Characterization of exoplanetary atmospheres through a model-unbiased spectral survey methodology

Context. Collecting a large variety of exoplanetary atmosphere measurements is crucial to improve our understanding of exoplanets. In this context, it is likely that the field would benefit from broad species surveys, particularly using transit spectroscopy, which is the most successful technique of exoplanetary atmosphere characterization so far. Aims. Our goal is to develop a model-unbiased technique using transit spectroscopy to analyze every qualified atomic spectral line in exoplanetary transit data, and search for relative absorption, that is, a decrease in the flux of the line when the planet is transiting. Methods. We analyzed archive data from HDS at Subaru, HIRES at Keck, UVES at VLT, and HARPS at LaSilla to test our spectral survey methodology. It first filtered individual lines by relative noise levels. It also corrected for spectral offsets and telluric contamination. Our methodology performed an analysis along time and wavelength. The latter employed a bootstrap corroboration. Results. We highlight the possible detections of Mn I and V II in HD 209459b data taken by HDS at Subaru (5.9σ at 5916.4 Å, 5.1σ at 6021.8 Å). The previous detection of Ca I in the same planet is classified as inconclusive by our algorithm, but we support the previous detection of Sc II (3.5σ at 6604.6 Å). We also highlight the possible detection of Ca I, Sc II, and Ti II in HD 189733 data taken by UVES at VLT (4.4σ at 6572.8 Å, 6.8σ at 6604.6 Å, and 3.5σ at 5910.1 Å), in addition to the possible detection of Al I in WASP-74b data taken by UVES at VLT (5.6σ at 6696.0 Å).

Charting nearby stellar systems: The intensity of Galactic cosmic rays for a sample of solar-type stars

<p>Galactic cosmic rays are important for exoplanetary atmospheres. They can contribute to the formation of hazes, prebiotic molecules and atmospheric electrical circuits. A number of so-called fingerprint ions, such as oxonium, have been identified from chemical modelling which are thought to be signatures of ionisation by energetic particles, such as Galactic cosmic rays. These fingerprint ions may be observed in exoplanetary atmospheres with upcoming JWST observations.</p> <p>I will discuss our recent results that model the propagation of Galactic cosmic rays through the stellar winds of a number of nearby solar-type stars. Our sample comprises of 5 well-observed solar-type stars that we have constructed well-constrained stellar wind models for. This allows us to calculate the transport of Galactic cosmic rays through these systems. I will present our results of the Galactic cosmic ray fluxes that reach (a) the habitable zone and (b) the location of known exoplanets. The systems show a variety of behaviour and I will discuss the most promising systems for upcoming JWST observations. </p>

Ariel - The ESA M4 Space Mission to Focus on the Nature Of Exoplanets

<p>Ariel, the atmospheric remote-sensing infrared exoplanet large-survey, is the recently adopted M4 mission within the Cosmic Vision science programme of ESA. The goal of Ariel is to investigate the atmospheres of planets orbiting distant stars in order to address the fundamental questions on how planetary systems form and evolve and to investigate in unprecedented detail the composition of a large number of exoplanetary atmospheres. During its 4-year mission, Ariel will observe hundreds of exoplanets ranging from Jupiter- and Neptune-size down to super-Earth size, in a wide variety of environments, in the visible and the infrared. The main focus of the mission will be on warm and hot planets in orbits close to their star. Some of the planets may be in the habitable zones of their stars, however. The analysis of Ariel spectra and photometric data will allow to extract the chemical fingerprints of gases and condensates in the planets’ atmospheres, including the elemental composition for the most favourable targets. The Ariel mission has been developed by a consortium of more than 60 institutes from 15 ESA member state countries, including UK, France, Italy, Poland, Spain, the Netherlands, Belgium, Austria, Denmark, Ireland, Hungary, Sweden, Czech Republic, Germany, Portugal, with an additional contribution from NASA. In this talk, we will review the science goals of the mission and give insight into the current status, both from the ESA and the Ariel Mission Consortium point of view.  </p>

TauREx 2D: Modelling 2D effects in retrievals

<div data-canvas-width="636.8035259153738">New-generation spectrographs dedicated to the study of exoplanetary atmospheres, require a higher precision in the atmospheric</div> <div data-canvas-width="636.8035259153735">models to better interpret the new spectra. Thanks to future space missions like JWST, ARIEL and Twinkle, indeed, the observed</div> <div data-canvas-width="636.8035259153738">spectra will be precise enough to reveal features which cannot be modeled with a one-dimensional plane parallel atmosphere,</div> <div data-canvas-width="636.8035259153739">especially in the case of Ultra Hot Jupiters. Bayesian frameworks are computationally intensive and prevent us from using complete</div> <div data-canvas-width="636.803525915374">three-dimensional self-consistent models to retrieve an exoplanetary atmosphere, and, they constrain us to use simplified models to</div> <div data-canvas-width="636.8035259153739">converge to a set of atmospheric parameters. We propose the TauREx2D retrieval code, which uses two-dimensional atmospheric</div> <div data-canvas-width="636.8035259153738">models as a good compromise between computational power and model precision to better infer exoplanetary atmospheres. Finally,</div> <div data-canvas-width="636.8035259153736">we apply such a model on synthetic spectrum computed from a GCM simulation of WASP121b and show the parameters retrieved by</div> <div data-canvas-width="167.95345291125463">the new TauREx 2D retrieval code.</div>

High-Resolution Infrared Spectroscopy of DC3N in the Stretching Region

The perspectives opened by modern ground-based infrared facilities and the forthcoming James Webb Telescope mission have brought a great attention to the ro-vibrational spectra of simple interstellar molecules. In this view, and because of the lack of accurate spectroscopic data, we have investigated the infrared spectrum of deuterated cyanoacetylene (DC3N), a relevant astrochemical species. The ν1, ν2, and ν3 fundamentals as well as their hot-bands were observed in the stretching region (1,500–3,500 cm−1) by means of a Fourier transform infrared spectrometer. Supplementary measurements were performed at millimeter-wavelengths (243–295 GHz) with a frequency-modulation spectrometer equipped with a furnace, that allowed to probe pure rotational transitions in the investigated stretching states. Furthermore, since HC3N is observed as by-product in our spectra and suffers from the same deficiency of accurate infrared data, its ro-vibrational features have been analyzed as well. The combined analysis of both rotational and ro-vibrational data allowed us to determine precise spectroscopic constants that can be used to model the infrared spectra of DC3N and HC3N. The importance of accurate molecular data for the correct modeling of proto-planetary disks and exoplanetary atmospheres is then discussed.