# Congresso Nazionale di Astrochimica e Astrobiologia (proto-) planetaria

UTC
Castello di Duino

#### Castello di Duino

Frazione Duino, 32, 34011 Duino-Aurisina, Trieste https://castellodiduino.it
Description

### Dal 21 al 23 Ottobre si terrà a Trieste il primo convegno nazionale sull'evoluzione chimico-fisica dalle fasi proto-stellari alle atmosfere (eso-)planetarie, riunendo la comunità italiana che si occupa di astrochimica protostellare e protoplanetaria, della formazione e composizione dei pianeti e dei piccoli corpi del Sistema Solare, di atmosfere eso-planetarie e di astrobiologia. Partendo dalle osservazioni da terra (e.g., con ALMA) delle prime fasi evolutive, passando per l'esplorazione dei corpi del Sistema Solare (e.g., JUNO, Rosetta, Dawn, ExoMars, Cassini e Gaia), coadiuvati dagli studi di laboratorio, l'obiettivo principale è di trovare dei punti sinergici tra questi ambiti complementari e di preparare la comunità italiana (e le nuove generazioni) alla data exploitation delle future osservazioni sia da terra che da spazio.

Participants
• Aldo Stefano Bonomo
• Alessandra Rotundi
• Alessandro Sozzetti
• Alfredo Biagini
• Andrea Raponi
• Antonella Barucci
• Antonio Garufi
• assimo maris
• Barbara Michela Giuliano
• Caterina Boccato
• Cecilia Ceccarelli
• Chiara Mininni
• Claudio Codella
• Cristian Carli
• Daniela Ascenzi
• Davide Fedele
• Diego Turrini
• Elena Mazzotta Epifani
• Elena Redaelli
• Eleonora Alei
• Eleonora Bianchi
• Emanuele Pace
• Eugenio Schisano
• Fabiola Antonietta Gerosa
• Fabrizio Capaccioni
• Filippo Tamassia
• Francesca Perrotta
• Francesco Borsa
• Francesco Fontani
• Francesco Lazzarotto
• Gianfranco Magni
• Giovanna Rinaldi
• Giovanni Poggiali
• Giovanni Strazzulla
• Giusi Micela
• Gloria Guilluy
• GRAZIANO CHIARO
• Isabella Pagano
• John Robert Brucato
• Laura Affer
• Laura Colzi
• Laura Inno
• Laura Silva
• Linda Podio
• Lorenzo Betti
• Luca Bizzocchi
• Luca Evangelisti
• Luca Naponiello
• Luca Tornatore
• Luis Diego Pinto
• Marcel Snels
• Marco Fulle
• maria teresa rosa capria
• Maria Angela Corazzi
• Maria Di Paolo
• MariaElisabetta Palumbo
• Matteo Brogi
• Matteo Pinamonti
• Mattia Melosso
• Mauro Ciarniello
• Michelangelo Formisano
• Michele Maris
• Riccardo Claudi
• Riccardo Giovanni Urso
• Rosario Brunetto
• Serena Benatti
• Sergio Molinari
• SIMONE IEVA
• Sonia Melandri
• Stavro Lambrov Ivanovski
• Stefania Stefani
• Valentina D'Orazi
• Valerio Nascimbeni
• Vito Mennella
• Víctor M. Rivilla
• Monday, 21 October
• Protostellar chemistry
• 9:30 AM
Welcome
• 1
Astrochemical origins: the (potential) heritage from proto- stellar and planetary eons

The first detection of an interstellar diatomic molecule came as a surprise, given the harsh conditions of the interstellar medium. Eighty years later, more than 50 interstellar molecules with six atoms or more have been discovered, almost half of which in regions that will eventually form planetary systems like our own Solar System. What is more, the backbone of all these large molecules, called interstellar Complex Organic Molecules or iCOMs, is made up of carbon atoms. Add to that the ubiquity of water in solar-like forming planetary systems and the cocktail for the potential emergence of life is served. Seen with the eyes of an astrochemist, terrestrial life just used what is abundantly available in solar-like star forming regions. One can even reverse the point of view: what is available gave rise to life and this implies that life is not a one-shot event in the history of the Universe.

In this contribution, I will review the molecular content likely available when the Solar System started its million years long process of formation and what was probably passed to the young Earth. Whether and what of it was directly used for triggering life is beyond astrochemistry, but nobody can answer a question if all the data of the problem are not known.

Speaker: Prof. Cecilia Ceccarelli (University of Grenobles Alpes)
• 2
GUAPOS: G31.41+0.31 Unbiased ALMA sPectral Observational Survey

Some of the best sources to study the richness and complexity of chemistry in the interstellar medium, are Hot Molecular Cores (HMCs), the birthplaces of high mass stars. Spectra of these sources show a very high density of molecular lines, including emission from hydrogenated species, O-bearing species, N-bearing species, deuterated molecules and interstellar Complex Organic Molecules (iCOMs) (e.g. Belloche et al. 2013).
Spectral surveys in HMCs have been carried out mostly towards Sgr B2 (Sánchez-Monge et al. 2017; Belloche et al. 2013), but this source can not be considered as a template for typical HMCs in the Galaxy, since its proximity to the Galactic Center leads to peculiar environmental conditions, that could indeed have an impact on the chemistry. Here we present the project GUAPOS (G31.41+0.31 Unbiased ALMA sPectral Observational Survey), a full ALMA Band 3 spectral survey with a resolution of 1.2" towards G31.41+0.31 (G31), one of the most well-known and chemically-rich HMC in the Galaxy (Beltrán et al. 2009, Cesaroni et al. 2010, Rivilla et al. 2017, Beltrán et al. 2018), located at a distance of 3.7 kpc, with a luminosity $\geq10^{4}L_{\odot}$ (Beltrán et al. 2005) and with no UC HII region embedded on it (Cesaroni et al. 2010). The spectrum of the GUAPOS project, covering the spectral interval $\sim$ 84 - 116 GHz with a spectral resolution of $\sim$500 kHz, shows a very rich chemistry with a high density of spectral lines which has led to the identification of 16 iCOMs. Among them, we detected the three isomers of $\mathrm{C_{2}H_{4}O_{2}}$: glycolaldehyde, methyl formate and acetic acid (see Fig. 1). The analysis on these important pre-biotic molecules would allow us to understand more about the preferential pathways that lead to the different isomers formation.

References:
$\bullet$ Belloche et al. 2013, A&A 559, A47
$\bullet$ Sánchez-Monge et al. 2017, A&A 604, A6
$\bullet$ Beltrán et al. 2018, A&A 615, A141
$\bullet$ Beltrán et al. 2005, A&A 435, 901
$\bullet$ Cesaroni et al. 2010, A&A 509, A50
$\bullet$ Beltrán et al. 2009, ApJ 690, L93
$\bullet$ Rivilla et al. 2017, A&A 598, A59

Speaker: Chiara Mininni (Università degli Studi di Firenze - INAF)
• 3
Jet-driven and accretion shocks as factories of interstellar complex organics around Sun-like precursors

The role of the pre-solar chemistry in the chemical composition of the Solar System bodies is far to be understood. Which is the importance of presolar heritage? The molecular complexity builds up at each step of the process leading to star formation, starting from simple molecules and ending up in interstellar Complex Organic Molecules (iCOMs). How these molecules are formed in the harsh conditions of the interstellar medium is still far to be fully understood. The two current theories predict formation by reactions in the gas phase or on the interstellar dust grains. To attack these questions, it is of paramount importance to combine high-sensitivity unbiased spectral survey to collect large numbers of lines for each iCOM (for reliable identifications and to analyse excitation conditions) as well as to image their spatial distribution to investigate their association with different ingredients of the Sun-like star formation recipe (e.g. warm envelopes and cavities opened from hot jets, accretion disks, disk winds).

In this context, protostellar shocks can be considered perfect astrochemical laboratories due to sputtering and shuttering leading to the erosion of the grain cores and ices, and consequently to the chemical enrichment of the gas phase. Basically, we have to deal with two kind of shocks: (i) high-velocity shocks produced by protostellar jets, and (ii) slow accretion shocks located close to the centrifugal barrier of the accretion protostellar disks. Both shocks are factories of iCOMs, which can be then efficiently used to follow both the kinematics and the chemistry of the inner (less than 50 au) protostellar systems. Thanks to the combination of the high-sensitivities and high-angular resolutions provided by the advent of new telescopes such as ALMA and NOEMA, it is now possible to image in details the earliest stages of the Sun-like star formation, inspecting the region place where planets, asteroids, and comets will form. With this in mind, we will discuss recent results obtained in the framework of several Large Programs at mm and sub-mm wavelengths, such as IRAM-ASAI, IRAM-SOLIS, and the first ALMA LP on astrochemistry is Sun-like star gorming regions, FAUST.

Speaker: Claudio Codella (Istituto Nazionale di Astrofisica (INAF))
• 4
Enhanced nitrogen fractionation at core scales: the high-mass star-forming region IRAS 05358+3543

It is well known that the $^{14}$N/$^{15}$N isotopic ratio found for the proto-Solar nebula (PSN), 440 (Marty et al. 2010), is significantly higher than that measured in pristine Solar System materials, like comets ($\sim$140, Hily-Blant et al. 2017 and references therein) and carbonaceous chondrites ($\sim$50-250, e.g. van Kooten et al. 2017). This suggests a local chemical enrichment of $^{15}$N during the Sun formation process. However, the cause of this enrichment and its relation with the natal clump are still uncertain.
Since there is growing evidence pointing out that our Sun was born in a rich cluster containing massive stars (e.g. Adams 2010), we have studied the $^{14}$N/$^{15}$N ratio in a large sample of high-mass star forming regions.
In this talk I will first show the overall behaviour of the $^{14}$N/$^{15}$N ratio across the Galaxy (Colzi et al. 2018a, Colzi et al. 2018b). We have confirmed, based on a solid statistics for the first time, that the $^{14}$N/$^{15}$N ratio increases with the Galactocentric distance as a consequence of the Galactic chemical evolution. Moreover, we have estimated that the $^{14}$N/$^{15}$N ratio in the local interstellar medium is about 400, i.e. very close to the PSN value. Then, I will zoom-in into the massive star-forming protocluster IRAS 05358+3543, where we have obtained the first interferometric maps of N-fractionation combining single-dish and high-resolution interferometric observations of the $^{15}$N isotopologues of N$_{2}$H$^{+}$ (Colzi et al. 2019, see Fig. in attachment). The analysis yields $^{14}$N/$^{15}$N ratios of 100-200 in the cores, and higher values of $\ge$200 in the diffuse clump gas. This result, which strongly suggests a local chemical enrichment of $^{15}$N at core-scales, helps us to understand how the chemical inventory evolves from the parental molecular reservoir to smaller-scale objects, in which star-formation occurs. It suggests also that the $^{15}$N-enrichment measured in the pristine Solar System material could occur locally, in the environment in which the Sun was born, during the protocluster evolution.

References

• Adams, F. C. 2010, ARA&A, 48, 74
• Colzi, L., et al., 2018a, A&A 609, A129
• Colzi, L., et al., 2018b, MNRAS, 478, 3, p.3693-3720
• Colzi, L., et al., 2019, MNRAS, 485, 4, p.5543-5558
• Hily-Blant, P., et al., 2017, A&A 603, L6
• Marty B. et al., 2010, Geoch. Cosmoch. Acta, 74, 340
• van Kooten E. M. M. E. et al., 2017, Geoch, Cosmoch. Acta, 205, 119
Speaker: Ms Laura Colzi (Università degli Studi di Firenze)
• 5
Deuterium enrichment of interstellar complex organic molecules in gas-phase chemistry

Since the first attempts to explain the abundance of deuterated species in interstellar objects, it has been assumed that gas-phase reactions involving partially or per-deuterated species occur with the same efficiency as those involving molecules containing only protium (Millar, Bennet, Herbst, 1989). Not only that: in the cases where two or more sets of products are possible, the yield is always assumed to be the same for each channel. Back to the first astrochemical models, not much was known on the kinetic isotopic effects (KIEs) for interstellar reactions. In addition to that, the backbone of astrochemical models was mostly constituted by very exothermic ion-molecule reactions and a strong KIE is expected only for tunneling-dominated reactions, that is, reactions characterized by an entrance barrier which are not expected to be relevant in the context of interstellar chemistry. As admitted by Millar, Bennet, Herbst, however, both assumptions are very crude, even if they are believed to be good enough to treat the (huge) enhancement of D/H in trace molecules caused by physical parameters.
In the last decade, new observations of deuterated interstellar complex organic molecules (iCOMs) have become common, but most available astrochemical models failed to reproduce the observed abundances of iCOMS which spans from 1% to 8% (see the recent paper by Jorgensen et al., 2018). Therefore, it is time to reconsider the role of KIE. In this contribution, we present the cases of two common iCOMs, namely formamide (Skouteris et al. 2017) and dimethyl ether (Skouteris et al. 2019). As we are going to see, KIEs in gas-phase reactions are able to explain the observed abundance of deuterated formamide and dimethyl ether, thus implying that these species are actually formed in the gas-phase rather than on interstellar ice surface.
Millar TJ, Bennet A, Herbst E, 1989, ApJ, 340, 906
Jorgensen JK et al., 2018, A&A, 620, A170
Skouteris D. et al, 2017, MNRAS, 468, L1
Skouteris D et al, 2019, MNRAS,482, 3567

Speaker: Prof. Nadia Balucani (DCBB - Università degli Studi di Perugia)
• 6
Deuterated amidogen in the laboratory and in Space

Light nitrogen hydrides as imidogen (NH), amidogen (NH$_2$) and ammonia (NH$_3$) are located at the very beginning of the reaction network which leads to the formation of complex species, and are thus of primary importance to constrain the models describing nitrogen chemistry in the ISM. They are formed by a chain of hydrogen abstraction reactions starting from:

N$^+$ + H$_2$ $\longrightarrow$ NH$^+$ + H , $\ldots$

which also produces the ions NH$_2^+$ NH$_3^+$ and NH$_4^+$, and then the corresponding neutral hydrides by dissociative recombination. If H$_2$ is replaced with its singly deuterated form HD, this ion–neutral process has a much reduced endothermicity and can thus drive deuterium into the molecular form, enhancing the abundance of ND, NHD, and the NH$_n$D$_{3-n}$ isotopologues.
Amidogen (NH$_2$) has been detected in the interstellar medium: towards the massive star forming region SgrB2 [1], and in the low-mass proto-binary system IRAS 16293-2422 [2]. On the other hand, its deuterated variants NHD and ND$_2$ have not been identified in Space to date due to the incomplete knowledge of their rotational spectrum. Recent laboratory studies performed in Bologna [3] and at MPE Garching [4] have provided very accurate rest-frequencies for these isotopologues at sub-millimetre and THz regimes, thus allowing for sound searches for their spectral features in Herschel/HIFI archival data.
Accurately examining the spectral scan observations performed towards IRAS16293-2422 on the framework of the CHESS Herschel key project [5], we tentatively identified for the first time singly- and doubly-deuterated amidogen in an astrophysical source. The $1_{11}-0_{00}$, $J=3/2-1/2$ line of NHD and the $2_{12}-1_{01}$, $J=5/2-3/2$ line of ND$_2$ were detected in absorption towards the protostar sub-millimetre continuum. The hyperfine analysis of NHD and ND$_2$ spectral patterns, together with a reanalysis of the NH$_2$ spectrum, provided a measure of the amidogen deuteration in this proto-stellar environment.

References:
[1] E.F. van Dishoeck, D.J. Jansen, P. Schilke and T.G. Philips, ApJ, 416, L83 (1993)
[2] P. Hily-Blant, S. Maret, A. Bacmann, et al., A&A, 521, L52 (2010)
[3] M. Melosso, C. Degli Esposti, L. Dore, ApJS, 233, 15 (2017)
[4] L. Bizzocchi et al., manuscript in preparation
[5] C. Ceccarelli, A. Bacmann, A. Boogert, et al., A&A, 521, L22 (2010)

Speaker: Luca Bizzocchi (Max-Planck-Institut für extraterrestrische Physik)
• 12:45 PM
Lunch
• Protoplanetary disks
• 7
The chemical composition of protoplanetary disks

Protoplanetary disks contain the ingredients for the bulk and atmospheric composition of planets. Addressing the physical conditions and chemical composition of disks is thus important to understand the origin of planets and their atmospheres. In particular, it is debated to what extent planets (a) inherit their composition directly from the interstellar medium (inheritance) or (b) whether there is a chemical reset during the collapse of the molecular cloud and the formation of the disk (reset). Both regimes are likely to take place simultaneously in disks across different spatial regions.
Multi-wavelength observations give us insights on the chemical compositions in different region of the disk at the time of planet formation: infrared spectroscopic observations are sensitive to the warm (gas temperature > 100 K) disk region (mostly the uppermost layers) while observations in the (sub-)millimeter range trace the cold gas phase component in the disk interior.
A major role in this field is played by the Atacama Large Millimeter Array (ALMA) thanks to its unprecedented sensitivity and angular resolution. I will present some recent ALMA results in terms of chemical composition, radial distribution of molecules and elemental abundance ratios.

Speaker: Davide Fedele (Istituto Nazionale di Astrofisica (INAF))
• 8
Organic molecules in planet-forming disks

A key open question in astrochemistry is how chemical complexity increases during the formation process of Sun-like stars from prestellar cores to protoplanetary disks and ultimately to planets. Is the chemical composition of planets inherited from the prestellar and protostellar stages? Or does it reflect chemical processes occurring in the disk? Are organics efficiently formed in disks and by what mechanism(s)?

The chemistry of disks is difficult to probe observationally due to their small sizes (~100 au) and to the low gas-phase abundance of (complex) organic molecules (COMs) (down to 1e-12). It is only with the advent of millimetre interferometers such as ALMA that we started to unveil the disks molecular content at unprecedented angular resolution and sensitivity.
ALMA observations of the protoplanetary disk of DG Tau in the Taurus star forming region allowed to recover the spatial distribution and the abundance of the H$_2$CO, CS, and CN molecules at ~20 au resolution. The CS and H$_2$CO molecules show a ring of emission at the edge of the millimetre dust continuum. This suggests: (i) efficient formation of organic molecules by CO hydrogenation on the grain surfaces beyond the CO snowline (T $< 20$ K at R $>30$ au); (ii) enhanced desorption of organics and S-bearing molecules in the outer disk caused by increased UV penetration and/or temperature inversion; (iii) a CH$_3$OH/H$_2$CO abundance ratio $<1$ in agreement with the predictions of disk chemistry models. Moreover, the “molecular-ring” is located beyond a “dust-ring”, with a change of orientation of the continuum polarization, supporting a tight link between the disk chemistry and the dust properties.

This pilot project paves the way to a large campaign to characterise the molecular content of protoplanetary disks and to comprehend the organic composition inherited by the planets assembled in the disks.

Speaker: Dr Linda Podio (INAF - Osservatorio Astrofisico di Arcetri)
• 9
Dust dynamics in protoplanetary disks: dust evolution timescales and constraints on dust grain size distribution in the dust vertical settlement regions.

We propose a cross-disciplinary study of dust dynamics and the observed gas tracers using the VLT-X-Shooter and VLT-CRIRES data (Alcala et al. 2017) in which we will explot that will transfer know-how and methods derived from recent advancements in the field of Solar System investigations to the study of circumstellar discs. It is a theoretical modelling of the dust dynamical evolution in the Epstein regime that will provide a unique perspective of the dust evolution in circumstellar discs and will allow us to explore for the first time how non-spherical dust grains can be injected and sustained in a vertically extended region spanning several AU from the mid-plane. One direct application of the proposed research is the investigation of the dynamics of secondly generated dust, collisionally produced in HD163296 (Turrini et al. 2019). This dust will find itself in a comparatively gas-poor environment and its dynamical evolution will be more similar to that of dust grains in a rarefied gas field (Ivanovski et al. 2017) than to that occurring in the denser mid-plane region. Consequently, a model that simulates such dust dynamics will be able to describe its evolution and to constrain the dust grain size distribution in the dust vertical settlement regions.

References:
Alcala et al. 2017, Astronomy and Astrophysics, Volume 600, id.A20, 42 pp.
Turrini et al. 2019, Astrophyisical Journal, Vol. 877, n.1
Ivanovski et al. 2017, Icarus 282, 333-350

Speaker: Dr Stavro Lambrov Ivanovski (INAF - Osservatorio Astronomico di Trieste)
• 10
Young Protoplanetary disks evolving in open clusters: SPH treatment with radiative transfer formalism and applications to the first evolutionary phases of the star

Protoplanetary disks constitute the primordial environment for the formation of the many planet systems observed up to now. Recent dynamical investigations (see Pfalzner & al, 2015) suggest that the Solar System has been formed in an Open Cluster. This idea has been corroborated by the many recent observations of both disks and planetary systems around stars in open clusters (see, for example Hernández & al, 2010; Mann & al, 2015). A potential new scenario for the planet formation has thus been opened, according to which protoplanetary disks do not evolve as isolated systems but rather may feel the presence of other stars. This scenario has also relevance for the study of mixing and transport of matter within the disk. In particular, of high interest are the mechanisms for the outward transport of high temperature minerals formed close to the Sun and embedded in cometary nuclei formed at large distances from the Sun (Brownlee & al, 2006).
To follow in details the history of a star with a protoplanetary disk embedded in an Open Cluster, we developed a hydrodynamical lagrangian code named GaSPH (see Pinto & al, 2019) through which we evolve the matter of the disk according to the Smoothed Particle Hydrodynamics (SPH) scheme; the disk is self-gravitating, that is takes in proper account the internal gas gravity and the gas-star mutual gravity, and the evolution of a limited number of point-mass objects (which may represent both stars or planets) is treated with a high order explicit method.
The model includes also a radiative transfer SPH scheme (following the schematization of Bastien & al, 2006), which, by assuming that the disk is irradiated by a central star of given temperature and luminosity, allows to describe a physically reasonable propagation of radiation through matter. This addition is very important as the dust temperature is mainly set by the stellar luminosity, while the chemistry of the whole disk depends on the UV and X ray fluxes.

We will discuss our preliminary results applied to the study of the evolution of a protoplanetary disk in an open cluster. We perturb the system by letting it interact with a limited number of close stars, considering, in particular, the close encounter events.
We will focus in particular on the mixing of matter in the young solar environment due to the macroscopic transport of matter due to close fly-bys.

References:

Bastien, P., Cha, S. H., & Viau, S. 2004, in Revista Mexicana de Astronomia y Astrofisica Conference Series, ed. G. Garcia-Segura, G. Tenorio-Tagle, J. Franco, & H. W. Yorke, Vol. 22, 144–147
Brownlee, D., Tsou, P., Aléon, J., et al. 2006, 314, 1711
Hernández, J., Morales-Calderon, M., Calvet, N., et al. 2010, The Astrophysical Journal, 722, 1226
Mann, R. K., Andrews, S. M., Eisner, J. A., et al. 2015, The Astrophysical Journal, 802, 77
Pfalzner, S., Davies, M. B., Gounelle, M., et al. 2015, Physica Scripta, 90, 068001
Pinto, L. D., Capuzzo-Dolcetta, R., & Magni, G. 2019, arXiv e-prints, arXiv:1907.00358

Speaker: Dr Luis Diego Pinto (INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali)
• 11
Compositional signatures of the complex interactions between giant planets and planetesimals in protoplanetary disks

The formation process of planetesimals and giant planets is entwined with the evolution of the protoplanetary disks in which they are born. From the moment of their appearance, however, the interplay between giant planets and planetesimals contributes in shaping the characteristics of the surrounding protoplanetary disks. Signatures of these processes are left in the composition of both giant planets and circumstellar disk: in this talk we will present recent efforts within the Italian national community to study which compositional signatures can be used as windows into such still limitedly understood processes. Specifically, we will describe how modelling the dynamical and collisional evolution of the planetesimals embedded in the circumstellar disk of HD163296 in response to the formation of its giant planets allows for explaining the anomalies observed with ALMA in the abundance and distribution of its dust and in the composition of its gas. In parallel, we will introduce recent efforts in investigating how the same processes shaping HD163296 cause the enrichment in high-Z material of the atmospheric and envelope composition of giant planets during their formation. Particularly, we will discuss how the accreted material is characterized by an overall non-solar composition and describe ongoing activities in the framework of the ESA mission ARIEL and the NASA mission JUNO to unravel the information provided by the different elements contributing to the envelope and atmospheric enrichment.

Speaker: Dr Diego Turrini (INAF-IAPS)
• 4:15 PM
Coffee break & Poster
• Solar System
• 12
Asteroid composition: recent results by the JAXA Hayabusa2 and NASA OSIRIS-REx missions

The investigation of asteroids remains one of the major topics of planetary science. As primitive leftover building blocks of the solar system formation process, they offer clues to the chemical mixture from which the planets formed some 4.6 billion years ago and provide information on the development of life on Earth.

Several asteroids have been observed by space missions, but the majority of knowledge on asteroid composition is obtained, still today, by ground spectroscopy and analysed as taxonomic trends. The taxonomical classes have been defined and associated to meteorites, giving the asteroid mineralogy composition on the basis of meteoritic laboratory analysis. Nevertheless, about 2/3 of the mass of the asteroid belt seems absent from our meteorite collections, in particular for those taxonomical classes associated to the dark primitive objects, rich in volatiles and organics.

The two missions Hayabusa2 and OSIRIS-REx, respectively launched by JAXA and NASA, will return samples from the primitive asteroids Ryugu and Bennu to revolutionize our understanding of the primitive matter of the solar system.

Ryugu and Bennu have primitive surfaces with very dark albedo (4.4 % and 4.5 % respectively) (Watanabe et al. 2019, Science 364, 268, and Lauretta et al. 2019, Nature 568, 55). Both objects have a spinning-top shape with an equatorial ridge, low density, and high porosity and are consistent with a rubble-pile structure.

The analysis of the present missions’ data shows two objects with different compositional and geomorphological properties. The preliminary spectroscopic data for both asteroids show spectral similarity with those of CM and/or CI meteorites. However, Bennu has a higher content of water-bearing minerals. The discovery of particle ejection from Bennu’s surface by the OSIRIS-Rex team indicate that Bennu is an active asteroid.

The samples returned to Earth from the two asteroids, together with the data analysis from the Rosetta and Stardust missions, will allow us to better understand the origin of the solar system and the relation between asteroids and comets.

Speaker: Prof. Antonella Barucci (LESIA - Paris Observatory)
• 13
Composition of Solar System giant planets

in progress

• 14
Spectral modelling and compositional properties of Saturn’s icy moons and rings

The Cassini spacecraft orbited in the Saturnian System from July 2004 to the end of the mission in September 2017. During almost thirteen years of survey, the VIMS (Visible and Infrared Mapping Spectrometer) experiment (Brown et al., 2004), provided a complete sampling of the spectrophotometric properties of Saturn’s icy moons and rings in the VIS-IR wavelength range (0.35-5.1 µm). These vast set of observations revealed surface compositions dominated by water ice, contaminated with variable amounts of chromophores (e.g. tholins and iron oxides) and darkening compounds (e.g. carbonaceous materials, silicates, iron and sulphides), whose final nature it’s still debated (Ciarniello et al., 2011; Filacchione et al., 2012; Clark et al., 2012; Buratti et al., 2019).

Spectral variability across the icy bodies in the Saturn’s system has been investigated so far by means of spectral indicators (e.g. spectral slopes at visible and infrared wavelengths, spectral ratios and band depth absorption features) aimed at characterizing relative variations in water ice grains size, contaminants abundances and mixing modality of these phases (Filacchione et al., 2012, Filacchione et al., 2013). In addition, the spectra of selected targets, as the major icy moon (Thetys, Enceladus, Mimas, Rhea and Dione) and rings (A, B and C) have been investigated separately by means of radiative transfer models (Ciarniello et al., 2011; Filacchione et al., 2012; Ciarniello et al., 2019) to provide quantitative constraints on the compositional properties of the observed surfaces.

In this work, we plan to harmonize and integrate the results of these previous studies. This will require a refinement of the present spectral models of the icy moons, after the application of recently developed photometric corrections (Filacchione et al., 2018a, b), which are meant to minimize non-compositional spectral variations induced by observations geometry. Hapke’s model (Hapke, 2012) will be applied to perform the spectral un-mixing, using as input the optical properties (refractive index or regolith’ single scattering albedo) for a number of compounds of interest (crystalline water ice, carbon, iron, amorphous and crystalline silicates, tholins, sulphides, iron oxides) and simulating different mixing modalities (areal, intimate, intra-particle). The derived composition of the major moons will be investigated as a function of the radial distance from Saturn and compared to the one of the rings to evaluate whether the same compositional paradigm can be applied to these different classes of objects and how the Saturn’s environment affects their composition.

References:
Buratti, B. J., et al., 2019. Science 364, 6445, eaat2349.
Brown, R. H., et al., 2004. Space Sci. Rev. 115 (1–4), 111–168.
Ciarniello, M., et al., 2011. Icarus 214, 541–555.
Ciarniello, M., et al., 2019. Icarus 317, 242–265.
Clark, R.N., et al., 2012. Icarus 218, 831–860.
Filacchione, G., et al., 2012. Icarus 220 (2), 1064–1096.
Filacchione, G., et al. 2013. Astrophys. J. 766, 76–80 (2013).
Filacchione, G., et al. 2018. Geophysical Research Letters, 45:2184–2192.
Filacchione G., et al., 2018. Geophysical Research Letters, 45(13):6400–6407.
Hapke, B., 2012. Theory of Reflectance and Emittance Spectroscopy. Cambridge University Press.

Speaker: Dr Mauro Ciarniello (IAPS-INAF)
• 7:30 PM
Social dinner
• Tuesday, 22 October
• Solar System
• 15
Aliphatic organics on comet 67P/Churyumov-Gerasimenko: from interstellar dust to pristine solar system

The VIRTIS infrared spectra of the surface of comet 67P/Churyumov-Gerasimenko (67P/CG) display a wide absorption band in the range 2.8-3.6 μm, which has been associated to the presence of organic compounds [1, 2]. However, several instrumental effects have hindered, so far, the detailed interpretation of the molecules and compounds contributing to this band. In this work we first revise the calibration of the VIRTIS-M-IR instrument [3, 4] onboard the Rosetta spacecraft with the aim to improve the detection of low-contrast spectral features and the radiometric accuracy.
Multiple observations of the nucleus during the inbound part of 67P/CG’s orbit (August-September 2014) are processed to derive an average reflectance spectrum to minimize the Poissonian noise. This refined analysis reveals a complex internal structure within the wide 2.8-3.6 μm absorption feature. Individual sub-features can be unambiguously identified after correction. The strongest ones are centered at 3.1, 3.3, 3.38, 3.42, 3.47 µm.
Two main aspects of the refined average spectrum corroborate the so called “comet-asteroid continuum” hypothesis, blurring the distinction between different classes of objects:
1) clear evidence of aliphatic compounds (CH2 and CH3) is given by the presence of the 3.38, 3.42 and 3.47 μm absorption bands. These features have never been observed on a cometary nucleus before. The spectral properties of the aliphatic signatures have striking similarities to that of the Insoluble Organic Matter extracted from primitive Carbonaceous Chondrites;
2) the overall shape of the spectrum presents similarities with some main belt and outer solar system objects, in particular, the presence of absorptions at 3.1 μm and in the spectral range 3.3-3.4 μm.

Moreover, the aliphatic features observed on the 67P spectrum are compatible to typical aliphatic observed in the Interstellar medium.

These findings allow a better understanding of the formation and evolutionary processes by suggesting a genetic link between comets, other pristine solar system materials, and interstellar dust grains (Raponi et al., Science, submitted).

Acknowledgements
We thank the following institutions and agencies for support of this work: Italian Space Agency (ASI, Italy) Centre National d'Etudes Spatiales (CNES, France), DLR (Germany). This work takes advantage of the collaboration of the ISSI international team “Comet 67P/Churyumov-Gerasimenko Surface Composition as a Playground for Radiative Transfer Modeling and Laboratory Measurements”, number 397.

References:
[1] Capaccioni et al. (2015) - Science, 347.
[2] Quirico et al. (2016) - Icarus, 272, 32-47.
[3] Coradini et al. (2007) - Space Sci. Rev., 128, 529.
[4] Filacchione (2006) - PhD thesis.

Speaker: Andrea Raponi (Istituto Nazionale di Astrofisica (INAF))
• 16
Pebbles

In this talk I will review all Rosetta data supporting the conclusion that comets are built-up of pristine cm-sized pebbles and were formed in the solar proto-planetary disc after the Al26 decay by gentle gravitational collapses possibly driven by streaming instabilities.

Speaker: Dr marco fulle (INAF Trieste)
• 17
From protostars to protoplanetary disks: astrochemistry at work during the Class I phase

How the chemical complexity evolves during the process leading to the formation of a Sun and its planetary system? Is the chemical richness of a Solar-like planetary system (partially) inherited from the earliest stages or there is a complete chemical reset? A powerful way to start answering these questions is by comparing the observed astrochemical content in young protostars with that in comets, i.e. with the most pristine known material from which our Solar System formed.
The protostellar phase is characterized by the molecular complexity blooming: when the inner 100 au protostellar envelope are heated at temperatures larger than 100 K, dust mantles products thermally sublimate and enrich the chemical composition of the gas (the so-called hot-corino phase). In addition, dramatic changes in the molecular abundances are expected also because of a warm gas-chemistry at work. While hot-corinos in Class 0 sources are relatively well-known, very little has been done so far to study the overall composition of more evolved Class I sources, which represent the link between the protostellar stage and the planetary system formation.
We present here the chemical census in Class I sources obtained thanks to the synergy between the IRAM-30m ASAI and IRAM-NOEMA SOLIS Large Programs. The SOLIS interferometric observations are used to study the sources on a Solar System scale and are complemented by spectral surveys at thousands au scale performed with the single-dish telescope. The measured Class I molecular abundances are compared with those in Class 0 protostars as well as with that recently measured in the 67P/Churyumov–Gerasimenko comet. Future perspectives on Class I investigations in progress in the context of the astrochemical ALMA FAUST large program will be also reported.

Speaker: Eleonora Bianchi (Istituto Nazionale di Astrofisica (INAF))
• Laboratory astrochemistry
• 18
Primitive asteroids: irradiation and spectroscopy, in laboratory and in space

Primitive extraterrestrial materials are characterized by a large heterogeneity of composition at small scales. This heterogeneity is observed in the laboratory on some meteorites and interplanetary dust with different techniques. Among these, infrared micro-spectroscopy has the advantage of being totally non-destructive and allowing a direct comparison with the astronomical observations of the minor bodies of the Solar System. Thanks to recent developments of "Focal Plan Array" matrix detectors, high spatial resolution and short acquisition IR mapping and IR tomography are now possible. In this presentation I will show some recent measurements of FTIR spectral imaging on different extraterrestrial materials, obtained in collaboration with the SMIS beamline of the SOLEIL synchrotron (France).
In the second part I will present new spectral imaging data of meteorites irradiated in the laboratory with 40 keV ions, as a simulation of solar wind irradiation of the asteroid surfaces. Together with the irradiation effects measured in the particles of the asteroid Itokawa (collected by the Hayabusa mission), these experiments support the spectral interpretation of the observations of asteroids, to establish a link between asteroids and meteorites and to understand the energetic processes that modify the surfaces of the small bodies. In samples irradiated in the laboratory we observe spectral variations of organic and mineral components, as well as variations in albedo. These irradiation effects as a function of the dose are then compared on a micron-scale with the compositional heterogeneity of the original materials, to determine which spectral bands are more sensitive to the effects of space weathering.
The results will be discussed in the context of the asteroid sample return missions Hayabusa2 (JAXA) and OSIRIS-REx (NASA).

Speaker: Rosario Brunetto (IAS, CNRS, Orsay)
• 11:25 AM
Coffee break & Poster
• 19
Polyyne synthesis evidenced by VUV spectroscopy of hydrocarbon-rich ices irradiated with energetic electrons

We present some results obtained by measuring VUV photoabsorption spectra in the range 110-340 nm of hydrocarbon-bearing ices and their mixtures with nitrogen. Samples have been irradiated with energetic (1 keV) electrons simulating conditions relevant to the icy bodies of the Solar System and icy mantles on grains in the interstellar or circumstellar medium. Ices in different astrophysical environments are continuosly exposed to energetic processing by photons, electrons and ions that contribute, sometimes dominate, to their physico-chemical evolution.
The results of this study indicate that many molecules among which polyynes H(−C≡C−)nH, are produced after irradition of pure CH4, C2H4 and C2H6 ices. Cyanopolyynes are synthesized when mixtures with nitrogen are irradiated. In addition, irradiation causes a spectral reddening (absorbance increases more at the shorter wavelengths than at the higher ones) and the formation of an unvolatile residuum whose spectral colors in the VUV range have been measured.
Results are discussed with a view to their astrophysical relevance with particular emphasis to the icy surfaces of Pluto and other Trans Neptunian Objects.

Speaker: Prof. G. Strazzulla (INAF - Osservatorio Astroﬁsico di Catania, Italy)
• 20
LABORATORY ROTATIONAL SPECTROSCOPY OF FLEXIBLE ORGANIC MOLECULES FOR THEIR DETECTION IN SPACE: AMIDES AND THIOAMIDES

The identification and quantification of molecules in space relies on spectroscopic methods (in particular rotational spectroscopy) and laboratory work is essential to provide the community with the spectral features needed to analyze the cosmological surveys.
Many of the molecules searched for in space, are complex organic molecules, which show a high degree of molecular flexibility. The high number of low energy conformations and the presence of large amplitude motions on shallow potential energy surfaces are peculiar to this kind of systems giving rise to very complex rotational spectra, which represent a challenge for spectroscopic and computational methods.
Experimental strategies for the rotational spectroscopic study of flexible organic molecules include the use of the cold and isolated conditions of a free jet expansion and heated sources for the non-volatile systems while the computational methods must deal with complex conformational surfaces, large amplitude motions and tunneling splittings of the rotational transitions.
As examples, we will discuss amides and thioamides. Amides are organic compounds with the -CO-NH- chemical functional group, well known in biology as the results of linking reaction between two amino-acids to form a peptide bond. The smallest amides: formamide and acetamide have been already characterized in laboratory and then observed in the interstellar medium through radioastronomy measurements. The detection of larger amides and their Sulphur analogues (thioamides) in space, require a preliminary laboratory study, aimed at the detection and assignment of their rotational spectrum. Here we present the results of the investigations carried on some amides and thioamides using the supersonic expansion techniques in the range 59-118 GHz and the comparison of the recorded spectra with public available astronomical datasets.

Speaker: Sonia Melandri (Department of Chemistry "G. Ciamician", University of Bologna)
• 21
Direct measurement of complex refractive index of CO ice using terahertz pulsed spectroscopy

Experimentally determined optical constants and in particular absorption coefficients of astrophysical ice analogs in the terahertz region are missing. These data are very important to determine how the dust opacity changes when the grains are covered with ice mantles. Thus, more accurate mass determinations can be carried out using the dust continuum emission, especially in cold and dense regions where CO mainly resides in solid form on top of dust grain surfaces, forming thick icy mantles. We have measured the optical and dielectric properties in the THz region of interstellar ice analogs of astrophysically relevant species, starting with CO, using the time-domain pulsed THz spectroscopic technique (TPS). TPS has the unique advantage of being able to measure both the amplitude and phase of sub-picosecond THz pulses in a wide spectral range in a single measurement and, thus, to reconstruct directly the optical properties without the use of the Kramers-Kronig relations. Making use of a mathematical algorithm developed specifically for this project, we succeeded in the calculation of the CO ice optical properties from the THz spectral data. Based on these results, the dust opacity has been derived afterwards. The analysis of re corded data for other common ice components, such as water and carbon dioxide, is in progress.

Speaker: Dr Barbara Michela Giuliano (Max Planck Institute for Extraterrestrial Physics)
• 22
Laboratory studies on photo-processing and desorption of prebiotic molecules in space

Today thanks to the advent of large telescopes, an increasing number of gas phase complex molecules is observed in star forming regions, prestellar dense cores, circumstellar disks and winds [1, 2, 3]. Planets are formed in protoplanetary disks during the first millions of years of stellar evolution. Thus, it is important to understand if molecules observed in gas phase, are already available in the solid phase adsorbed on the surface of dust and which fraction of such molecules will end up in protoplanetary disks in newly formed planetesimal.
Among these molecules formamide ($HCONH_{2}$) can play a key role. Formamide like other molecules containing H, C, N and O, is considered a plausible pathway in the synthesis of biomolecules under prebiotic conditions and it is the simplest molecule containing the peptide linkage first detected in the gas phase in Orion-KL and $SgrB_{2}$ [4]. It is plausible that it is initially adsorbed on the surface of grains within these regions of star formation and then thermally desorbs into the gas phase. Interpretation of observations can benefit of laboratory activities where it is possible to study these molecules simulating and following space processes. In laboratory, we are studying the interaction between space relevant mineral surfaces and biomolecules in simulated space conditions investigating both photo-stability of molecules and thermal desorption process.
These studies will support the interpretation of molecule observations in star forming regions with the goal of understanding the role of the grain surface in driving prebiotic chemistry in space.

[1] Beltrán, M. T. et al. 2009, The Astrophysical Journal Letters, Vol. 690
[2] Rivilla, V. M. et al. 2017, Astronomy & Astrophysics, Vol. 598
[3] Codella, C. et al. 2015, Mon. Not. R. Astron. Soc., Vol. 449
[4] Nummelin, A. et al. 1998, The Astrophysical Journal Supplement Series, Vol. 117

Speaker: Maria Angela Corazzi (Istituto Nazionale di Astrofisica (INAF))
• 1:35 PM
Lunch
• 23
Synthesis of Complex Organic Molecules (COMs) by ion-neutral reactions: from interstellar space to planetary atmosphere

Introduction: While being less abundant, and hence more difficult to detect with respect to neutrals, molecular ions play a key role in the interstellar medium (ISM) and planetary atmospheres, as intermediate steps in the build-up of complex organic molecules (COMs). For instance, the dissociative recombination of C2NH2+ is crucial to link methanimine and ammonia (Yuen et al. 2019) in both star forming regions and Titan’s atmosphere. Several charged species with a prebiotic potential, e.g. H2COH+ (Bacman et al. 2016), H2NCO+ (Marcelino et al. 2018), HNCCN+ (Rivilla et al. 2019) have been observed in pre-/protostellar regions. In the Solar System, the Cassini-Huygens mission detected a multitude of N-containing organic cations with unexpected abundances in Titan’s ionosphere and the idea has been put forward (Vuitton et al. 2019 and references therein; Hörst 2017) that ions trigger a rich gas-phase chemistry leading to the build-up of complex N-compounds, eventually forming tholins, a key ingredient of Titan’s haze.
Despite the ground-breaking discoveries made by space missions and astronomical observations, some questions are still open: what are the molecular structures of the ions? what are the chemical pathways responsible for the growth of complex ions? It is therefore necessary to investigate and quantify possible formation and destruction pathways of these species by measuring rate constants and branching ratios (BRs) of ionic reactions under laboratory conditions (pressure, temperature) close to those occurring in the ISM and planetary atmospheres.

Experiments & theory: Ion traps and guided beam devices have been employed to investigate ion-neutral processes. Recently, laboratory measurements of the reactions of different isomers of the cyanomethyl cation (c-C2H2N+ and CH2CN+) with several saturated and unsaturated hydrocarbons were performed using guided ion beam mass spectrometric techniques at Trento and Orsay. Photoionization of apt neutral precursors with tuneable VUV radiation from the DESIRS beamline @SOLEIL synchrotron radiation facility was used to ensure the production of specific isomers of the C2H2N+ ion (Fathi et al. 2016a, Fathi et al. 2016b, Fathi et al. 2016c).
Here we present new measurements on the generation of two different CH3N+ cation isomers, specifically the HCNH2+ (aminomethylenium ion) and the H2CNH+ (methyleniminium ion), using dissociative VUV photoionization of cyclopropylamine and azetidine neutrals, respectively. We have probed the reactivity of both isomers with small hydrocarbons (CH4, C2H2, C2H4, allene C3H4 ) and with CH3OH, both as a function of the photon and collision energy, in order to measure absolute reactive cross sections and product branching ratios. Ab initio calculations are performed in order to find reaction pathways leading to the observed products and to explain the dependence of their yield on the collision energy of the reactants.

Conclusions and outlook: Ion-neutral reactions like those investigated in the present study can lead to larger charged species, which upon subsequent neutralization processes, e.g. by dissociative recombination with electrons, can form heavy neutrals functioning as templates for reactions producing even larger species. Our results can help in improving the reliability of chemical models predicting the abundances and distributions of COMs in protoplanetary disks as well as in the atmospheres of planets and satellites.

References: Bacmann E. et al. 2016 A&A 588, L8; Fathi, P. et al. 2016a Molecular Astrophysics 5, 9; Fathi, P. et al. 2016b Molecular Astrophysics 2, 1; Fathi, P. et al. 2016c Int. J. Mass Spectrom. 411, 1; Hörst S. M. 2017 J. Geophys. Res. Planets 122, 432–482; Marcelino N. et al. 2018 A&A 612, L10; Rivilla V.M. et al. 2019 MNRAS Lett. 483, L114; Vuitton V. et al. (2019) Icarus 324, 120-197; Yuen C.H. et al. 2019 MNRAS 484, 659.

Speaker: Dr Daniela Ascenzi (Department of Physics, Università degli Studi di Trento)
• 24
How to measure spectra of planetary atmospheres in the laboratory ?

The habitability of (exo)planets depends on many factors, including the properties of the atmosphere. Spectra of planetary atmospheres are useful for the determination of the composition of the atmosphere, the detection of clouds, and the study of dynamical processes. Furthermore spectra taken in atmospheric transparency windows can shed light on low clouds and the surface of the planet.
The interpretation of spectral data requires accurate molecular constants for the species involved, as well as a theoretical comprehension of the phenomena contributing to the emission and absorption process occurring in various layers of the atmosphere. Although these data are available for the terrestrial atmosphere, the conditions in terms of density and temperature of many solar and extra solar planets are often very different from the Earth, and adequate data and theory are insufficient to describe emission and absorption processes properly.
Laboratory experiments can be useful to fill the gap in our knowledge and provide new spectral data that might also contribute to an improvement of theoretical models.
Here I will present some experimental techniques and recent laboratory measurements in conditions similar to the atmosphere of Venus.

Speaker: Marcel Snels (CNR)
• Exoplanets characterization
• 25
Exoplanet atmospheres at high spectral resolution

Two decades of discoveries have revealed in exquisite details the frequency and size of planets around other stars. And yet, their true nature and ability to support life still eludes our understanding. Solving the puzzle requires measuring the physical and chemical properties of exoplanet atmospheres, and enhancing our sensitivity to target temperate rocky planets.
High-resolution spectroscopy (R>25,000) has recently emerged as one of the leading methods to detect atomic and molecular species in the atmospheres of exoplanets. It allows us to resolve molecular bands into the individual spectral lines, and extract their signal through cross correlation with model templates. As an added bonus, it allows us to measure planet rotation and orbital motion directly. I will review the major breakthroughs achieved with this technique, and show how the unprecedented sensitivity of novel spectrographs and the imminent discovery of planets around bright stars by the TESS mission will revolutionise the field in the next few years. Once the next generation of extremely large telescopes will be online, high-resolution spectroscopy will allow us to target potentially habitable planets orbiting M-dwarf stars and hunt for signature of life on other worlds.

Speaker: Matteo Brogi (University of Warwick)
• 26
Exoplanetary characterisation with ARIEL

The ARIEL mission will be devoted to the observation of a large sample of (transiting) exo-planets with the goal to understand the properties of their atmospheres. Chemical composition, clouds, temperature profile, atmospheric circulation and the impact of stellar environment, among others, will be studied.
The observed sample will include gas giants, Neptunes, super-Earths and Earth-size planets orbiting around stars of different spectral type, focusing on warm and hot planets. These planets are particularly interesting since their atmospheres are well mixed, and, therefore, more representative of the planetary bulk compared to their colder counterparts.
ARIEL will observe simultaneously from 0.5 to 7.8 μm using photometry in the optical bands and low-resolution spectroscopy in the NIR. This broadband will cover several molecular features expected in the exo-atmospheres and will allow to monitor and correct for the stellar activity, the main source of astrophysical noise of exoplanet observations.

Speaker: Giuseppina Micela (Istituto Nazionale di Astrofisica (INAF))
• 27
The compositions of small planets with HARPS-N@TNG

Small ($R_{\rm p} < 3~R_\oplus$) exoplanets show an astonishing diversity in composition ranging from volatile-dominated to rocky Earth-like or iron-rich (Mercury-like) compositions. We have significantly contributed to unveil this diversity with the HARPS-N/GTO radial-velocity program aiming to measure accurate and precise masses/densities of Kepler, K2 and TESS small planets, which in turn allow to estimate the planet composition. First we will illustrate the properties of some of the most interesting Kepler/K2 exoplanets we have characterized with HARPS-N, then we will discuss the possible mechanisms that may shape the planet compositional properties and the crucial issues in the understanding of the origin of the composition diversity. The knowledge of interior compositions is also essential to select the small exoplanets most suitable for atmospheric characterization with future ground- and space-based facilities.

Speaker: Dr Aldo Stefano Bonomo (INAF - Osservatorio Astrofisico di Torino)
• 5:10 PM
Coffee break
• 5:30 PM
Discussion
• Wednesday, 23 October
• Exoplanets characterization
• 28
The visible arm of the GAPS 2.0 atmospheric characterization programme

I will present results obtained within the GAPS 2.0 long term programme for atmospheric characterization of hot giant planets using the Telescopio Nazionale Galileo (TNG) in the simultaneous GIARPS (GIANO-B + HARPS-N) observing mode. I will focus in particular on our ongoing efforts to probe exoplanetary atmospheres through transmission and emission spectroscopy using the visible light (380-690 nm) arm of GIARPS: the high-resolution (R ~ 116 000) spectrograph HARPS-N.

The vast majority of exoplanetary systems are completely different from our Solar System, and their orbital configurations challenge our traditional formation and migration theories. Crucial information about the environment where planets formed, their subsequent migration, and their interaction with the host star is somehow encoded in the present physical state and chemical composition of their atmospheres.

We are exploiting different tracers and analysis techniques in the GIARPS-VIS region to probe different atmospheric layers and physical mechanisms. This includes the study of metallic lines (such as the neutral Sodium doublet) and of the Balmer series to investigate evaporation processes and the dynamics of the upper atmosphere, and strong sources of optical opacities that regulate the whole energy balance of very hot Jupiters, such as TiO or atomic metals, that are found in their transmission and emission spectrum. I will review some of our preliminary results also in a wider context, since the refinement and development of our analysis techniques (including, for instance, telluric-correction algorithms) will be crucial for an optimal exploitation of forthcoming facilities such as E-ELT, able to probe smaller and more temperate planets.

Speaker: Nascimbeni Valerio (INAF-OAPD)
• 29
The near-infrared arm of the GAPS 2.0 atmospheric characterization programme

I will present results obtained within the GAPS 2.0 long term programme for atmospheric characterization of hot giant planets using the Telescopio Nazionale Galileo (TNG) in the simultaneous GIARPS (GIANO-B + HARPS-N) observing mode. I will focus in particular on our ongoing efforts to probe both the lower and the upper exoplanetary atmospheres using the near-infrared (0.95-2.45 \mu m) arm of GIARPS: the high-resolution (R /sim 50 000) spectrograph GIANO-B. On one hand, I will discuss our investigations of the deeper exo-atmospheric layers performed through the search of molecular species (e.g., water, methane, carbon dioxide, hydrogen cyanide) which, by constraining the planet’s C/O ratio, provide clear proxies on planetary formation. On the other hand, I will show our upper exoplanetary atmospheres’ analysis realized through the detection of the individual contributions of atoms (more precisely the metastable helium line at 1083.3 nm) in transiting Hot Jupiters’ transmission spectra. The helium line allows, in fact, not only a key insight into an exoplanetary exosphere, but also provides constraints on evolution processes (i.e. hydrodynamic escape, the mass loss rate, and the morphology of the escaping material).
Finally, I will outline some possible synergies between the GAPS 2.0 atmospheric characterization programme and future low-resolution space-based facilities (e.g. ARIEL, JWST). The combination of high- and low-resolution spectroscopy could, in fact, provide unique constraints on the exoplanetary atmospheres from the lower to the upper part.

Speaker: Gloria Guilluy (Istituto Nazionale di Astrofisica (INAF))
• 30
An ESPRESSO view of exoplanetary atmospheres

I will present new results obtained using the high-resolution ESPRESSO spectrograph by the GTO program for atmospheric characterization of exoplanets.
In particular, I will focus on the detection of atomic/molecular species and on their non-homogeneous distribution among the planetary surface.
The combination of the ESPRESSO performances with the VLT collecting area is opening a new window on exoplanetary atmospheres investigation.

Speaker: Francesco Borsa (Istituto Nazionale di Astrofisica (INAF))
• 31
Towards a comprehensive view of planet formation: The role of the host star's metallicity.

The role of the host star's metallicity in planet formation has been largely discussed in the framework of the so-called gas-giant/planet metallicity correlation. However, previous works are mainly focused on particular kinds of stars or planets. In this contribution we aim to put together all the pieces of the planet formation puzzle by analysing in the most homogeneous possible way a diverse sample of stars in terms of mass (from main sequence to giants) and spectral type (from M dwarfs to early-F) showing all the possible outcomes of the planet formation process (from planetesimals to brown dwarfs and low-mass binaries).

Speaker: Mr Jesus Maldonado (Istituto Nazionale di Astrofisica (INAF))
• 32
The chemical composition of young stars: implications for planet formation

In recent years a large number of studies have been devoted to chemically characterise open clusters, and stellar populations in general, in our Galaxy
and beyond (see e.g., the large spectroscopic surveys Gaia-ESO, GALAH, APOGEE, to name a fews). However, all these investigations focus on intermediate-age or old cluster (at least 600 Myr) and the chemical content of the very young population is mostly overlooked. There is debate in the literature as to whether star forming regions and young open clusters are more metal-poor than the Sun, which need to call for a peculiar Galactic chemical evolution. Crucially, this indication might suggest that these young environments are less favourable to form giant planets. We present in this contribution our very recent work that shows that analysis artefacts plague the previous conclusions, suggesting that young clusters and associations exhibit instead solar or super-solar chemical composition.

Speaker: Valentina D'Orazi (Istituto Nazionale di Astrofisica (INAF))
• 33
Connecting Habitability and Exoplanets Observables

The quantification of Planetary Habitability in terms of a number of Habitability indexes has been a main focus of many research efforts in the last decades. Those indexes have been correlated to variables such as the amount of insolation, the dry atmospheric pressure at ground, the chemical composition of atmosphere, etc. Often such studies do not give a direct relation between Habitability indexes and quantities which are easily measurable from astronomical observations such as: the differential extinction, the spectral extinction or the phase curves. This work is an attempt to connect Habitability indexes as defined in Silva et al. (2017), with a parameter more likely accessible for the observations, such as the number density of molecules projected on the stellar disk at transit or the depth of differential extinction introduced by the atmosphere.

Speaker: Dr Michele Maris (INAF/Trieste Astronomical Obsevatory)
• 12:00 PM
Concluding remarks