- ID:
- ivo://CDS.VizieR/J/ApJ/808/21
- Title:
- Methyl acetate (CH_3_COOCH_3_) rotational transitions
- Short Name:
- J/ApJ/808/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Methyl acetate (CH_3_COOCH_3_) has been recently observed by the IRAM 30m radio telescope in Orion, though the presence of its deuterated isotopomers is yet to be confirmed. We therefore study the properties of various forms of methyl acetate, namely, CH_3_COOCH_3_, CH_2_DCOOCH_3_, and CH_3_COOCH_2_D. Our simulation reveals that these species could be produced efficiently in both gas and ice phases. Production of methyl acetate could follow radical-radical reaction between acetyl (CH_3_CO) and methoxy (CH_3_O) radicals. To predict abundances of CH_3_COOCH_3_ along with its two singly deuterated isotopomers and its two isomers (ethyl formate and hydroxyacetone), we prepare a gas-grain chemical network to study the chemical evolution of these molecules. Since gas-phase rate coefficients for methyl acetate and its related species are unknown, either we consider similar rate coefficients for similar types of reactions (by following existing databases) or we carry out quantum chemical calculations to estimate the unknown rate coefficients. For the surface reactions, we use adsorption energies of reactants from some earlier studies. Moreover, we perform quantum chemical calculations to obtain spectral properties of methyl acetate in infrared and sub-millimeter regions. We prepare two catalog files for the rotational transitions of CH_2_DCOOCH_3_ and CH_3_COOCH_2_D in JPL format, which could be useful for their detection in regions of interstellar media where CH_3_COOCH_3_ has already been observed.
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- ID:
- ivo://CDS.VizieR/J/ApJS/156/69
- Title:
- MGGPOD Monte Carlo suite
- Short Name:
- J/ApJS/156/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Intense and complex instrumental backgrounds, against which the much smaller signals from celestial sources have to be discerned, are a notorious problem for low- and intermediate-energy {gamma}-ray astronomy (~50keV-10MeV). Therefore, a detailed qualitative and quantitative understanding of instrumental line and continuum backgrounds is crucial for most stages of {gamma}-ray astronomy missions, ranging from the design and development of new instrumentation through performance prediction to data reduction. We have developed MGGPOD, a user-friendly suite of Monte Carlo codes built around the widely used GEANT (ver. 3.21) package, to simulate ab initio the physical processes relevant for the production of instrumental backgrounds. These include the build-up and delayed decay of radioactive isotopes as well as the prompt de-excitation of excited nuclei, both of which give rise to a plethora of instrumental {gamma}-ray background lines in addition to continuum backgrounds. The MGGPOD package and documentation are publicly available online (http://sigma-2.cesr.fr/spi/MGGPOD/). We demonstrate the capabilities of the MGGPOD suite by modeling high-resolution {gamma}-ray spectra recorded by the Transient Gamma-Ray Spectrometer (TGRS) on board Wind during 1995. The TGRS is a Ge spectrometer operating in the 40keV-8MeV range. Because of its fine energy resolution, these spectra reveal the complex instrumental background in formidable detail, particularly the many prompt and delayed {gamma}-ray lines. We evaluate the successes and failures of the MGGPOD package in reproducing TGRS data and provide identifications for the numerous instrumental lines.
- ID:
- ivo://CDS.VizieR/J/A+AS/105/311
- Title:
- M giants spectra and photometry
- Short Name:
- J/A+AS/105/311
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From a sample of 97 very bright M-giant stars in the Solar neighbourhood, high-quality `intrinsic' spectra in the spectral range [380-900]nm for all M-spectral subclasses of the Case and MK classification systems are obtained. The results are fitted to photospheric synthetic spectra in the range [99-12500]nm in order to infer the corresponding continua. The synthetic spectra are also compared to the intrinsic spectra. The effective temperatures are derived and mathematical spectral classification criteria are found. The (UB)j(VRI)c(JHKLM)eso photometric data of the sample are also given.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A63
- Title:
- MHD shock code mhd_vode
- Short Name:
- J/A+A/578/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The planar MHD shock code_mhd vode has been developed in order to simulate both "continuous" (C) type shock waves and "jump" (J) type shock waves in the interstellar medium. The physical and chemical state of the gas in steady-state may also be computed and used as input to a shock wave model. The code is written principally in FORTRAN 90, although some routines remain in FORTRAN 77. The documented program and its input data are described and provided as supplementary material, and the results of exemplary test runs are presented. Our intention is to enable the interested user to run the code for any sensible parameter set and to comprehend the results. With applications to molecular outflow sources in mind, we have computed, and are making available as supplementary material, integrated atomic and molecular line intensities for grids of C- and J-type models; these computations are summarized in the Appendices.
- ID:
- ivo://CDS.VizieR/J/MNRAS/404/1639
- Title:
- MILES base models & new line index system
- Short Name:
- J/MNRAS/404/1639
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present synthetic spectral energy distributions (SEDs) for single-age, single-metallicity stellar populations (SSPs) covering the full optical spectral range at moderately high resolution [full width at half-maximum (FWHM)=2.3{AA}]. These SEDs constitute our base models, as they combine scaled-solar isochrones with an empirical stellar spectral library [Medium resolution INT Library of Empirical Spectra (MILES)], which follows the chemical evolution pattern of the solar neighbourhood. The models rely as much as possible on empirical ingredients, not just on the stellar spectra, but also on extensive photometric libraries, which are used to determine the transformations from the theoretical parameters of the isochrones to observational quantities. The unprecedented stellar parameter coverage of the MILES stellar library allowed us to safely extend our optical SSP SED predictions from intermediate- to very-old-age regimes and the metallicity coverage of the SSPs from super-solar to [M/H]=-2.3. SSPs with such low metallicities are particularly useful for globular cluster studies. We have computed SSP SEDs for a suite of initial mass function shapes and slopes. We provide a quantitative analysis of the dependence of the synthesized SSP SEDs on the (in)complete coverage of the stellar parameter space in the input library that not only shows that our models are of higher quality than those of other works, but also in which range of SSP parameters our models are reliable.
- ID:
- ivo://CDS.VizieR/J/MNRAS/371/703
- Title:
- MILES library of empirical spectra
- Short Name:
- J/MNRAS/371/703
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new stellar library developed for stellar population synthesis modelling is presented. The library consists of 985 stars spanning a large range in atmospheric parameters. The spectra were obtained at the 2.5-m Isaac Newton Telescope and cover the range 3525-7500{AA} at 2.3{AA} (full width at half-maximum) spectral resolution. The spectral resolution, spectral-type coverage, flux-calibration accuracy and number of stars represent a substantial improvement over previous libraries used in population-synthesis models.
- ID:
- ivo://CDS.VizieR/J/ApJ/885/87
- Title:
- Milky Way mass model and rotation curve
- Short Name:
- J/ApJ/885/87
- Date:
- 15 Mar 2022 08:00:47
- Publisher:
- CDS
- Description:
- We discuss a model for the Milky Way obtained by fitting the observed terminal velocities with the radial acceleration relation. The resulting stellar surface density profile departs from a smooth exponential disk, having bumps and wiggles that correspond to massive spiral arms. These features are used to estimate the term for the logarithmic density gradient in the Jeans equation, which turn out to have exactly the right location and amplitude to reconcile the apparent discrepancy between the stellar rotation curve and that of the interstellar gas. This model also predicts a gradually declining rotation curve outside the solar circle with slope -1.7km/s/kpc, as subsequently observed.
- ID:
- ivo://CDS.VizieR/J/A+A/317/761
- Title:
- Miras temperatures, distances & magnitudes
- Short Name:
- J/A+A/317/761
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Effective temperatures are determined for a sample of 165 oxygen-rich Miras using indices related to molecular band strength of titanium oxide and vanadium oxide. Using a theoretical evolutionary track on AGB, absolute bolometric magnitudes are computed. Apparent bolometric magnitudes are determined from narrow-band photometry observations. They are used to calibrate distances.
- ID:
- ivo://CDS.VizieR/J/ApJ/858/28
- Title:
- Mixing-length parameter for a sample of KIC stars
- Short Name:
- J/ApJ/858/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar models typically use the mixing-length approximation as a way to implement convection in a simplified manner. While conventionally the value of the mixing-length parameter, {alpha}, used is the solar-calibrated value, many studies have shown that other values of {alpha} are needed to properly model stars. This uncertainty in the value of the mixing-length parameter is a major source of error in stellar models and isochrones. Using asteroseismic data, we determine the value of the mixing-length parameter required to properly model a set of about 450 stars ranging in logg, Teff, and [Fe/H]. The relationship between the value of {alpha} required and the properties of the star is then investigated. For Eddington atmosphere, non-diffusion models, we find that the value of {alpha} can be approximated by a linear model, in the form of {alpha}/{alpha}_{sun}_=5.426-0.101, log(g)-1.071, log(Teff)+0.437([Fe/H]). This process is repeated using a variety of model physics, as well as compared with previous studies and results from 3D convective simulations.
- ID:
- ivo://CDS.VizieR/J/A+A/504/359
- Title:
- Mock spectro-photometric catalog of galaxies
- Short Name:
- J/A+A/504/359
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Future dark energy space missions such as JDEM and EUCLID are being designed to survey the galaxy population to trace the geometry of the universe and the growth of structure, which both depend on the cosmological model. To reach the goal of high precision cosmology they need to evaluate the capabilities of different instrument designs based on realistic mock catalog. The aim of this paper is to construct realistic and flexible mock catalogs based on our knowledge of galaxy population from current deep surveys. We explore two categories of mock catalog : (i) based on luminosity functions fit of observations (GOODS, UDF, COSMOS, VVDS) using the Le Phare software (ii) based on the observed COSMOS galaxy distribution which benefits from all the properties of the data-rich COSMOS survey. For these two catalogs, we have produced simulated number counts in several bands, color diagrams and redshift distribution for validation against real observational data. We also derive some basic requirements to help designing future Dark Energy mission in terms of number of galaxies available for the weak-lensing analysis as a function of the PSF size and depth of the survey. We also compute the spectroscopic success rate for future spectroscopic redshift surveys (i) aiming at measuring BAO in the case of the wide field spectroscopic redshift survey, and (ii) for the photometric redshift calibration survey which is required to achieve weak lensing tomography with great accuracy. They will be publicly accessible at http://lamwws.oamp.fr/cosmowiki/RealisticSpectroPhotCat, or by request to the first author of this paper.
