J/A+A/582/A97 SSP in NIR. II. Synthesis models (Meneses-Goytia+, 2015)
Single stellar populations in the near-infrared. II. Synthesis models.
Meneses-Goytia S., Peletier R.F., Trager S.C., Vazdekis A.
<Astron. Astrophys. 582, A97 (2015)>
=2015A&A...582A..97M 2015A&A...582A..97M (SIMBAD/NED BibCode)
ADC_Keywords: Models, evolutionary ; Photometry, infrared
Keywords: stars: evolution - galaxies: stellar content - galaxies: evolution -
galaxies: formation - infrared: galaxies
Abstract:
We present unresolved single stellar population synthesis models in
the near-infrared (NIR) range. The extension to the NIR is important
for the study of early-type galaxies, since these galaxies are
predominantly old and therefore emit most of their light in this
wavelength range. The models are based on a library of empirical
stellar spectra, the NASA infrared telescope facility (IRTF) spectral
library. Integrating these spectra along theoretical isochrones, while
assuming an initial mass function (IMF), we have produced model
spectra of single age-metallicity stellar populations at a resolution
R∼2000. These models can be used to fit observed spectral of
globular clusters and galaxies, to derive their age distribution,
chemical abundances and IMF. The models have been tested by comparing
them to observed colours of elliptical galaxies and clusters in the
Magellanic Clouds. Predicted absorption line indices have been
compared to published indices of other elliptical galaxies. The
comparisons show that our models are well suited for studying stellar
populations in unresolved galaxies. They are particularly useful for
studying the old and intermediate-age stellar populations in galaxies,
relatively free from contamination of young stars and extinction by
dust. These models will be indispensable for the study of the upcoming
data from JWST and extremely large telescopes, such as the E-ELT.
Description:
The present Single Stellar Populations (SSP) models are derived from
my Ph.D.'s thesis and this paper.
The following nomenclature is used throughout the paper and the
website (http://smg.astro-research.net/ssp-models/the-models/) to
describe the models, e.g. MarS models use the M08 isochrones (Mar) and
the Salpeter (S) IMF.
General information about the models is given in table1.
For further information, please refer to the paper.
Each set of models and their corresponding predictions are available
in the website and VIZIER. The spectral energy distributions (SEDs)
can be downloaded in a zip-file from those pages in ascii format . The
spectral energy distributions (SEDs) can be downloaded in a zip-file
from t hose pages in ascii format . The nomenclature of each SED is as
follows: isochroneIMFsedXXXXHZX.XXXXXXXXXTgXX.XXXXXXXe+XX -
where XXXX tells whether those models contain C-stars or no (COMBO or
NOCS respectively) H is the spectral band in which normalization
occurred Z_X.XXXXXXXXX is the metallicity in terms of Z
Tg_XX.XXXXXXXe+XX is the age in years.
Each set of models contains
MarS - 96 SEDs
GirS - 96 SEDs
BaSS - 116 SEDs
We have also included in the websites the Integrated colours and
line-strength indices from all our models (MarS, GirS and BaSS).
The SEDs were convolved to a velocity dispersion of 350km/s before
calculating indices.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 67 96 Integrated colours and abundances for the MarS
models as a function of age and metallicity
tableb2.dat 67 96 Integrated colours and abundances for the GirS
models as a function of age and metallicity
tableb3.dat 67 116 Integrated colours and abundances for the BaSS
models as a function of age and metallicity
listsed.dat 93 308 List of SED
seds/* . 309 *Individual SED files
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Note on seds/*: The nomenclature of each SED is as follows:
isochroneIMFsedXXXXHZX.XXXXXXXXXTgXX.XXXXXXXe+XX.fits -
where XXXX tells whether those models contain C-stars or no
(COMBO or NOCS respectively), H is the spectral band in which normalization
occurred, Z_X.XXXXXXXXX is the metallicity in terms of Z and
Tg_XX.XXXXXXXe+XX is the age in years.
Each set of models contains
MarS - 96 SEDs
GirS - 96 SEDs
BaSS - 116 SEDs
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See also:
http://smg.astro-research.net/ssp-models/the-models : Models Home Page
Table1: Single Stellar Population model properties and parameter coverage
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Property Characteristics Notes
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Stellar library IRTF spectral library Stellar parameters
Wavelength range 0.93 - 2.41um J, H and K bands
Resolution 5.9Å at 1.22um See Paper I
Meneses-Goytia et al. 2015a
7.6Å at 1.62um
9.3Å at 2.02um
9.7Å at 2.27um
Wavelength frame vacuum
IMF Salpeter 1955 S
Stellar mass range 0.15 - 100.0 M☉
Metallicity range 0.70≤[Z/Zsun]≤0.20dex See Paper II for discussion
of the models at limits
Age range 1 - 14 Gyr
Isochrones Marigo et al. 2008A&A...482..883M 2008A&A...482..883M Mar
Girardi et al. 2000, Cat. J/A+AS/141/371 Gir
Pietrinferni et al. 2004ApJ...612..168P 2004ApJ...612..168P BaS
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Byte-by-byte Description of file (#): tableb1.dat tableb2.dat tableb3.dat
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Bytes Format Units Label Explanations
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1- 5 F5.2 Gyr Age Age
7- 11 F5.2 Sun [Z] Metallicity [Z/Zsun]
14- 18 F5.3 mag J-K J-K integrated colour
21- 25 F5.3 mag J-H J-H integrated colour
28- 32 F5.3 mag H-K H-K integrated colour
35- 39 F5.3 0.1nm NaI NaI abundance
42- 46 F5.3 0.1nm FeI FeI abundance
49- 53 F5.3 0.1nm CaI CaI abundance
55- 60 F6.3 0.1nm MgI MgI abundance
63- 67 F5.3 mag DCO DCO molecular index
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Byte-by-byte Description of file: listsed.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Iso [BAS GIR MAR] Isochrone (1)
5- 6 A2 --- IMF [SA] IMF, SA for Salpeter
8- 12 A5 --- Cstar Wether those models contain C-stars or no
(COMBO or NOCS respectively)
14- 25 F12.10 --- Z Metallicity Z
27- 39 E13.9 yr Age Age
42- 93 A52 --- FileName Name of the file with SED in subdirectory seds
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Note (1): Isochrones as follows:
BASv = Pietrinferni et al., 2004ApJ...612..168P 2004ApJ...612..168P
GIRv = Girardi et al., 2000, Cat. J/A+AS/141/371
MARv = Marigo et al., 2008A&A...482..883M 2008A&A...482..883M
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Byte-by-byte Description of file: seds/*
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Bytes Format Units Label Explanations
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7- 16 E10.8 um lambda Wavelength
20- 32 E13.8 Lsun/Msun/um Flux Flux
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Acknowledgements:
Sofia Meneses-Goytia, s.meneses-goytia(at)astro.rug.nl
(End) Patricia Vannier [CDS] 26-Aug-2015