The 2020 release of the ExoMol database: molecular line lists for exoplanet and other hot atmospheres
Jonathan Tennyson, Sergei N. Yurchenko, Ahmed F. Al-Refaie, Victoria H. J. Clark, Katy L. Chubb, Eamon K. Conway, Akhil Dewan, Maire N. Gorman, Christian Hill, … 展开作者
Jonathan Tennyson, Sergei N. Yurchenko, Ahmed F. Al-Refaie, Victoria H. J. Clark, Katy L. Chubb, Eamon K. Conway, Akhil Dewan, Maire N. Gorman, Christian Hill, A. E. Lynas-Gray, Thomas Mellor, Laura K. McKemmish, Alec Owens, Oleg L. Polyansky, Mikhail Semenov, Wilfrid Somogyi, Giovanna Tinetti, Apoorva Upadhyay, Ingo Waldmann, Yixin Wang, Samuel Wright, Olga P. Yurchenko
发表信息：
J. Quant. Spectrosc. Rad. Transf., 255, 107228 (2020)
The ExoMol database (www.exomol.com) provides molecular data for spectroscopic studies of hot atmospheres. While the data is intended for studies of exoplanets and other astronomical bodies, the dataset is widely applicable. The basic form of the database is extensive line lists; these are supplemented with partition functions, state lifetimes, cooling functions, Landé g-factors, temperature-dependent cross sections, opacities, pressure broadening parameters, $k$-coefficients and dipoles. This paper presents the latest release of the database which has been expanded to consider 80 molecules and 190 isotopologues totaling over 700 billion transitions. While the spectroscopic data is concentrated at infrared and visible wavelengths, ultraviolet transitions are being increasingly considered in response to requests from observers. The core of the database comes from the ExoMol project which primarily uses theoretical methods, albeit usually fine-tuned to reproduce laboratory spectra, to generate very extensive line lists for studies of hot bodies. The data has recently been supplemented by line lists deriving from direct laboratory observations, albeit usually with the use of ab initio transition intensities. A major push in the new release is towards accurate characterisation of transition frequencies for use in high resolution studies of exoplanets and other bodies.
The ExoMol database aims to provide comprehensive molecular line lists for exoplanetary and other hot atmospheres. The data are expanded by inclusion of empirically derived line lists taken from the literature for a series of diatomic molecules, namely CH, NH, OH, AlCl, AlF, OH$^+$, CaF, MgF, KF, NaF, LiCl, LiF, MgH, TiH, CrH, FeH, C$_2$, CP, CN, CaH, and triplet N$_2$. Generally, these line lists are constructed from measured spectra using a combination of effective rotational Hamiltonian models for the line positions and ab initio (transition) dipole moments to provide intensities. This work…
The ExoMol project is dedicated to providing molecular line lists for exoplanet and other hot atmospheres. The ExoMol procedure uses a mixture of ab initio calculations and available laboratory data. The actual line lists are generated using variational nuclear motion calculations. These line lists form the input for opacity models for cool stars and brown dwarfs as well as for radiative transport models involving exoplanets. This paper is a collection of molecular opacities for 52 molecules (130 isotopologues) at two reference temperatures, 300 K and 2000 K, using line lists from the ExoMol d…
Potassium hydroxide (KOH) and sodium hydroxide (NaOH) are expected to occur in the atmospheres of hot rocky super-Earth exoplanets but a lack of spectroscopic data is hampering their potential detection. Using robust first-principles methodologies, comprehensive molecular line lists for KOH and NaOH that are applicable for temperatures up to $T=3500$ K are presented. The KOH OYT4 line list covers the 0-6000 cm$^{-1}$ (wavelengths $λ> 1.67$ $μ$m) range and comprises 38 billion transitions between 7.3 million energy levels with rotational excitation up to $J=255$. The NaOH OYT5 line list covers …
A new line list for H$_2$$^{16}$O is presented. This line list, which is called POKAZATEL, includes transitions between rotation-vibrational energy levels up to 41000 cm$^{-1}$ in energy and is the most complete to date. The potential energy surface (PES) used for producing the line list was obtained by fitting a high-quality ab initio PES to experimental energy levels with energies of 41000 cm$^{-1}$ and for rotational excitations up to $J=5$. The final line list comprises all energy levels up to 41000 cm$^{-1}$ and rotational angular momentum $J$ up to 72. An accurate ab initio dipole moment…
A new line list for AlH is produced. The WYLLoT line list spans two electronic states $X\,{}^1Σ^+$ and $A\,{}^1Π$. A diabatic model is used to model the shallow potential energy curve of the $A\,{}^1Π$ state, which has a strong pre-dissociative character with only two bound vibrational states. Both potential energy curves are empirical and were obtained by fitting to experimentally derived energies of the $X\,{}^1Σ^+$ and $A\,{}^1Π$ electronic states using the diatomic nuclear motion codes Level and Duo. High temperature line lists plus partition functions and lifetimes for three isotopologues…
A new hot line list for the main isotopologue of CO$_2$ is presented. The line list consists of almost 2.5 billion transitions between 3.5 million rotation-vibration states of CO$_2$ in its ground electronic state, covering the wavenumber range 0-20000 cm$^{-1}$ ($λ>0.5$ $μ$m) with the upper and lower energy thresholds of 36 000 cm$^{-1}$ and 16 000 cm$^{-1}$, respectively. The ro-vibrational energies and wavefunctions are computed variationally using the Ames-2 accurate empirical potential energy surface. The ro-vibrational transition probabilities in the form of Einstein coefficients are com…
A new hot line list for $^{14}$NH$_3$ is presented. The line list CoYuTe was constructed using an accurate, empirically refined potential energy surface and a CCSD(T)/aug-cc-pVQZ ab initio dipole moment surface of ammonia, previously reported. The line list is an improvement of the ammonia line list BYTe [Yurchenko et al., Mon. Not. R. Astron. Soc., 413, 1828 (2011)]. The CoYuTe line list covers wavenumbers up to 20000 cm$^{-1}$, i.e. wavelengths beyond 0.5 $μ$m for temperatures up to 1500 K. Comparisons with the high temperature experimental data from the literature show excellent agrement fo…
H$_3^+$ is a ubiquitous and important astronomical species whose spectrum has been observed in the interstellar medium, planets and tentatively in the remnants of supernova SN1897a. Its role as a cooler is important for gas giant planets and exoplanets, and possibly the early Universe. All this makes the spectral properties, cooling function and partition function of H$_3^+$ key parameters for astronomical models and analysis. A new high-accuracy, very extensive line list for H$_3^+$ called MiZATeP was computed as part of the ExoMol project alongside a temperature-dependent cooling function an…
A new line list for hydronium (H$_3$$^{16}$O$^+$) is computed. The line list is based on a new ab initio dipole moment surface (CCSD(T)/aug-cc-pVQZ) and a new empirical potential energy surface (PES). The empirical PES of H$_3$O$^+$ was obtained by refining an ab initio surface through a global fit to the experimentally determined ro-vibrational energies collected from the literature covering the ground, $ν_1^{\pm}$, $ν_2^{\pm}$, $2ν_2^{\pm}$, $ν_3^{\pm}$ and $ν_4^{\pm}$ vibrational states. The line list covers the wavenumber range up to 10 000 cm$^{-1}$ (wavelengths $>1 μ$m) and should be com…
The discovery of extrasolar planets is one of the major scientific advances of the last two decades. Hundreds of planets have now been detected and astronomers are beginning to characterise their composition and physical characteristics. To do this requires a huge quantity of spectroscopic data most of which is not available from laboratory studies. The ExoMol project will offer a comprehensive solution to this problem by providing spectroscopic data on all the molecular transitions of importance in the atmospheres of exoplanets. These data will be widely applicable to other problems and will …
SiH has long been observed in the spectrum of our Sun and other cool stars. Computed line lists for the main isotopologues of silicon monohydride, $^{28}$SiH, $^{29}$SiH, $^{30}$SiH and $^{28}$SiD are presented. These line lists consider rotation-vibration transitions within the ground $X$ $^{2}Π$ electronic state as well as transitions to the low-lying $A$ $^{2}Δ$ and $a$ $^{4}Σ^-$ states. Ab initio potential energy (PECs) and dipole moment curves (DMCs) along with spin-orbit and electronic-angular-momentum couplings between them are calculated using the MRCI level of theory with the MOLPRO p…
A variationally computed $^{28}$SiH$_4$ rotation-vibration line list applicable for temperatures up to $T=1200\,$K is presented. The line list, called OY2T, considers transitions with rotational excitation up to $J=42$ in the wavenumber range $0$--$5000\,$cm$^{-1}$ (wavelengths $λ> 2\,μ$m). Just under 62.7 billion transitions have been calculated between 6.1 million energy levels. Rovibrational calculations have utilized a new `spectroscopic' potential energy surface determined by empirical refinement to 1452 experimentally derived energy levels up to $J=6$, and a previously reported \textit{a…
A publicly available database of opacities for molecules of astrophysical interest, ExoMolOP, has been compiled for over 80 species, based on the latest line list data from the ExoMol, HITEMP and MoLLIST databases. These data are generally suitable for characterising high temperature exoplanet or cool stellar/substellar atmospheres, and have been computed at a variety of pressures and temperatures, with a few molecules included at room-temperature only from the HITRAN database. The data are formatted in different ways for four different exoplanet atmosphere retrieval codes; ARCiS, TauREx, NEME…
Accurate line lists for the carbon dimer, C$_2$, are presented. These line lists cover rovibronic transitions between the eight lowest electronic states: $X\,{}^{1}Σ_{g}^{+}$, $a\,{}^{3}Π_{u}$, $A\,{}^{1}Π_{u}$, $b\,^{3}Σ_{g}^{-}$, $b\,^{3}Σ_{g}^{-}$, $c\,^{3}Σ_{u}^{+}$, $d\,{}^{3}Π_{g}$, $B\,{}^{1}Δ_{g}$, $B^\prime\,{}^{1}Σ_{g}^{+}$. Potential energy curves (PECs) and transition dipole moment curves are computed on a large grid of geometries using the aug-cc-pwCVQZ-DK/MRCI level of theory including core and core-valence correlations and scalar relativistic energy corrections. The same level o…
SiS has long been observed in the circumstellar medium of the carbon-rich star IRC+10216 CW Leo. Comprehensive and accurate rotation-vibrational line lists and partition functions are computed for 12 isotopologues of silicon sulphide ($^{28}$Si$^{32}$S, $^{28}$Si$^{34}$S, $^{29}$Si$^{32}$S, $^{28}$Si$^{33}$S, $^{30}$Si$^{32}$S, $^{29}$Si$^{34}$S, $^{30}$Si$^{34}$S, $^{28}$Si$^{36}$S, $^{29}$Si$^{33}$S, $^{29}$Si$^{36}$S, $^{30}$Si$^{33}$S, $^{30}$Si$^{36}$S) in its ground (X $^1Σ^+$) electronic state. The calculations employ an existing spectroscopically accurate potential energy curve (PEC) d…
A rovibronic line list for the ground ($X$ $^3Σ^-$) and first excited ($a$ $^1Δ$) states of phosphinidene, $^{31}$PH, is computed. The line list is designed for studies of exoplanetary and cool stellar atmospheres with temperatures up to 4000 K. A combination of empirical and ab initio data are used to produce the line list: potential energy curves (PECs) are fitted using experimental transition frequencies; these transitions are reproduced with a root mean square error of 0.01 cm$^{-1}$. The nuclear Schrödinger is solved using these PECs plus Born-Oppenheimer and spin splitting correction ter…
Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its presence is often associated with volcanism, and in circumstellar envelopes of young and evolved stars as well as the interstellar medium. This work presents a line list of 1.3 billion $^{32}$S$^{16}$O$_2$ vibration-rotation transitions computed using an empirically-adjusted potential energy surface and an ab initio dipole moment surface. The list gives complete coverage up to 8000 cm$^{-1}$ (wavelengths longer than 1.25 $μ$m) for temperatures below 2000 K. Infrared absorption cross sections are recorded at 3…
A new silicon monoxide ($^{28}$Si$^{16}$O) line list covering infrared, visible and ultraviolet regions called SiOUVenIR is presented. This line list extends the infrared EBJT ExoMol line list by including vibronic transitions to the $A\,{}^{1}Π$ and $E\,{}^{1}Σ^{+}$ electronic states. Strong perturbations to the $A\,{}^{1}Π$ band system are accurately modelled through the treatment of 6 dark electronic states: $C\,{}^{1}Σ^{-}$, $D\,{}^{1}Δ$, $a\,{}^{3}Σ^{+}$, $b\,{}^{3}Π$, $e\,{}^{3}Σ^{-}$ and $d\,{}^{3}Δ$. Along with the $X\,{}^{1}Σ^{+}$ ground state, these 9 electronic states were used to b…
A new ro-vibrational line list for the ground electronic state of the main isotopologue of acetylene, $^{12}$C$_2$H$_2$, is computed as part of the ExoMol project. The aCeTY line list covers the transition wavenumbers up to 10,000 cm$^{-1}$ ($ λ>1$ $μ$m), with lower and upper energy levels up to 12,000 cm$^{-1}$ and 22,000 cm$^{-1}$ considered, respectively. The calculations are performed up to a maximum value for the vibrational angular momentum, $K_{\rm max}=L_{\rm max}$ = 16, and maximum rotational angular momentum, $J$ = 99. Higher values of $J$ were not within the specified wavenumber win…
Accurate rotation-vibration line lists are calculated for silicon monoxide. Line lists are presented for the main isotopologue, $^{28}$Si$^{16}$O, and for four monosubsituted isotopologues ($^{29}$Si$^{16}$O, $^{30}$Si$^{16}$O, $^{28}$Si$^{18}$O and $^{28}$Si$^{17}$O), in their ground electronic states. These line lists are suitable for high temperatures (up to 9000 K) including those relevant to exoplanetary atmospheres and cool stars. A combination of empirical and \textit{ab initio} methods is used: the potential energy curves are determined to high accuracy by fitting to extensive data fro…
An accurate line list, VOMYT, of spectroscopic transitions is presented for hot VO. The 13 lowest electronic states are considered. Curves and couplings are based on initial {\it ab initio} electronic structure calculations and then tuned using available experimental data. Dipole moment curves, used to obtain transition intensities, are computed using high levels of theory (e.g. MRCI/aug-cc-pVQZ using state-specific or minimal-state CAS for dipole moments). This line list contains over 277 million transitions between almost 640,000 energy levels. It covers the wavelengths longer than 0.29 $μ$m…
Line lists for the sulphur-containing molecules SH (the mercapto radical) and NS are computed as part of the ExoMol project. These line lists consider transitions within the $X$ ${}^2Π$ ground state for $^{32}$SH, $^{33}$SH, $^{34}$SH and $^{\text{32}}$SD, and $^{14}$N$^{32}$S, $^{14}$N$^{33}$S, $^{14}$N$^{34}$S, $^{14}$N$^{36}$S and $^{15}$N$^{32}$S. Ab initio potential energy (PEC) and spin-orbit coupling (SOC) curves are computed and then improved by fitting to experimentally observed transitions. Fully ab initio dipole moment curves (DMCs) computed at high level of theory are used to produ…
A new hot line list is calculated for $^{12}$CH$_4$ in its ground electronic state. This line list, called 10to10, contains 9.8 billion transitions and should be complete for temperatures up to 1500 K. It covers the wavelengths longer than 1 $μ$m and includes all transitions to upper states with energies below $hc \cdot 18\,000$ cm$^{-1}$ and rotational excitation up to $J=39$. The line list is computed using the eigenvalues and eigenfunctions of CH$_4$ obtained by variational solution of the Schrödinger equation for the rotation-vibration motion of nuclei employing program TROVE. An ab initio…
Nitric acid is a possible biomarker in the atmospheres of exoplanets. An accurate line list of rotational and rotational-vibrational transitions is computed for nitric acid (HNO$_3$). This line list covers wavelengths longer than 1.42 $μ$m (0 - 7000 cm$^{-1}$) and temperatures up to 500 K. The line list is computed using a hybrid variational -- perturbation theory and empirically tuned potential energy and dipole surfaces. It comprises almost 7 billion transitions involving rotations up to $J=100$. Comparisons with spectra from the HITRAN and PNNL databases demonstrate the accuracy of our calc…
Accurate line lists are calculated for aluminium monoxide covering the pure rotation, rotation-vibration and electronic (B -- X blue-green and A -- X infrared bands) spectrum. Line lists are presented for the main isotopologue, $^{27}$Al$^{16}$O, as well as for $^{27}$Al$^{17}$O, $^{27}$Al$^{18}$O and $^{26}$Al$^{16}$O. These line lists are suitable for high temperatures (up to 8000 K) including those relevant to exoplanetary atmospheres and cool stars. A combination of empirical and \textit{ab initio} methods is used: the potential energy curves were previously determined to high accuracy by …
A hybrid approach to generating diatomic line lists for high resolution studies of exoplanets and other hot astronomical objects: Updates to ExoMol MgO, TiO and VO line lists
A revised rotation-vibration line list for the combined hydrogen cyanide (HCN) / hydrogen isocyanide (HNC) system is presented. The line list uses {\it ab initio} transition intensities calculated previously (Harris et al., ApJ, 2002, 578, 657) and extensive datasets of recently measured experimental energy levels (Mellau, J. Chem. Phys. and J. Mol. Spectrosc. 2010-2011). The resulting line list has significantly more accurate wavelengths than previous ones for these systems. An improved value for the separation between HCN and HNC is adopted leading to an approximately 25%\ lower predicted th…
Any future detection of the calcium monohydroxide radical (CaOH) in stellar and exoplanetary atmospheres will rely on accurate molecular opacity data. Here, we present the first comprehensive molecular line list of CaOH covering the \A--\X\ rotation-vibration-electronic and \X--\X\ rotation-vibration bands. The newly computed OYT6 line list contains over 24.2 billion transitions between 3.2 million energy levels with rotational excitation up to $J=175.5$. It is applicable to temperatures up to $T=3000$~K and covers the 0\,--\,35\,000~cm$^{-1}$ range (wavelengths $λ> 0.29$~$μ$m) for rotational,…
Comprehensive line lists for phosphorus monoxide ($^{31}$P$^{16}$O) and phosphorus monosulphide ($^{31}$P$^{32}$S) in their $X$ $^2Π$ electronic ground state are presented. The line lists are based on new ab initio potential energy (PEC), spin-orbit (SOC) and dipole moment (DMC) curves computed using the MRCI+Q-r method with aug-cc-pwCV5Z and aug-cc-pV5Z basis sets. The nuclear motion equations (i.e. the rovibronic Schrödinger equations for each molecule) are solved using the program Duo. The PECs and SOCs are refined in least-squares fits to available experimental data. Partition functions, $…
Line lists for magnesium oxide are computed and extensive comparisons are made with existing experimental spectra. The LiTY line lists cover all ro-vibration transitions within the five lowest-lying electronic states ($X\,{}^1Σ^+$, $a\,{}^3Π$, $A\,{}^1Π$, $B\,{}^1Σ^+$ and $b\,{}^3Σ^{+}$) and five isotopologues: $^{24}$Mg$^{16}$O, $^{25}$Mg$^{16}$O, $^{26}$Mg$^{16}$O, $^{24}$Mg$^{17}$O, $^{24}$Mg$^{18}$O, $^{24}$Mg$^{17}$O and $^{24}$Mg$^{18}$O. The calculation use potential energy cures, spin-orbit and electronic angular momentum couplings curves determined by fitting to empirical energy level…
A new line list for ethylene, $^{12}$C$_2$$^1$H$_4$ is presented. The line list is based on high level ab initio potential energy and dipole moment surfaces. The potential energy surface is refined by fitting to experimental energies. The line list covers the range up to 7000 cm$^{-1}$ (1.43 $μ$m) with all ro-vibrational transitions (50 billion) with the lower state below 5000 cm$^{-1}$ included and thus should be applicable for temperatures up to 700 K. A technique for computing molecular opacities from vibrational band intensities is proposed and used to provide temperature dependent cross s…
New molecular line lists for calcium monohydride ($^{40}$Ca$^{1}$H) and magnesium monohydride ($^{24}$Mg$^{1}$H) and its minor isotopologues ($^{25}$Mg$^{1}$H and $^{26}$Mg$^{1}$H) are presented. The rotation-vibration-electronic (rovibronic) line lists, named \texttt{XAB}, consider transitions involving the \X, \A, and \BBp\ electronic states in the 0--30\,000~cm$^{-1}$ region (wavelengths $λ> 0.33$~$μ$m) and are suitable for temperatures up to 5000 K. A comprehensive analysis of the published spectroscopic literature on CaH and MgH is used to obtain new extensive datasets of accurate rovibro…
Accurate rotation-vibration line lists for two molecules, NaCl and KCl, in their ground electronic states are presented. These line lists are suitable for temperatures relevant to exoplanetary atmospheres and cool stars (up to 3000 K). Isotopologues $^{23}$Na$^{35}$Cl, $^{23}$Na$^{37}$Cl, $^{39}$K$^{35}$Cl, $^{39}$K$^{37}$Cl, $^{41}$K$^{35}$Cl and $^{41}$K$^{37}$Cl are considered. Laboratory data was used to refine ab initio potential energy curves in order to compute accurate ro-vibrational energy levels. Einstein A coefficients are generated using newly determined ab initio dipole moment cur…
Accurate line lists are crucial for correctly modelling a variety of astrophysical phenomena, including stellar photospheres and the atmospheres of extra-solar planets. This paper presents a new line database Toto for the main isotopologues of titanium oxide (TiO): $^{46}$Ti$^{16}$O, $^{47}$Ti$^{16}$O, $^{48}$Ti$^{16}$O, $^{49}$Ti$^{16}$O and $^{50}$Ti$^{16}$O. The TiO line list contains transitions with wave-numbers up to 30,000 cm$^{-1}$ ie long-wards of 0.33 $μ$m. The Toto line list includes all dipole-allowed transitions between 13 low-lying electronic states (X $^3Δ$, a $^1Δ$, d $^1Σ^+$, …
The spectrum of dicarbon (C2) is important in astrophysics and for spectroscopic studies of plasmas and flames. The C2 spectrum is characterized by many band systems with new ones still being actively identified; astronomical observations involve eight of these bands. Recently, Furtenbacher et al. (2016, Astrophys. J. Suppl., 224, 44) presented a set of 5699 empirical energy levels for 12C2, distributed among 11 electronic states and 98 vibronic bands, derived from 42 experimental studies and obtained using the MARVEL (Measured Active Rotational-Vibrational Energy Levels) procedure. Here, we a…
ExoCross is a Fortran code for generating spectra (emission, absorption) and thermodynamic properties (partition function, specific heat etc.) from molecular line lists. Input is taken in several formats, including ExoMol and HITRAN formats. ExoCross is efficiently parallelized showing also a high degree of vectorization. It can work with several line profiles such as Doppler, Lorentzian and Voigt and support several broadening schemes. Voigt profiles are handled by several methods allowing fast and accurate simulations. Two of these methods are new. ExoCross is also capable of working with th…
Accurate line lists are important for the description of the spectroscopic nature of small molecules. While a line list for CN (an important molecule for chemistry and astrophysics) exists, no underlying energy spectroscopic model has been published, which is required to consider the sensitivity of transitions to a variation of the proton-to-electron mass ratio. Here we have developed a Duo energy spectroscopic model as well as a novel hybrid style line list for CN and its isotopologues, combining energy levels that are derived experimentally (Marvel), using the traditional/perturbative approa…
A rotation-vibration line list for the electronic ground state ($\tilde{X}^{1}A_{1}$) of SiH$_2$ is presented. The line list, named CATS, is suitable for temperatures up to 2000 K and covers the wavenumber range 0 - 10,000 cm$^{-1}$(wavelengths $>1.0$ $μ$m) for states with rotational excitation up to $J=52$. Over 310 million transitions between 593 804 energy levels have been computed variationally with a new empirically refined potential energy surface, determined by refining to 75 empirical term values with $J\leq 5$ and a newly computed high-level ab initio dipole moment surface. This is th…
The majority of stars are now thought to support exoplanets. Many of those exoplanets discovered thus far are categorized as rocky objects with an atmosphere. Most of these objects are however hot due to their short orbital period. Models suggest that water is the dominant species in their atmospheres. The hot temperatures are expected to turn these atmospheres into a (high pressure) steam bath containing remains of melted rock. The spectroscopy of these hot rocky objects will be very different from that of cooler objects or hot gas giants. Molecules suggested to be important for the spectrosc…
This study is based on the use of the new ExoMol TiO rovibronic line lists to identify and model TiO isotopologue features in spectra of M-dwarfs. We aim to investigate problems involving the computation of electronic bands for different isotopologues of TiO by modelling optical spectra of late-type stars and to determine their Ti isotopic abundances, to compare the TiO isotopologues spectra computed using line lists by different authors. We fit theoretical synthetic spectra to the observed stellar molecular bands of TiO. We model spectra of two M-dwarfs: GJ 15A (M1V) and GJ 15B (M3 V) to dete…
The recently-computed ExoMol line lists for isotopologues of AlH are used to analyse the blue spectrum (4000-4500 Å) of Proxima Cen (M5.5 V). Comparison of the observed and computed spectra enables the identification of a large number of 27AlH lines of the A1Π - X1Σ+ band system: the spectral range covering 1-0, 0-0 and 1-1 bands is dominated by clearly resolved AlH lines. We reveal the diffuse nature of transitions close to the dissociation limit which appears in the form of increasingly wider(up to 5 Å) and shallower (up to the continuum confusion limit) AlH line profiles. The predicted wave…
High-Resolution Spectroscopy (HRS) has been used to study the composition and dynamics of exoplanetary atmospheres. In particular, the spectrometer CRIRES installed on the ESO-VLT has been used to record high-resolution spectra in the Near-IR of gaseous exoplanets. Here we present a new automatic pipeline to analyze CRIRES data-sets. Said pipeline is based on a novel use of Principal Component Analysis (PCA) and Cross-Correlation Function (CCF). The exoplanetary atmosphere is modeled with the $τ$-REx code using opacities at high temperature from the ExoMol project. In this work, we tested our …
Published high-resolution rotation-vibration transitions of \spec{h212c16o}, the principal isotopologue of methanal, are analyzed using the MARVEL (Measured Active Rotation-Vibration Energy Levels) procedure. The literature results are augmented by new, high-accuracy measurements of pure rotational transitions within the ground, $ν_3$, $ν_4$, and $ν_6$ vibrational states. Of the \nbNonRedTr\ non-redundant transitions processed, which come from \nbSr\ sources including the present work, \nbValTr\ could be validated, providing \nbEl\ empirical energy levels of \spec{h212c16o}\ with statistically…
We present the STScI WFC3 project webpage, Transiting Exoplanets List of Space Telescope Spectroscopy, TrExoLiSTS. It tabulates existing observations of transiting exoplanet atmospheres, available in the MAST archive made with HST WFC3 using the stare or spatial scan mode. A parallel page is available for all instruments aboard JWST using the spectral Time Series Observation (TSO) mode. The web pages include observations obtained during primary transits, secondary eclipses and phase curves. TREXOLISTS facilitates proposal preparation for programs that are highly-complementary to existing progr…
Hot methane spectra are important in environments ranging from flames to the atmospheres of cool stars and exoplanets. A new spectroscopic line list, 10to10, for $^{12}$CH$_4$ containing almost 10 billion transitions is presented. This comprehensive line list covers a broad spectroscopic range and is applicable for temperatures up to 1 500 K. Previous methane data are incomplete leading to underestimated opacities at short wavelengths and elevated temperatures. Use of 10to10 in models of the bright T4.5 brown dwarf 2MASS 0559-14 leads to significantly better agreement with observations and in …
We present the target list of solar-type stars to be observed in short-cadence (2-min) for asteroseismology by the NASA Transiting Exoplanet Survey Satellite (TESS) during its 2-year nominal survey mission. The solar-like Asteroseismic Target List (ATL) is comprised of bright, cool main-sequence and subgiant stars and forms part of the larger target list of the TESS Asteroseismic Science Consortium (TASC). The ATL uses Gaia DR2 and the Extended Hipparcos Compilation (XHIP) to derive fundamental stellar properties, calculate detection probabilities and produce a rank-ordered target list. We pro…
Accurate line lists for three molecules, BeH, MgH and CaH, in their ground electronic states are presented. These line lists are suitable for temperatures relevant to exoplanetary atmospheres and cool stars (up to 2000K). A combination of empirical and \textit{ab initio} methods is used. The rovibrational energy levels of BeH, MgH and CaH are computed using the programs Level and DPotFit in conjunction with `spectroscopic' potential energy curves (PECs). The PEC of BeH is taken from the literature, while the PECs of CaH and MgH are generated by fitting to the experimental transition energy lev…
Stellar, substellar, and planetary atmosphere models are all highly sensitive to the input opacities. Generational differences between various state-of-the-art stellar/planetary models are primarily because of incomplete and outdated atomic/molecular line-lists. Here we present a database of pre-computed absorption cross-sections for all isotopologues of key atmospheric molecules relevant to late-type stellar, brown dwarf, and planetary atmospheres: MgH, AlH, CaH, TiH, CrH, FeH, SiO, TiO, VO, and H2O. The pressure and temperature ranges of the computed opacities are between 10$^{-6}$--3000~bar…
