all available images from the IR2 camera at 2.26 microns to ensure a most comprehensive survey and through image navigation and processing we were able to characterise approximately 300 wave packets across more than 5500 images over a broad range of latitudes on Venus. From these waves we retrieved basic morphological properties such as horizontal wavelength, number of crests and the full extent of the wave. Additionally, we were able to track the evolution of waves as they moved on the atmosphere, enabling some dynamical characterisation. Our goal was to provide an observational study on atmospheric waves in the lower cloud as complete as possible, using two different instruments which cover in detail different sections of the globe of Venus over a long-time span, expanding on other studies performed by Peralta et al. (2008), (2019). With the larger data base, we discuss the nature of these waves, possible forcing mechanisms, and their relationship with the background atmosphere. Several questions remain however, such as how much energy do these waves transport in the cloud layer and how much do they contribute to Venus’ superrotation and if there is a dominant source of excitation for these waves. Full details of these results can be found in Silva et al. (2021) and we hope that these updated results can prove useful to recent and future models of Venus atmosphere as well as atmosphere of other slow rotators in the Solar System.

References • Alexander M.J. et al, Quarterly Journal of the Royal Meteorological Society, vol. 136, pp. 1103-1124, 2010; • Gilli G. et al, Journal of Geophys. Research – Planets, ID. e05873, 2020; • Nakamura M. et al, Earth, Planets and Space, vol. 63, pp. 443-457, 2011; • Peralta J. et al, Journal of Geophysical Research, vol. 113, ID. E00B18, 2008; • Peralta J. et al, Icarus, vol. 333, pp. 177-182, 2019; • Satoh T. et al, Earth, Planets and Space, vol. 68, ID. 74, 2016; • Silva J. et al, A&A, vol. 649, ID. A34, 2021; • Svedhem H. et al, Planetary and Space Science, vol. 55, pp. 1636-1652, 2007;

ID 48

Title: Venus Dynamics on the framework of Bepicolombo flyby to Venus and Akatsuki UVI coordinated observations with TNG HARPS-N observations

Author: D. C. Espadinha

Abstract: Introduction

One of the most crucial bases and tools in planetary sciences is the general circulation model of a planet’s atmosphere. These models come as a result of the analysis of great amounts of observations, in order to accurately describe the atmospheric circulation of a planet. For Venus, the better understanding of cloud circulation can yield important results such as the possibility to explain and describe one of its most fascinating characteristics: the superrotation of Venus’ atmosphere.

Methods and Tools

The cloud-tracking method consists of an analysis of a pair of navigated and processed images, provided that we know the time interval between both. It is possible to probe the motion of cloud features between the initial and second image, either by matching specific points or areas in both images. This matching process allows us to measure displacements and velocities of cloud features and deduct the average velocity for a certain cloud layer of the atmosphere, selected in the wavelength range of the observations (Peralta et al. 2018). The use of an evolved tool of cloud tracking based on phase correlation between images and other softwares (Hueso et al. 2010) allows to explore Venus’ atmospheric dynamics based on coordinated space and ground observations including Akatsuki UVI instrument, TNG/HARPS-N, and data from BepiColombo’s first Venus’ flyby. Images used were navigated and processed for optimal identification of cloud features which help with the matching processes described above. The main goal of this work was to build wind profiles in different wavelengths which allow us to analyse several layers of the Venusian atmosphere. We present some results of this study following the works of Sánchez-Lavega et al. 2008, Hueso et al. 2013 and Horinouchi et al. 2018 and compare them with ground-based Doppler measurements (Machado et al. 2021). The Doppler velocimetry method mentioned in this work was initially developed by Thomas Widemann (Widemann et al., 2008) and further evolved by Pedro Machado for both long slit and fibre-fed spectrographs, using UVES/VLT and ESPaDOnS/CFHT respectively (Machado et al., 2012, 2014). This technique is based on solar light scattered on Venus’ dayside to provide instantaneous wind velocities measurements of its atmosphere. The sunlight is absorbed by cloud particles in Venus’ top clouds and then re-emitted in Earth’s direction in a single back-scatter approximation (Machado et al., 2012, 2014, 2017).
Another goal of this study is connected to the detection and characterisation of atmospheric gravity waves. These waves are oscillatory disturbances on an atmospheric layer in which buoyancy acts as the restoring force. They can only exist in stably stratified atmospheres, that is, a fluid in which density varies mostly vertically (Silva et al. 2021).

Results

With this work we present new results of studies of zonal and meridional winds in both Venus’ hemispheres, using ground- and space-based coordinated observations. The wind velocities retrieved from space used an improved cloud-tracked technique and the results obtained from telescope observations were retrieved with a Doppler velocimetry method, both already described in “Methods and Tools”. There is evidence that the altitude level sensed by the Doppler velocimetry method is approximately four kilometres higher than that using ground-tracked winds which is shown by models which predict wind profiles developed at the Laboratoire de Meteorologie Dynamique (Machado et al. 2021).

References

[1] Hueso et al., The Planetary Laboratory for Image Analysis (PLIA). Advances in Space Research, 46(9):1120–1138, 2010.
[2] Sánchez-Lavega et al., Variable winds on Venus mapped in three dimensions. Geophysical Research Letters, 35 (13), 2008 [3] Hueso et al., Venus winds from ultraviolet, visible and near infrared images from the VIRTIS instrument on Venus Express. 2013. [4] Horinouchi et al., Mean winds at the cloud top of venus obtained from two-wavelength UV imaging by Akatsuki. Earth, Planets and Space, 70:10, 2018. [7] Machado et al., Characterizing the atmospheric dynamics of Venus from ground-based Doppler velocimetry, Icarus, Volume 221, p.248-261, 2012. [6] Machado et al., Wind circulation regimes at Venus’ cloud tops: Ground-based Doppler velocimetry using CFHT/ESPaDOnS and comparison with simultaneous cloud tracking measurements using VEx/VIRTIS in February 2011, Icarus, 2014. [7] Machado et al., Venus Atmospheric Dynamics at Two Altitudes: Akatsuki and Venus Express Cloud Tracking, Ground-Based Doppler Observations and Comparison with Modelling. Atmosphere 2021, 12, 506. [8] Machadoet al., Venus cloud-tracked and Doppler velocimetry winds from CFHT/ESPaDOnS and Venus Express/VIRTIS in April 2014. Icarus, vol. 285, p. 8-26, 2017. [9] Peralta et al., Nightside Winds at the Lower Clouds of Venus with Akatsuki/IR2: Longitudinal, Local Time, and Decadal Variations from Comparison with Previous Measurements. The American Astronomical Society. The Astrophysical Journal Supplement Series, Volume 239, Number 2, 2018 [10] Widemann et al., Venus Doppler winds at cloud tops observed with ESPaDOnS at CFHT, Planetary and Space Science, Volume 56, p. 1320-1334, 2008. [11] Silva et al., Characterising atmospheric gravity waves on the nightside lower clouds of Venus: a systematic analysis, A&A 649 A34, 2021.

Acknowledgements We thank the JAXA’s Akatsuki team for support with coordinated observations. We gratefully acknowledge the collaboration of the TNG staff at La Palma (Canary Islands, Spain) - the observations were made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. We acknowledge support from the Portuguese Fundação Para a Ciência e a Tecnologia (ref. PTDC/FIS-AST/29942/2017) through national funds and by FEDER through COMPETE 2020 (ref. POCI-01-0145 FEDER-007672) and through a grant of reference 2020.06389.BD.

ID 50

Title: Planetary parameters impact in the large-scale atmospheric circulation of Venus-like exoplanets and observational prospects

Author: D. Quirino

Abstract: The prospective detection of rocky exoplanets in short-period orbits in nearby M-dwarf stars is a likely result of present and future observational campaigns. These exoplanets represent the best Earth-size targets for future atmospheric characterisation studies. Similarly, the atmosphere of our neighbouring planet Venus provides a natural laboratory to make a first step to address the expected climate diversity of this possible exoplanet population [1], i.e., rocky highly irradiated exoplanets. In this work, we propose to use a 3D Global Climate Model (GCM), the LMD-Generic GCM, now widely used for exoplanets and paleoclimate studies [2, 3], for atmospheric studies of the Venus-like exoplanet population orbiting M-dwarf stars. The objectives are two-fold: (1) to study the response of the large-scale atmospheric circulation to varying specific planetary parameters – e.g., radius, gravity - selected according to specific mass-radius relationships [4], surface atmospheric pressure and solid-body rotation rate; and (2) to produce synthetic observables: emission and reflection phase curves [5], to support the characterisation of this exoplanet population in the future. To assess the impact from simulating a hot, dense atmosphere, we have run the 3D GCM using the planetary parameters of TRAPPIST-1 c as a framework reference for a possible Venus-like exoplanet. We assumed synchronous rotation, no eccentricity and zero obliquity, and a Venus-like atmosphere, with a 92-bar surface atmospheric pressure, with similar chemical composition and cloud structure [6]. A large-scale atmospheric characterisation is provided in terms of temperature and dynamical parameters for different pressure levels, particularly at and above the classical pressure level for Venus’s top cloud deck. Outgoing top-of-the-atmosphere radiative fluxes computed by the model are used to produce emission and reflection phase curves and interpret possible variations from atmospheric dynamics, e.g., superrotation and jets.

Keywords: Venus-like exoplanetary atmospheres, GCM, large-scale atmospheric circulation, phase curves.

References: [1] Kane et al. 2019. JGR. 124. [2] Wordsworth et al. 2011. ApJL. 733. L48. [3] Forget & Leconte. 2014. Phil. Trans. R. Soc. A372. [4] Zeng et al. 2016. ApJ. 819. 127. [5] Turbet et al. 2016. A&A. 596. A112 [6] Garate-López & Lebonnois. 2018. Icarus. 314.

ID 52

Title: Measure the spin-up of hot-Jupiters due to tides

Author: N. M. P. C. Rosário

Abstract: Tidal interaction between a star and a close-in exoplanet leads to shrinkage of the planetary orbit and eventual tidal disruption of the planet. For some of the known exoplanets the expected orbital period variation due to tides is observable over 10 years and they are expected to have measurable tidal decay by now. We analyze TESS data for two targets known to host close-in hot Jupiters: WASP-18 and WASP-4. We aim to measure the current limits on tidal decay which will provide new constrains on the modified tidal quality factor Q’. We fit the transit parameters for each target using TESS data from all observed sectors by the date of this report and use the updated parameters to fit the mid-transit times of each individual transit. We use previously published timings with our results to find the change in period with a quadratic ephemerides model and verify the presence of orbital decay. We obtain new minimum values for Q’ for hot-Jupiters expected to show orbital decay and improve the precision on the known planet parameters for our targets with new observations from TESS. We observe a clear period change in WASP-4b and an indication of decreasing period in WASP-18b but we still do not have enough precision to constrain Q’* significantly on the latter.

ID 55

Title: Detection and limits of detection of minor chemical species in Solar System’s atmospheres

Author: J. A. Dias.

Abstract: The study of minor chemical species in terrestrial planets atmospheres can teach us about the chemistry, dynamics and evolution of the atmospheres through time [1]. The detection of phosphine or methane on terrestrial planets is a possible biosignature, such that it can pinpoint the presence of life on a planet, if detected in chemical disequilibrium amounts [2,3]. The search done to look for these compounds in the Solar System will inform future studies on exoplanets.

Encrenaz et al [4], through observations in the infrared using TEXES, at 951-956 cm-1 (10.46 µm-10.52 µm), did not detect phosphine absorption lines, but instead proposed an upper limit of 5 ppb. This amount of phosphine is not explained by models. Moreover, phosphine is detected in chemical disequilibrium amounts in Jupiter’s upper atmosphere. However, this can be explained by upwelling of phosphine from the deepest layers of the atmosphere, where it is produced by equilibrium chemistry [5].

Giuranna et al [6] reported the historic detection of methane on Mars at around 3018 cm-1 (~3.31 µm), corresponding to an estimated abundance around 15.5 ppb, using the Planetary Fourier Spectrometer (PFS), onboard Mars Express. The NOMAD/ACS instruments onboard the ExoMars mission also attempted to detect methane lines for a broad range of latitudes and longitudes, at around 3029 cm-1 (~3.30 µm) and 3048 cm-1 (~3.28 µm) [7], but the search was not successful.

Using the Planetary Spectrum Generator [8], an online radiative transfer suite, our group has been performing simulations of planetary spectra with the goal of identifying methane on Mars and phosphine on Venus by reanalyzing IR observations by Guiranna et al [6] and Encrenaz et al [4], respectively. Also, data from the Infrared Space Observatory (ISO) [9] has been reanalyzed to search for methane and phosphine features in the infrared, around 7-12 µm, on Jupiter and Saturn.

Some results of our work include the positive detection of SO2 and the negative detection of PH3, on Venus, and a positive detection of CH4 on Mars. In the simulation of the ExoMars NOMAD data [7], methane lines appear on the simulation despite not appearing in the data.

After the detection was done, using both a chemical retrieval module included in PSG, based on the Optimal Estimation Method by [10], and a line depth ratio method [4], some abundances were estimated. On Venus, our work estimates an abundance of SO2 of 18-192 ppb (z~60-80 km) in agreement with a value of 50-100 ppb by Encrenaz et al [4]. On Jupiter, our work estimates the abundances of CH4 and PH3 to be 1.8x10^(-3) and 5.7-6.6x10^(-7) (above and bellow the tropopause, respectively), comparable with 2.1-5.6x10^(-3) [11] and 10^(-7)–10^(-6) [9].

In sum, PSG proved to be an effective tool when looking for signatures of minor chemical species in planetary atmospheres and for compounds with astrobiological interest. Future prospects include constraining an upper limit of PH3 on Venus and the abundance of CH4 on Mars as well as determining the D/H ratio of these planets by comparison with observations by Fedorova et al [12] and Encrenaz et al [13].

Aknowledgements: We thank Dr. Marco Guiranna, PI of the Mars Express PFS instrument, and Dr.Thérèse Encrenaz, from LESIA, for sharing with our group data from Guiranna et al [9] and Encrenaz et al [7], respectively. We acknowledge support from the Portuguese Fundação para a Ciência e a Tecnologia ref. PTDC/FIS-AST/29942/2017

References

[1] T. Encrenaz. High-resolution imaging spectroscopy of planetary atmospheres. Comptes Rendus Geoscience, 2015.

[2] Schwieterman, E., Kiang, N., Parenteau, M., Harman, C., DasSarma, S., Fisher, T., Arney, G., Hartnett, H., Reinhard, C., Olson, S., Meadows, V., Cockell, C., Walker, S., Grenfell, J., Hegde, S., Rugheimer, S., Hu, R. and Lyons, T., 2018. Exoplanet Biosignatures: A Review of Remotely Detectable Signs of Life. Astrobiology.

[3] Sousa-Silva, C., Seager, S., Ranjan, S., Petkowski, J., Zhan, Z., Hu, R. and Bains, W., 2020. Phosphine as a Biosignature Gas in Exoplanet Atmospheres. Astrobiology.

[4] Encrenaz, T., Greathouse, T., Marcq, E., Widemann, T., Bézard, B., Fouchet, T., Giles, R., Sagawa, H., Greaves, J. and Sousa-Silva, C., 2020. A stringent upper limit of the PH3 abundance at the cloud top of Venus. Astronomy & Astrophysics.

[5] Irwin, P., 2006. Giant planets of our solar system. Berlin: Springer.

[6] Giuranna, M., Viscardy, S., Daerden, F., Neary, L., Etiope, G., Oehler, D., Formisano, V., Aronica, A., Wolkenberg, P., Aoki, S., Cardesín-Moinelo, A., Marín-Yaseli de la Parra, J., Merritt, D. and Amoroso, M., 2019. Independent confirmation of a methane spike on Mars and a source region east of Gale Crater. Nature Geoscience.

[7] Korablev, O., Vandaele, A.C., Montmessin, F. et al. No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations. Nature, 2019.

[8] Villanueva, G. L., Smith, M. D., Protopapa, S., Faggi, S., Mandell, A. M., Planetary Spectrum Generator: an accurate online radiative transfer suite for atmospheres, comets, small bodies and exoplanets, Journal of Quantitative Spectroscopy and Radiative Transfer, 2018.

[9] Encrenaz, T., Drossart, P., Feuchtgruber, H., Lellouch, E., Bézard, B., Fouchet, T. and Atreya, S., 1999. The atmospheric composition and structure of Jupiter and Saturn from ISO observations: a preliminary review. Planetary and Space Science.

[10] C. D. Rodgers. Inverse methods for atmospheric sounding: theory and practice. World Scientific, 2008

[11] Lellouch, E., et al. “The Deuterium Abundance in Jupiter and Saturn from ISO-SWS Observations.” Astronomy & Astrophysics, vol. 370, no. 2, 2001, pp. 610–622.,

[12] Fedorova, A., Korablev, O., Vandaele, A., Bertaux, J., Belyaev, D., Mahieux, A., Neefs, E., Wilquet, W., Drummond, R., Montmessin, F. and Villard, E., 2008. HDO and H2O vertical distributions and isotopic ratio in the Venus mesosphere by Solar Occultation at Infrared spectrometer on board Venus Express. Journal of Geophysical Research

[13] Encrenaz, T., DeWitt, C., Richter, M., Greathouse, T., Fouchet, T., Montmessin, F., Lefèvre, F., Bézard, B., Atreya, S., Aoki, S. and Sagawa, H., 2018. New measurements of D/H on Mars using EXES aboard SOFIA. Astronomy & Astrophysics, 612, p.A112.

ID 58

Title: Fighting Stereotypes with Astronomy Education

Author: R. Doran

Abstract: During my talk I would like to share with the audience recent efforts from our institution to include the component of inclusion and stereotypes prevention in our professional development courses. For 2 consecutive years over 500 educators, at a national and international level, had the opportunity to engage in professional development opportunities, online, related to astronomy and space exploration. Alongside current trends in astronomy and space exploration, shared by experts in the field, they had also the opportunity to experiment the various topics with hands-on activities, discussion and reflection sections on how to bring real research to the hands of students and how to avoid stereotypes. The component of inclusion was also a strong part of the courses. The toolkit of activities were prepared in the framework of European projects and shared during national and internacional courses. Our team also engaged in researchers’ training opportunities related to science communication and preparing scientists to work with educators. During the talk a series of best practices from researchers working with schools will also be presented.

ID 59

Title: Astronomy fade out in portuguese compulsory schooling: a crossroads for astronomy national stakeholders

Author: I. A. Costa

Abstract: Since 2009, in Portugal, school attendance has been compulsory between the ages of 6 and 18 years old (1st to 12th grade). Within this compulsory schooling framework, education is universal and free of charge, which is a key aspect for democratising access to science. For children and teenagers this may well be the only opportunity to be engaged with astronomy: awareness is a precondition of interest and enjoyment with this science. That is more relevant since the literature reveals that astronomy interest is shaped at an early age. Within this context, the presence of astronomy content and processes in the portuguese national curriculum becomes very important, not only for astronomy education itself, but also for the future of astronomy research in the country. In this work we present a qualitative study that: by content analysis, looked at the portuguese curricular documents; with a case study, analysed some practices of an astronomy science center, the Porto Planetarium - Ciência Viva Center (PP-CCV). The results show that over the past few years, as new curriculum documents have come into force, astronomy subjects have been gradually disappearing. In the latest major curriculum changes, named “Aprendizagens essenciais” [essential learnings], astronomy content is explicit in only a few school years, in a fewer number of school subjects and with a sporadic and superficial approach, of limited astronomy themes, some of which considered by research as less relevant. The only exception is the theme “Solar System & Universe” in the 7th grade. This becomes more dramatic by realising that those “Aprendizagens essenciais” are the national benchmarks for external assessment, the national exames, implying that essential learnings are the only contents worked in the portuguese classrooms. These results are aligned with data from the case study: the number of school visitors increases when astronomy becomes more relevant in the curriculum, and decreases when otherwise; the majority of teachers in continuous training at PP-CCV did not have initial training in astronomy and state that prior to the course undertaken at PP-CCV did not have a particular interest in astronomy. Knowing the status quo of astronomy content in the national curriculum is only the first step to address a potential major problem for the future of portuguese astronomy. The consequences for astronomy education are clear, but it also impacts strongly on astronomy dissemination in science centers and, at the end of the chain, it impacts astronomy research itself, as the option of following a career path in astronomy research becomes less probable. That all stakeholders of national astronomy place this issue high in their agendas seems indispensable in order to ensure the future of portuguese astronomy and its role in society. That future depends on a very dynamic community of astronomers that leverage the opportunities arising for industry, following the portuguese participation in the European Southern Observatory (ESO) and in the European Space Agency (ESA). It is not possible to develop a strong technological and industrial development component, without a strong community of professional astronomers, which in turn, depends on effective astronomy education and dissemination practices throughout all school years.

ID 60

Title: Inclusion and Diversity: the European Astronomical Society Inclusion Working Group

Author: S. Anjos

Abstract: The EAS Working Group on Diversity and Inclusion was established in 2019 with the primary goal of raising awareness about various issues related to diversity, equity and inclusion in astronomy. These issues include (but are not limited to) race, gender, gender identity, disability, socioeconomic background, nationality, ethnicity, neurodiversity, religion, and any intersections between them. Diversity brings several benefits to organisations: less work withdrawal, less mental illness, more creativity and productivity, among others. Therefore, for organisations, promoting diversity and inclusion should be a priority. By creating this group, EAS aims to make diversity an opportunity to a truly inclusive collaborative research environment. Currently with 12 members, the IWG serves to provide advice, strategies, statements, policies, activities and programs as they deem appropriate to both the Council and to the Membership, so that the EAS can achieve these goals as a society. Reflecting on barriers to enter and being successful in academia, the IWG aims to identify best practices, tools, and methods to overcome misconceptions and stereotypes observed in the field of astronomy. Over the past year, the IWG has met frequently to share information, developing various initiatives such as workshops and the mentoring programme. In this talk we will present the main goals, tasks and challenges that the IWG faces, as well as the main activities it develops related to Diversity and Inclusion. In doing so we intend to emphasize the importance of bringing to the SPA agenda issues related to diversity and inclusion in the astronomy community in Portugal.

ID 61

Title: Astronomy: A path to Science Teaching

Author: Á. M. F. Ferreira

Abstract: The speed with which the contemporary world changes demands a reformulation of paradigms and practices in School, in order to respond to the challenges and needs of our times. In this context, the portuguese ministry of education presented a set of measures, in line with international guidelines, with the purpose of promoting interdisciplinary strategies, research skills and critical thinking, to prepare students for the demands of contemporary society. But how to operationalize these measures in the field? Astronomy, due to its fascination and its interdisciplinary nature, presents itself as a possible answer to this problem. Astronomy may be used, not only for explaining simple phenomena in our daily lives, such as the seasons, the phases of the Moon, the tides, and many other phenomena that have accompanied us since we were born, to approaches to Physics and Mathematic concepts presented on Cosmology, and life in Space, be it about chemical “bricks” for the existence of life, or about aspects related to the daily lives of astronauts in Space Missions. The impact of scientific and technological development which is verified through the transfer of knowledge from Space Research to areas such as Medicine, transports, public safety, consumables, computer technology, weather forecast, industrial productivity, and many others. So, Astronomy and Space Sciences allows the development of a myriad of educational activities and projects, which can advantageously be developed in an interdisciplinary way, contributing to the mobilization of multiple skills such as the integration of knowledge from different disciplinary areas, critical evaluation of procedures and results, autonomy and responsibility. My work on this topic is set a variety of hands-on and minds-on activities, on the hat of Astronomy, to work on scientific projects and activities at school, applied with interdisciplinary approaches within the scope of Curriculum Flexibility and the Profile of Students Leaving Mandatory Schooling” (Portuguese Law- Dispatch n.º 6478/2017, 26th july).

ID 65

Title: Stellar populations of massive young clusters using supervised machine learning

Author: K. Muzic

Abstract: Massive young star clusters are fundamental building blocks of galaxies, and the most abundant reservoirs of newly born stars in the Milky Way. A robust membership assignment is fundamental to study their populations and physical properties, since in the plane of the sky cluster members are often significantly outnumbered by Galactic field stars, as well as by faint distant galaxies. Traditionally, various methods have been used to separate these, including the presence of X-ray emission, infrared excess, spectroscopic youth features, and, to a lesser extent, proper motions. With the advent of the Gaia mission and its precision astrometry, we are now able to study complete stellar populations in massive young clusters at kpc distances, over areas much larger than ever before. In this contribution, I will present an application of the Pobabilistic Random Forest algorithm to study the stellar population of the young massive cluster NGC 2244. The large sample of identified member candidates allows us to derive the most complete Initial Mass Function to date, study the spatial structure of the region, and the effects of mass segregation.

ID 68

Title: Particle-in-cell simulations of laser-driven, ion-scale magnetospheres in laboratory plasmas

Author: F. Cruz

Abstract: Ion-scale magnetospheres have been observed around comets, weakly-magnetized asteroids, and localized regions on the Moon. These mini-magnetospheres provide a unique environment to study kinetic-scale plasma physics, in particular in the collisionless regime. In this work, we present collisionless particle-in-cell (PIC) simulations of ion-scale magnetospheres that reproduce recent laboratory experiments performed on the Large Plasma Device (LAPD) at UCLA. Utilising high-repetition rate lasers to drive super-Alfvènic plasma flows into a dipole magnetic field embedded in a uniform background magnetic field, these experiments examine the evolution of local and global magnetosphere structures for a range of dipole and upstream parameters. PIC simulations are employed to interpret highly-resolved, volumetric experimental datasets, and used to determine the magnetospheric structure, magnetopause location and kinetic-scale structures of the plasma current distribution, under different plasma and magnetic field parameters. Different plasma densities are considered to evaluate the effects of plasma coupling in the results. F. D. C., F. C. and L. O. S. are supported by the European Research Council (ERC-2015-AdG Grant 695088). Experiments were supported by the NSF.

ID 69

Title: Probing the effects of environment on star and brown dwarf formation

Author: K. Kubiak

Abstract: Brown dwarfs are a critical link between the realms of stars and planets. Their formation process is one of the crucial missing pieces in our understanding of how star and planet formation work. Understanding the origin of brown dwarfs is the main motivation for recent deep studies of star-forming regions and young clusters. The major question driving our studies is whether the birth environment affects their formation efficiency, as predicted in several formation scenarios. The expectation is that high gas or stellar densities or the presence of massive OB stars may be factors that boost the incidence of newly formed brown dwarfs with respect to stars. To address this question we investigate the stellar and sub-stellar objects in the drastically different environments of massive young clusters RCW 38 and NGC 2244 and that of nearby star-forming regions. Here we will present the current status of young brown dwarf studies, compare the low-mass Initial Mass Functions in a variety of Milky Way environments. For RCW38, we will address the high-mass IMF and the shallow slope that we see in the center (mass segregation or not?). We will summarised the implications of these results for our understanding of sub-stellar formation processes.

ID 73

Title: Youth analysis of near infrared spectra of young low-mass stars and brown dwarfs: three case scenarios

Author: V. Almendros-Abad

Abstract: The formation of low mass stars and brown dwarfs can be studied through comparison of the low mass population statistics of young clusters across different environments. Robust low mass populations of young clusters need to be obtained through near infrared spectroscopy, where the low-mass and young nature of member candidates can be confirmed. The spectroscopic analysis of these objects is not performed in a uniform manner, and the assessment of youth generally relies on the visual inspection of youth features whose behavior is not so well understood. In this contribution we will present our efforts to develop a uniform method for the derivation of the spectral type and extinction of low-mass dwarfs. We will also present a novel method to evaluate youth of low-mass stars and brown dwarfs using spectral indices and machine learning techniques where we derive the relative importance of each youth feature. Lastly, we will present three different case scenarios where we have applied this methodology: brown dwarf population of young clusters NGC 2244 and NGC 2264, and a very peculiar brown dwarf member of the young cluster rho ophiuchus that challenges our knowledge of these objects.

ID 74

Title: Gaussian processes regression networks - Results on the RV observations of the Sun

Author: J. Camacho

Abstract: Since the discovery of the first extrasolar planet in 1995, Doppler spectroscopy proved to be one of the most successful methods in the search for exoplanets. Unfortunately, the search for exoplanets comes with several challenges. Stellar signals usually contaminate the radial velocity (RV) measurements. These need to be treated as they can hide or mimic planetary signals. Gaussian processes (GP) proved to be an excellent tool for this task. With it, one can model the stellar component of the signal and infer the number and properties of the existing planetary signals.

A framework extending to the capabilities of the GP is known as Gaussian process regression networks (GPRN). This framework extends the concept of GP analysis to any number of time series. The main idea is to use the information contained on existing activity indicators (e.g log R’hk) to separate the activity and planetary components of the RV time series.

Having developed a python implementation of a GPRN framework, we thus present the final structure of our new tool and the results obtained on RV observations of the Sun and its consequences to the analysis of other stars.

ID 75

Title: Hunting for Brown Dwarfs in Corona Australis

Author: A. G. C. Baptista

Abstract: Young brown dwarfs provide an insight into the formation of both planets and stars. Statistical analysis of large samples of these objects is fundamental to determine the relative contribution of known brown dwarf formation models. They also help constrain the lower-end of the Initial Mass Function of cloud complexes, which is well characterized for nearby star-forming regions down to 10 – 20 Jupiter masses but, for masses below that where star- and planet-formation overlap, is still loosely defined. The SONYC (Substellar Objects in Nearby Young Clusters) survey aims to produce a complete census of substellar objects in nearby star-forming regions. Having conducted studies in five different regions so far, the next step pertains to the Corona Australis cloud. In this work, the photometry study of a dataset produced by the Suprime-Cam at the Subaru telescope in Hawaii is presented. The data reduction and photometric characterization of this dataset resulted in a list of candidate objects for future spectroscopic efforts. In this list, there are about 70 potential candidates for the free-floating planetary-mass brown dwarfs with masses below 5 Jupiter masses, providing the deepest look into the Corona Australis region to date.