J/ApJ/676/286 Spectral templates for galaxies from 0.2 to 10um (Assef+, 2008)
Low-resolution spectral templates for galaxies from 0.2 to 10 µm.
Assef R.J., Kochanek C.S., Brodwin M., Brown M.J.I., Caldwell N.,
Cool R.J., Eisenhardt P., Eisenstein D., Gonzalez A.H., Jannuzi B.T.,
Jones C., McKenzie E., Murray S.S., Stern D.
<Astrophys. J., 676, 286-303 (2008)>
=2008ApJ...676..286A 2008ApJ...676..286A
ADC_Keywords: Models ; Spectroscopy ; Magnitudes, absolute
Keywords: galaxies: distances and redshifts -
galaxies: luminosity function, mass function - galaxies: photometry
Abstract:
We built an optimal basis of low-resolution templates for galaxies
over the wavelength range from 0.2 to 10um using a variant of the
algorithm presented by Budavari and coworkers. We derived them using
11 bands of photometry from the NDWFS, FLAMEX, zBootes, and IRAC
Shallow surveys for 16033 galaxies in the NDWFS Bootes field with
spectroscopic redshifts measured by the AGN and Galaxy Evolution
Survey. We also developed algorithms to accurately determine
photometric redshifts, K-corrections, and bolometric luminosities
using these templates. Our photometric redshifts have an accuracy of
sigmaz/(1+z)=0.04 when clipped to the best 95%. We used these
templates to study the spectral type distribution in the field and to
estimate luminosity functions of galaxies as a function of redshift
and spectral type. In particular, we note that the 5-8um color
distribution of galaxies is bimodal, much like the optical g-r colors.
Description:
The NOAO Deep Wide-Field Survey is a deep optical and near-infrared
imaging survey that covers two 9.3deg2 fields, the Bootes and Cetus
fields. Both fields were imaged in BW (3500-4750Å, peak at
∼4000Å), R , and I passbands to depths (5σ, 2" diameter
aperture) of approximately 26.5, 26, and 25.5 AB magnitude. Both NDWFS
fields have been completely imaged in the K and Ks bands to a
limiting AB magnitude of 21.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 158 453 Three template model absolute magnitudes
table2.dat 158 604 Four template model absolute magnitudes
table3.dat 41 160 Three component spectral templates
table4.dat 52 160 Four component spectral templates
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Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 5 F5.3 --- z Redshift
7 I1 --- t [1/4] Template number: 1=E, 2=Sbc, 3=Im,
4=E+A (post-starburst galaxy)
9- 15 F7.3 mag BWMAG Absolute BW band magnitude (2)
17- 23 F7.3 mag BMAG Absolute B band magnitude (2)
25- 31 F7.3 mag VMAG Absolute V band magnitude (2)
33- 39 F7.3 mag RMAG Absolute R band magnitude (2)
41- 47 F7.3 mag IMAG Absolute I band magnitude (2)
49- 55 F7.3 mag uMAG Absolute SDSS u' band AB magnitude (2)
57- 63 F7.3 mag gMAG Absolute SDSS g' band AB magnitude (2)
65- 71 F7.3 mag rMAG Absolute SDSS r' band AB magnitude (2)
73- 79 F7.3 mag iMAG Absolute SDSS i' band AB magnitude (2)
81- 87 F7.3 mag zMAG Absolute SDSS z' band AB magnitude (2)
89- 95 F7.3 mag JMAG Absolute 2MASS J band magnitude (2)
97-103 F7.3 mag HMAG Absolute 2MASS H band magnitude (2)
105-111 F7.3 mag KSMAG Absolute 2MASS KS band magnitude (2)
113-119 F7.3 mag KMAG Absolute K band magnitude (2)
121-127 F7.3 mag 3.6MAG Absolute Spitzer/IRAC 3.6 micron band magnitude (2)
129-135 F7.3 mag 4.5MAG Absolute Spitzer/IRAC 4.5 micron band magnitude (2)
137-143 F7.3 mag 5.8MAG Absolute Spitzer/IRAC 5.8 micron band magnitude (2)
145-151 F7.3 mag 8.0MAG Absolute Spitzer/IRAC 8.0 micron band magnitude (2)
153-158 F6.3 mag DM ? Distance Modulus
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Note (2): The absolute magnitude we present here corresponds to the
canonical definition of the absolute magnitude (as in, for example,
eq. 26 of Hogg 1999, 9905116) plus the K correction term.
This allows the calculation of photometric redshifts and K corrections
from the table. To determine photometric redshifts, colors should be
calculated and matched to the data by varying the ak coefficients
(see Section 3.1) and the redshift. For a galaxy at redshift z with
template coefficients ak, the model magnitude in band b is given by
Mb(z)=-2.5log[sumk(ak 10-0.4Mb,k_(z)^)]. Apparent magnitudes
can be determined by adding the distance modulus to the absolute ones.
To determine K corrections for a galaxy at redshift z, coefficients
ak should also be determined to match the observed colors as above.
With the same coefficients, redshift z and redshift zero model
absolute magnitudes can be determined, and the difference between them
will correspond to the desired K correction.
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Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
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1- 8 F8.6 um lambda Wavelength
10- 19 E10.4 mW/m2/Hz E Best fit Elliptical template Fnu (1)
21- 30 E10.4 mW/m2/Hz Sbc Best fit Sbc Spiral Sbc template Fnu (1)
32- 41 E10.4 mW/m2/Hz Im Best fit Irregular Im template Fnu (1)
43- 52 E10.4 mW/m2/Hz E+A ? Best fit E+A template Fnu (table4 only )(1)
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Note (1): In units of erg/s/cm2/Hz (=mW/m2/Hz=1023Jy). Templates
are normalized to be at a distance of 10pc and to have an integrated
luminosity between the wavelength boundaries of 1010L☉.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 30-Jul-2010