- ID:
- ivo://CDS.VizieR/J/MNRAS/425/34
- Title:
- ExoMol line lists for BeH, MgH and CaH
- Short Name:
- J/MNRAS/425/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 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 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 levels. Both spin-rotation interactions (except for BeH, for which it is negligible) and non-adiabatic corrections are explicitly taken into account. Accurate line intensities are generated using newly computed ab initio dipole moment curves for each molecule using high levels of theory. Full line lists of rotation-vibration transitions for ^9^BeH, ^24^MgH, ^25^MgH, ^26^MgH and ^40CaH are made available in an electronic form as supplementary data to this article and at www.exomol.com .
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/1649
- Title:
- ExoMol line lists for CH4
- Short Name:
- J/MNRAS/440/1649
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 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 1500K. It covers the wavelengths longer than 1{mu}m and includes all transitions to upper states with energies below hc 18000cm^-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 SCHR equation for the rotation-vibration motion of nuclei employing program TROVE and a new 'spectroscopic' potential energy surface (PES) obtained by refining an ab initio PES (CCSD(T)-F12c/aug-cc-pVQZ) in a least-squares fitting to the experimentally derived energies with J=0, 1, 2, 3, 4 as extracted from the HITRAN database. The dipole transition probabilities are represented by the Einstein-A coefficients obtained using a previously reported ab initio dipole moment surface (CCSD(T)-F12c/aug-cc-pVTZ). Detailed comparisons with other available sources of methane transitions including HITRAN, experimental compilations and other theoretical line lists show that these sources lack transitions both higher temperatures and near infrared wavelengths. The 10to10 line list is suitable for modelling atmospheres of cool stars and exoplanets.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/1704
- Title:
- ExoMol line lists for formaldehyde H_2_CO
- Short Name:
- J/MNRAS/448/1704
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A computed line list for formaldehyde, H_2_^12^C^16^O, applicable to temperatures up to T=1500K is presented. An empirical potential energy and ab initio dipole moment surfaces are used as the input to nuclear motion program TROVE. The resulting line list, referred to as AYTY, contains 10.3 million rotational-vibrational states and around 10 billion transition frequencies. Each transition includes associated Einstein- A coefficients and absolute transition intensities, for wavenumbers below 10000cm^-1^ and rotational excitations up to J=70. Room-temperature spectra are compared with laboratory measurements and data currently available in the HITRAN database. These spectra show excellent agreement with experimental spectra and highlight the gaps and limitations of the HITRAN data. The full line list is available from the CDS database as well as at www.exomol.com.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/2337
- Title:
- ExoMol line lists for phosphine (PH_3_)
- Short Name:
- J/MNRAS/446/2337
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A comprehensive hot line list is calculated for ^31^PH_3_ in its ground electronic state. This line list, called SAlTY, contains almost 16.8 billion transitions between 7.5 million energy levels and it is suitable for simulating spectra up to temperatures of 1500K. It covers wavelengths longer than 1um and includes all transitions to upper states with energies below hc.18000cm^-1^ and rotational excitation up to J=46. The line list is computed by variational solution of the Schrodinger equation for the rotation-vibration motion employing the nuclear-motion program TROVE. A previously reported ab initio dipole moment surface is used as well as an updated 'spectroscopic' potential energy surface (PES), obtained by refining an existing ab initio surface through least-squares fitting to the experimentally derived energies. Detailed comparisons with other available sources of phosphine transitions confirms SAlTY's accuracy and illustrates the incompleteness of previous experimental and theoretical compilations for temperatures above 300K. Atmospheric models are expected to severely underestimate the abundance of phosphine in disequilibrium environments, and it is predicted that phosphine will be detectable in the upper troposphere of many substellar objects. This list is suitable for modelling atmospheres of many astrophysical environments, namely carbon stars, Y dwarfs, T dwarfs, hot Jupiters and solar system gas giant planets. It is available in full as supplementary data to the article and at www.exomol.com.
- ID:
- ivo://CDS.VizieR/J/MNRAS/434/1469
- Title:
- ExoMol line lists for SiO
- Short Name:
- J/MNRAS/434/1469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate rotation-vibration line lists are calculated for silicon monoxide. Line lists are presented for the main isotopologue, ^28^Si^16^O, and four monosubstituted isotopologues ^29^Si^16^O, ^30^Si^16^O, ^28^Si^17^O and ^28^Si^18^O, in their ground electronic states. These line lists are suitable for high temperatures (up to 9000K) including those relevant to exoplanetary atmospheres and cool stars. A combination of empirical and ab initio methods is used: the potential energy curves are determined to high accuracy by fitting to extensive data from analysis of both laboratory and sunspot spectra; a high quality ab initio dipole moment curve is calculated at the large basis set, multi-reference configuration interaction (MRCI) level. A partition function plus full line lists of rotation-vibration transitions are made available in an electronic form as supplementary data to this article and at www.exomol.com.
- ID:
- ivo://CDS.VizieR/J/ApJ/884/11
- Title:
- Exploring 6 AGN dusty torus models. II.
- Short Name:
- J/ApJ/884/11
- Date:
- 04 Dec 2021
- Publisher:
- CDS
- Description:
- This is the second in a series of papers devoted to exploring a set of six dusty models of active galactic nuclei (AGN) with available spectral energy distributions. These models are the smooth torus by Fritz+ (2006MNRAS.366..767F), the clumpy torus by Nenkova+ (2008ApJ...685..147N and 2008ApJ...685..160N), the clumpy torus by Honig & Kishimoto (2010A&A...523A..27H), the two-phase torus by Siebenmorgen+ (2015A&A...583A.120S), the two-phase torus by Stalevski+ (2012MNRAS.420.2756S and 2016MNRAS.458.2288S), and the wind model by Honig & Kishimoto (2017ApJ...838L..20H). The first paper explores discrimination among models and the parameter restriction using synthetic spectra. Here we perform spectral fitting of a sample of 110 AGN drawn from the Swift/BAT survey with Spitzer/IRS spectroscopic data. The aim is to explore which is the model that describes better the data and the resulting parameters. The clumpy wind-disk model by Honig & Kishimoto provides good fits for ~50% of the sample, and the clumpy torus model by Nenkova+ is good at describing ~30% of the objects. The wind-disk model by Honig & Kishimoto is better for reproducing the mid-infrared spectra of type 1 Seyferts (with 60% of the type 1 Seyferts well reproduced by this model compared to the 10% well represented by the clumpy torus model by Nenkova+), while type 2 Seyferts are equally fitted by both models (roughly 40% of the type 2 Seyferts). Large residuals are found irrespective of the model used, indicating that the AGN dust continuum emission is more complex than predicted by the models or that the parameter space is not well sampled. We found that all the resulting parameters for our AGN sample are roughly constrained to 10%-20% of the parameter space. Contrary to what is generally assumed, the derived outer radius of the torus is smaller (reaching up to a factor of ~5 smaller for 10pc tori) for the smooth torus by Fritz+ and the two-phase torus by Stalevski+ than the one derived from the clumpy torus by Nenkova+ Covering factors and line-of-sight viewing angles strongly depend on the model used. The total dust mass is the most robust derived quantity, giving equivalent results for four of these models.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/4364
- Title:
- Extended H2 emission from massive YSOs survey
- Short Name:
- J/MNRAS/450/4364
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a survey, designed to investigate the accretion process of massive young stellar objects (MYSOs) through near infrared narrow band imaging using the H_2_ {nu}=1-0 S(1) transition filter. A sample of 353 Massive Young Stellar Object (MYSO) candidates was selected from the Red MSX Source survey using photometric criteria at longer wavelengths (infrared and submillimeter) and chosen with positions throughout the Galactic Plane. Our survey was carried out at the SOAR Telescope in Chile and CFHT in Hawaii covering both hemispheres.
- ID:
- ivo://CDS.VizieR/J/A+A/515/A51
- Title:
- Extended red(dened) regions in 2MASS
- Short Name:
- J/A+A/515/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to identify extended red regions in the outer galactic plane based on reddening of stars in the near-infrared. We argue that these regions appear reddened mainly due to extinction caused by molecular clouds and young stellar objects. The work presented here is used as a basis for identifying star forming regions and in particular the very early stages. An accompanying paper describes the cross-identification of the identified regions with existing data, uncovering more on the nature of the reddening.
- ID:
- ivo://CDS.VizieR/J/ApJ/693/L81
- Title:
- Extinction in star-forming regions
- Short Name:
- J/ApJ/693/L81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Spitzer Infrared Spectrograph observations of G0-M4III stars behind dark clouds, I construct 5-20um empirical extinction curves for 0.3<=A_K_<7, which is equivalent to A_V_ between ~3 and 50. For A_K_<1, the curve appears similar to the Mathis diffuse interstellar medium extinction curve, but with a greater degree of extinction. For A_K_>1, the curve exhibits lower contrast between the silicate and absorption continuum, develops ice absorption, and lies closer to the Weingartner and Draine R_V_=5.5 Case B curve, a result which is consistent with that of Flaherty et al. (2007ApJ...663.1069F) and Chiar et al. (2007ApJ...666L..73C). Recently, work using Spitzer Infrared Array Camera data by Chapman et al. independently reaches a similar conclusion that the shape of the extinction curve changes as a function of increasing A_K_. By calculating the optical depths of the 9.7um silicate and 6.0, 6.8, and 15.2um ice features, I determine that a process involving ice is responsible for the changing shape of the extinction curve and speculate that this process is a coagulation of ice-mantled grains rather than ice-mantled grains alone.
- ID:
- ivo://CDS.VizieR/J/A+A/446/551
- Title:
- Extinctions at 7um & 15um from ISOGAL survey
- Short Name:
- J/A+A/446/551
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ISOGAL PSC data have been associated with near-infrared 2MASS sources, consisting a five-band photometric catalogue. In comparison with the ISOGAL-DENIS PSC catalogue, the number of fields in the ISOGAL-2MASS PSC is increased by 43 thanks to the 2MASS inclusion of the northern ISOGAL field. This point source catalogue contains all parameters of 7{mu}m or 15{mu}m from the ISOGAL PSC, together with the J H Ks bands data from the 2MASS All-Sky PSC (see the paper for a complete description). Based on the ISOGAL-2MASS PSC, the extinction laws at 7{mu}m and 15{mu}m are derived for more than 120 sightlines in the inner Galactic plane. The extinction values at 7{mu}m and 15{mu}m were in terms of the near-infrared extinction in the Ks band. The ratios that E(Ks-[7])/E(J-Ks) and E(Ks-[7])/E(Ks-[15]) are also displayed in the tables (see the paper for a complete description).
