The Effect of Atmospheric Chemistry on the Optical Geometric Albedos of Hot Jupiters
Center for Space and Habitability, University of Bern（伯尔尼大学太空与宜居中心）；Space Telescope Science Institute（太空望远镜科学研究所）；Ludwig Maximilian University, University Observatory Munich（路德维希-马克西米利安大学慕尼黑天文台）；University of Warwick, Department of Physics, Astronomy & Astrophysics Group（华威大学物理、天文学与天体物理学组）；University of Bern, ARTORG Center for Biomedical Engineering Research（伯尔尼大学ARTORG生物医学工程研究中心）
K. D. Jones, B. M. Morris, K. Heng
备注：
14 pages, 10 figures, accepted for publication in A&A
We investigate the geometric albedos of hot Jupiters by comparing observational data from space telescopes TESS, Kepler, CoRoT, and CHEOPS against theoretical models. The study aims to understand the distribution of observed geometric albedos across different bandpasses and how these observations align with or deviate from model predictions. We have curated a comprehensive sample of observed geometric albedos, using either existing Spitzer secondary eclipse measurements or a scaling law between the equilibrium and dayside temperature to remove any contaminating thermal planetary emission. We then utilised hierarchical Bayesian modelling to identify trends with planetary properties such as equilibrium temperature, gravity, and stellar metallicity. On a population level, we found no statistical difference in the distributions of geometric albedos measured by TESS compared to those by Kepler, CoRoT and CHEOPS. We confront the geometric albedo sample with a simple, but first principles, model that includes Rayleigh scattering by molecular hydrogen and absorption by sodium, water and titanium oxide and vanadium oxide. We find that the abundance of sodium and water are the key absorbers that influence the geometric albedos of hot Jupiters, whilst the addition of titanium oxide and vanadium oxide (in the absence of condensation) results in vanishing geometric albedos that are inconsistent with the observed distributions.
We use ALMA measurements of 870 $μ$m thermal emission from a sample of mid-sized (15-40 km diameter) Jupiter Trojan asteroids to search for high albedo objects in this population. We calculate the diameters and albedos of each object using a thermal model which also incorporates {contemporaneous} Zwicky Transient Facility photometry to accurately measure the absolute magnitude at the time of the ALMA observation. We find that while many albedos are lower than reported from WISE, several small Trojans have high albedos independently measured both from ALMA and from WISE. The number of these hig…
Photometric observations of occultations of transiting exoplanets can place important constraints on the thermal emission and albedos of their atmospheres. We analyse photometric measurements and derive geometric albedo ($A_\mathrm{g}$) constraints for five hot Jupiters observed with TESS in the optical: WASP-18 b, WASP-36 b, WASP-43 b, WASP-50 b and WASP-51 b. For WASP-43 b, our results are complemented by a VLT/HAWK-I observation in the near-infrared at $2.09~μ$m. We derive the first geometric albedo constraints for WASP-50 b and WASP-51 b: $A_\mathrm{g}<0.445$ and $A_\mathrm{g}<0.368$, resp…
Optical secondary eclipse measurements made by \emph{Kepler} reveal a diverse set of geometric albedos for hot Jupiters with equilibrium temperatures between $1550-1700$ K. The presence or absence of high altitude condensates, such as Mg$_2$SiO$_4$, Fe, Al$_2$O$_3$, and TiO$_2$, can significantly alter optical albedos, but these clouds are expected to be confined to localized regions in the atmospheres of these tidally locked planets. Here, we present 3D general circulation models and corresponding cloud and albedo maps for six hot Jupiters with measured optical albedos in this temperature ran…
Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths to investigate these expectations. The NASA Kepler mission provides a means to widen the sample and to assess the extent to which hot Jupiter albedos are low. We present a global analysis of Kepler-7b based on Q0-Q4 data, published radial velocities, and asteroseismology constraints. We measure an occultation depth in the Kepler bandpass …
The depth of a secondary eclipse contains information of both the thermally emitted light component of a hot Jupiter and the reflected light component. If the dayside atmosphere of the planet is assumed to be isothermal, it is possible to disentangle both. In this work, we analyze 11 eclipse light curves of the hot Jupiter HAT-P-32b obtained at 0.89 $μ$m in the z' band. We obtain a null detection for the eclipse depth with state-of-the-art precision, -0.01 +- 0.10 ppt. We confirm previous studies showing that a non-inverted atmosphere model is in disagreement to the measured emission spectrum …
Reflected light curves observed for exoplanets indicate bright clouds at some of them. We estimate how the light curve and total stellar heating of a planet depend on forward and backward scattering in the clouds based on Pioneer and Cassini spacecraft images of Jupiter and Saturn. We fit analytical functions to the local reflected brightnesses of Jupiter and Saturn depending on the planet's phase. These observations cover broad bands at 0.59-0.72 and 0.39-0.5 μm, and narrow bands at 0.938 (atmospheric window), 0.889 (CH4 absorption band), and 0.24-0.28 μm. We simulate the images of the planet…
We report the discovery of a new hot-Jupiter, KOI-196b, transiting a solar-type star with an orbital period of 1.855558 days\pm0.6s thanks to public photometric data from the Kepler space mission and new radial velocity observations obtained by the SOPHIE spectrograph mounted on the 1.93-m telescope at the Observatoire de Haute-Provence, France. The planet KOI-196b, with a radius of 0.841\pm0.032 Rjup and a mass of 0.49\pm0.09 Mjup, orbits a G2V star with R* = 0.996\pm0.032 Rsun, M*= 0.94\pm0.09 Msun, [Fe/H] = -0.10\pm0.16 dex, Teff= 5660\pm100 K and an age of 7.7\pm3.4 Gy. KOI-196b is one the…
The largest and most close-in exoplanets would reflect enough star light to enable its ground-based photometric detection under the condition of a high to moderate albedo. We present the results of an observing campaign of secondary eclipse light curves of three of the most suitable exoplanet targets, WASP-43b, WASP-103b, and TrES-3b. The observations were conducted with meter-sized telescopes in the blue optical broadband filters Johnson B and Johnson V. We do not detect a photometric dimming at the moment of the eclipse, and derive a best-fit eclipse depth by an injection-recovery test. Thes…
Hilda asteroids and Jupiter Trojans are two low-albedo (p$_{\rm v}$ ~ 0.07) populations for which the Nice model predicts an origin in the primordial Kuiper Belt region. However, recent surveys by WISE and the Spitzer Space Telescope (SST) have revealed that ~2% of these objects possess high albedos (p$_{\rm v}$ > 0.15), which might indicate interlopers - that is, objects not formed in the Kuiper Belt - among these two populations. Here, we report spectroscopic observations in the visible and/or near-infrared spectral ranges of twelve high-albedo (p$_{\rm v}$ > 0.15) Hilda asteroids and Jupite…
We report the detection of the secondary eclipse of the hot Jupiter HD 209458b in optical/visible light using the CHEOPS space telescope. Our measurement of 20.4 +/- 3.3 ppm translates into a geometric albedo of A_g = 0.096 +/- 0.016. The previously estimated dayside temperature of about 1500 K implies that our geometric albedo measurement consists predominantly of reflected starlight and is largely uncontaminated by thermal emission. This makes the present result one of the most robust measurements of A_g for any exoplanet. Our calculations of the bandpass-integrated geometric albedo demonstr…
Thermal phase curves of short-period planets on circular orbits provide joint constraints on the fraction of incoming energy that is reflected (Bond albedo) and the fraction of absorbed energy radiated by the night hemisphere (heat recirculation efficiency). Many empirical studies of hot Jupiters have implicitly assumed that the dayside is the hottest hemisphere and the nightside is the coldest hemisphere. For a given eclipse depth and phase amplitude, an orbital lag between a planet's peak brightness and its eclipse---a phase offset---implies that planet's nightside emits greater flux. To qua…
We present an optical eclipse observation of the hot Jupiter WASP-12b using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. These spectra allow us to place an upper limit of $A_g < 0.064$ (97.5% confidence level) on the planet's white light geometric albedo across 290--570 nm. Using six wavelength bins across the same wavelength range also produces stringent limits on the geometric albedo for all bins. However, our uncertainties in eclipse depth are $\sim$40% greater than the Poisson limit and may be limited by the intrinsic variability of the Sun-like host star -…
It is challenging to measure the starlight reflected from exoplanets because of the extreme contrast with their host stars. For hot Jupiters, this contrast is in the range of $10^{-6}$ to $10^{-4}$, depending on their albedo, radius and orbital distance. Searches for reflected light have been performed since the first hot Jupiters were discovered, but with very limited success because hot Jupiters tend to have low albedo values due to the general absence of reflective cloud decks. The aim of this study is to search for reflected light from $τ$ Boo b, a hot Jupiter with one of the brightest hos…
Rotational spin-up due to outgassing of comet nuclei has been identified as a possible mechanism for considerable mass-loss and splitting. We report a search for spin changes for three large Jupiter-family comets (JFCs): 14P/Wolf, 143P/Kowal-Mrkos, and 162P/Siding Spring. None of the three comets has detectable period changes, and we set conservative upper limits of 4.2 (14P), 6.6 (143P) and 25 (162P) minutes per orbit. Comparing these results with all eight other JFCs with measured rotational changes, we deduce that none of the observed large JFCs experiences significant spin changes. This su…
Context. Measurements of the occultation of an exoplanet at visible wavelengths allow us to determine the reflective properties of a planetary atmosphere. The observed occultation depth can be translated into a geometric albedo. This in turn aids in characterising the structure and composition of an atmosphere by providing additional information on the wavelength-dependent reflective qualities of the aerosols in the atmosphere. Aims. Our aim is to provide a precise measurement of the geometric albedo of the gas giant HD 189733b by measuring the occultation depth in the broad optical bandpass o…
Inferences of molecular compositions of exoplanetary atmospheres have generally focused on C, H, and O-bearing molecules. Recently, additional absorption in HST WFC3 transmission spectra around 1.55$μ$m has been attributed to nitrogen-bearing chemical species: NH$_3$ or HCN. These species, if present in significant abundance, would be strong indicators of disequilibrium chemical processes -- e.g. vertical mixing and photochemistry. The derived N abundance, in turn, could also place important constraints on planetary formation mechanisms. Here, we examine the detectability of nitrogen chemistry…
We present results from a set of simulations using a fully coupled three-dimensional (3D) chemistry-radiation-hydrodynamics model and investigate the effect of transport of chemical species by the large-scale atmospheric flow in hot Jupiter atmospheres. We couple a flexible chemical kinetics scheme to the Met Office Unified Model which enables the study of the interaction of chemistry, radiative transfer and fluid dynamics. We use a newly-released "reduced" chemical network comprising 30 chemical species that has been specifically developed for application in 3D atmosphere models. We simulate …
First generation optical coronagraphic telescopes will obtain images of cool gas and ice giant exoplanets around nearby stars. The albedo spectra of exoplanets at planet-star separations larger than about 1 AU are dominated by reflected light to beyond 1 μm and are punctuated by molecular absorption features. We consider how exoplanet albedo spectra and colors vary as a function of planet-star separation, metallicity, mass, and observed phase for Jupiter and Neptune analogs from 0.35 to 1 μm. We model Jupiter analogs with 1x and 3x the solar abundance of heavy elements, and Neptune analogs wit…
We report new lightcurves and phase functions for nine Jupiter-family comets (JFCs). They were observed in the period 2004-2015 with various ground telescopes as part of the Survey of Ensemble Physical Properties of Cometary Nuclei (SEPPCoN) as well as during devoted observing campaigns. We add to this a review of the properties of 35 JFCs with previously published rotation properties. The photometric time-series were obtained in Bessel R, Harris R and SDSS r' filters and were absolutely calibrated using stars from the Pan-STARRS survey. This specially-developed method allowed us to combine da…
We present new optical and near-IR images of debris disk around the F-type star HD 114082. We obtained direct imaging observations and analysed the TESS photometric time series data of this target with a goal to search for planetary companions and to characterise the morphology of the debris disk and the scattering properties of dust particles. HD 114082 was observed with the VLT/SPHERE instrument: the IRDIS camera in the K band together with the IFS in the Y, J and H band using the ADI technique as well as IRDIS in the H band and ZIMPOL in the I_PRIME band using the PDI technique. The scatter…
On hot Jupiter exoplanets, strong horizontal and vertical winds should homogenize the abundances of the important absorbers CH$_4$ and CO much faster than chemical reactions restore chemical equilibrium. This effect, typically neglected in general circulation models (GCMs), has been suggested as explanation for discrepancies between observed infrared lightcurves and those predicted by GCMs: On the nightsides of several hot Jupiters, GCMs predict outgoing fluxes that are too large, especially in the Spitzer 4.5 $μ$m band. We modified the SPARC/MITgcm to include disequilibrium abundances of CH$_…
We present new grids of transmission spectra for hot-Jupiters by solving the multiple scattering radiative transfer equations with non-zero scattering albedo instead of using the Beer-Bouguer-Lambert law for the change in the transmitted stellar intensity. The diffused reflection and transmission due to scattering increases the transmitted stellar flux resulting into a decrease in the transmission depth. Thus we demonstrate that scattering plays a double role in determining the optical transmission spectra -- increasing the total optical depth of the medium and adding the diffused radiation du…
We study the distributions of effective diameter ($D$), beaming parameter ($η$), and visible geometric albedo ($p_V$) of asteroids in cometry orbits (ACOs) populations, derived from NASA's Wide-field Infrared Explorer (WISE) observations, and compare these with the same, independently determined properties of the comets. The near-Earth asteroid thermal model (NEATM) is used to compute the $D$, $p_V$ and $η$. We obtained $D$ and $p_V$ for 49 ACOs in Jupiter family cometary orbits (JF-ACOs) and 16 ACOs in Halley-type orbits (Damocloids). We also obtained $η$ for 45 of them. All but three JF-ACOs…
We present results from an atmospheric circulation study of nine hot Jupiters that comprise a large transmission spectral survey using the Hubble and Spitzer Space Telescopes. These observations exhibit a range of spectral behavior over optical and infrared wavelengths which suggest diverse cloud and haze properties in their atmospheres. By utilizing the specific system parameters for each planet, we naturally probe a wide phase space in planet radius, gravity, orbital period, and equilibrium temperature. First, we show that our model "grid" recovers trends shown in traditional parametric stud…
Exoplanet research focusing on the characterization of super-Earths is currently limited to those handful targets orbiting bright stars that are amenable to detailed study. This Letter proposes to look at alternative avenues to probe the surface and atmospheric properties of this category of planets, known to be ubiquitous in our galaxy. I conduct Markov Chain Monte Carlo lightcurve analyses for 97 Kepler close-in $R_P \lesssim 2.0 R_{\oplus}$ super-Earth candidates with the aim to detect their occultations at visible wavelengths. Brightness temperatures and geometric albedos in the Kepler ban…
We have conducted laboratory experiments to study the chemistry in hot Jupiter atmospheres with C/O ratio of 0.35. We have compared our results with the ones obtained previously for atmospheres with a C/O ratio of 1 to investigate the influence of the C/O ratio on the chemistry and formation of photochemical organic aerosol. We found that the C/O ratio and the gas mixture compositions strongly influence the pathways responsible for the formation of CO2. Thermochemical reactions are primarily responsible for the formation of CO2 in low C/O ratio atmospheres, while photochemistry is the dominant…
The elemental ratios of carbon, nitrogen, and oxygen in the atmospheres of hot Jupiters may hold clues to their formation locations in the protostellar disc. In this work, we adopt gas phase chemical abundances of C, N and O from several locations in a disc chemical kinetics model as sources for the envelope of the hot Jupiter HD 209458b and evolve the planet's atmospheric composition using a 1D chemical kinetics model, treating both vertical mixing and photochemistry. We consider two atmospheric pressure-temperature profiles, one with and one without a thermal inversion. From each of the resu…
We use a planetary albedo model to investigate variations in visible wavelength phase curves of exoplanets. The presence of clouds on these exoplanets significantly alters their planetary albedo spectra. We confirm that non-uniform cloud coverage on the dayside of tidally locked exoplanets will manifest as changes to the magnitude and shift of the phase curve. In this work, we first investigate a test case of our model using a Jupiter-like planet, at temperatures consistent to 2.0 AU insolation from a solar type star, to consider the effect of H2O clouds. We then extend our application of the …
KOI-13 was presented by the Kepler team as a candidate for having a giant planet - KOI-13.01, with orbital period of 1.7 d and transit depth of ~0.8%. We have analyzed the Kepler Q2 data of KOI-13, which was publicly available at the time of the submission of this paper, and derived the amplitudes of the beaming, ellipsoidal and reflection modulations: 8.6 +/- 1.1, 66.8 +/- 1.6 and 72.0 +/- 1.5 ppm (parts per million), respectively. After the paper was submitted, Q3 data were released, so we repeated the analysis with the newly available light curve. The results of the two quarters were quite …
We report the detection in Ks-band of the secondary eclipse of the hot Jupiter CoRoT-1b, from time series photometry with the ARC 3.5-m telescope at Apache Point Observatory. The eclipse shows a depth of 0.336+/-0.042 percent and is centered at phase 0.5022 (+0.0023,-0.0027), consistent with a zero eccentricity orbit ecosω = 0.0035 (+0.0036,-0.0042). We perform the first optical to near-infrared multi-band photometric analysis of an exoplanet's atmosphere and constrain the reflected and thermal emissions by combining our result with the recent 0.6, 0.71, and 2.09 micron secondary eclipse detec…
We report 78 secondary eclipse depths for a sample of 36 transiting hot Jupiters observed at 3.6- and 4.5 microns using the Spitzer Space Telescope. Our eclipse results for 27 of these planets are new, and include highly irradiated worlds such as KELT-7b, WASP-87b, WASP-76b, and WASP-64b, and important targets for JWST such as WASP-62b. We find that WASP-62b has a slightly eccentric orbit e cos(omega) = 0.00614+/- 0.00064, and we confirm the eccentricity of HAT-P-13b and WASP-14b. The remainder are individually consistent with circular orbits, but we find statistical evidence for eccentricity …
We present the most complete emission spectrum for inflated hot Jupiter HAT-P-41b combining new HST WFC/G141 spectrum from the Hubble Panchromatic Comparative Exoplanet Treasury (PanCET) program with archival Spitzer eclipse observations. We found a near blackbody-like emission spectrum which is best fitted with an isothermal temperature-pressure (TP) profile that agrees well with the dayside heat redistribution scenario assuming zero Bond albedo. The non-inverted TP profile is consistent with the non-detection of NUV/optical absorbers in the transit spectra. We do not find any evidence for si…
Polarimetry is a novel tool to detect and characterize exoplanets and their atmospheres. Polarized scattered light from the non-transiting hot Jupiter $\upsilon$~And~b is measured to further constrain its orbit, mass, density, and geometrical albedo. We obtained polarimetric measurements in the $UBV$ bands over the orbital period and deduce an average peak-to-peak amplitude of $(49 \pm 5)\times10^{-6}$ in both Stokes $q$ and $u$. From our data we evaluate the orbit inclination $i=111\degr\pm11\degr$, longitude of the ascending node $Ω=236\degr\pm12\degr$ (or equivalently 56\degr), the effectiv…
We investigate the effects of atmospheric circulation on the chemistry of the hot Jupiter HD 209458b. We use a simplified dynamical model and a robust chemical network, as opposed to previous studies which have used a three dimensional circulation model coupled to a simple chemical kinetics scheme. The temperature structure and distribution of the main atmospheric constituents are calculated in the limit of an atmosphere that rotates as a solid body with an equatorial rotation rate of 1 km/s. Such motion mimics a uniform zonal wind which resembles the equatorial superrotation structure found b…
Using the POLISH instrument, I am unable to reproduce the large-amplitude polarimetric observations of Berdyugina et al. (2008) to the >99.99% confidence level. I observe no significant polarimetric variability in the HD 189733 system, and the upper limit to variability from the exoplanet is Delta_P < 7.9 x 10^(-5) with 99% confidence in the 400 nm to 675 nm wavelength range. Berdyugina et al. (2008) report polarized, scattered light from the atmosphere of the HD 189733b hot Jupiter with an amplitude of two parts in 10^4. Such a large amplitude is over an order of magnitude larger than expecte…
We report on the detection of the secondary eclipse of the very-hot Jupiter OGLE-TR-56b from combined z-band time series photometry obtained with the VLT and Magellan telescopes. We measure a flux decrement of 0.0363+/-0.0091 percent from the combined Magellan and VLT datasets, which indicates a blackbody brightness temperature of 2718 (+127/-107) K, a very low albedo, and a small incident radiation redistribution factor, indicating a lack of strong winds in the planet's atmosphere. The measured secondary depth is consistent with thermal emission, but our precision is not sufficient to disting…
Modelling the effect of 3D temperature and chemistry on the cross-correlation signal of transiting ultra-hot Jupiters: A study of 5 chemical species on WASP-76b
WFIRST-CGI is a NASA technology demonstration mission that is charged with demonstrating key technologies for future exo-Earth imaging missions in space. In the process, it will obtain images and low-resolution spectra of a handful to a dozen extrasolar planets and possibly protoplanetary disks. Its unprecedented contrast levels in the optical will provide astronomers with their first direct look at mature, Jupiter sized planets at moderate separations. This paper addresses the question: what science can be done with such data? An analytic noise model, which is informed by the ongoing engineer…
The James Webb Space Telescope (JWST) is expected to revolutionize the field of exoplanets. The broad wavelength coverage and the high sensitivity of its instruments will allow characterization of exoplanetary atmospheres with unprecedented precision. Following the Call for the Cycle 1 Early Release Science Program, the Transiting Exoplanet Community was awarded time to observe several targets, including WASP-43b. The atmosphere of this hot Jupiter has been intensively observed but still harbors some mysteries, especially concerning the day-night temperature gradient, the efficiency of the atm…
We investigate the chemical composition of the solar system's giant planets atmospheres using a physical formation model with chemistry. The model incorporate disk evolution, pebbles and gas accretion, type I and II migration, simplified disk photoevaporation and solar system chemical measurements. We track the chemical compositions of the formed giant planets and compare them to the observed values. Two categories of models are studied: with and without disk chemical enrichment via photoevaporation. Predictions for the Oxygen and Nitrogen abundances, core masses, and total amount of heavy ele…
We present an updated cumulative size distribution (CSD) for Jupiter Family comet (JFC) nuclei, including a rigourous assessment of the uncertainty on the slope of the CSD. The CSD is expressed as a power law, N(>r_N) \propto r_N^{-q}, where r_N is the radius of the nuclei and q is the slope. We include a large number of optical observations published by ourselves and others since the comprehensive review in the "Comets II" book (Lamy et al. 2004), and make use of an improved fitting method. We assess the uncertainty on the CSD due to all of the unknowns and uncertainties involved (photometric…
[Abridged] Aims. We present a large atmospheric study of 49 gas giant exoplanets using infrared transmission photometry with Spitzer/IRAC at 3.6 and 4.5um. Methods. We uniformly analyze 70 photometric light curves of 33 transiting planets using our custom pipeline, which implements pixel level decorrelation. We use this survey to understand how infrared photometry traces changes in atmospheric chemical properties as a function of planetary temperature. We compare our measurements to a grid of 1D radiative-convective equilibrium forward atmospheric models which include disequilibrium chemistry.…
This paper reports the detection and the measurements of occultations of the two transiting hot giant exoplanets Kepler-5b and Kepler-6b by their parent stars. The observations are obtained in the near infrared with Spitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of constraining the eccentricities of these systems and of obtaining broad band emergent spectra for individual planets. For both targets, the occultations are detected at 3 sigma level at each wavelength with mid-occultation times consistent with circul…
In this work we investigate the impact of calculating non-equilibrium chemical abundances consistently with the temperature structure for the atmospheres of highly-irradiated, close-in gas giant exoplanets. Chemical kinetics models have been widely used in the literature to investigate the chemical compositions of hot Jupiter atmospheres which are expected to be driven away from chemical equilibrium via processes such as vertical mixing and photochemistry. All of these models have so far used pressure--temperature (P-T) profiles as fixed model input. This results in a decoupling of the chemist…
Due to its proximity to Earth, Jupiter of the Solar System serves as a unique case study for gas-giant exoplanets. In the current study, we perform fits of ab initio, reflective, semi-infinite, homogeneous model atmospheres to 61 phase curves from 0.40 to 1.00 $μ$m, obtained from the Cassini spacecraft, within a Bayesian framework. We reproduce the previous finding that atmospheric models using classic reflection laws (Lambertian, Rayleigh, single Henyey-Greenstein) provide poor fits to the data. Using the double Henyey-Greenstein reflection law, we extract posterior distributions of the singl…
From pre-transit to post-eclipse: investigating the impact of 3D temperature, chemistry, and dynamics on high-resolution emission spectra of the ultra-hot Jupiter WASP-76b
Institut Trottier de Recherche sur les Exoplanètes, Université de Montréal（特罗提尔系外行星研究所，蒙特利尔大学）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学，蔚蓝海岸天文台，法国国家科学研究中心，拉格朗日实验室）；Center for Space and Habitability, University of Bern（太空与宜居性中心，伯尔尼大学）
We present and validate a new network of atmospheric thermo-chemical and photo-chemical sulfur reactions. We use a 1-D chemical kinetics model to investigate these reactions as part of a broader HCNO chemical network in a series of hot and warm Jupiters. We find that temperatures approaching $1400\,\mathrm{K}$ are favourable for the production of H2S and HS around $\mathrm{10^{-3}\,bar}$, the atmospheric level where detection by transit spectroscopy may be possible, leading to mixing ratios of around $10^{-6}$. At lower temperatures, down to $1000\,\mathrm{K}$, the abundance of S2 can be up to…
In this work we study the effect of disequilibrium processes on mixing ratio profiles of neutral species and on the simulated spectra of a hot Jupiter exoplanet that orbits stars of different spectral types. We also address the impact of stellar activity that should be present to a different degree in all stars with convective envelopes. We used the VULCAN chemical kinetic code to compute number densities of species. The temperature-pressure profile of the atmosphere was computed with the HELIOS code. We also utilized the $τ$-ReX forward model to predict the spectra of planets in primary and s…
