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J/AJ/121/2895 HDF-N Caltech faint galaxy redshift survey. XIII. (Cohen 2001)
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Caltech Faint Galaxy Redshift Survey.
XIII. Spectral energy distributions for galaxies in the region of the
Hubble Deep Field North.
Cohen J.G.
<Astron. J. 121, 2895 (2001)>
=2001AJ....121.2895C
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ADC_Keywords: Galaxy catalogs ; Energy distributions ; Redshifts
Keywords: cosmology: observations - galaxies: fundamental parameters -
galaxies: luminosity function, mass function - surveys
Abstract:
We introduce a new empirical function for modeling the spectral energy
distributions (SEDs) of galaxies. We apply it to a sample of 590
galaxies in the region of the Hubble Deep Field (HDF) with z<1.5
using multicolor photometry with wide wavelength coverage combined
with spectroscopic redshifts from our 93% complete R-selected redshift
survey there.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 542 SED Parameters for Objects in the Region of the HDF
table6a.dat 45 53 Additional redshifts for galaxies in the HDF-N
table6b.dat 50 5 Additional redshifts for galaxies in the flanking
fields of the HDF-N
table7a.dat 64 47 SED parameters for additional galaxies in the
flanking fields of the HDF-N
table7b.dat 64 2 SED parameters for additional galaxies in the HDF-N
table8.dat 40 3 Corrections to redshifts for galaxies in the HDF-N
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See also:
J/ApJS/127/1 : UGRK Photometry in the Hubble Deep field region (Hogg+, 2000)
J/ApJ/538/29 : HDF-N Caltech Faint Galaxy Redshift Survey. X. (Cohen+, 2000)
Byte-by-byte Description of file: table1.dat table7a.dat table7b.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right Ascension (J2000) (1)
4- 5 I2 min RAm Right Ascension (J2000)
7- 11 F5.2 s RAs Right Ascension (J2000)
13 A1 --- DE- Sign of the Declination (J2000)
14- 15 I2 deg DEd Declination (J2000)
17- 18 I2 arcmin DEm Declination (J2000)
20- 23 F4.1 arcsec DEs Declination (J2000)
25- 29 F5.2 [W] logLB Log of the B band luminosity (2)
31- 34 F4.2 --- UV2p Rest frame UV power law index of the 2p SED
model (3)
36- 40 F5.2 --- IR2p Rest frame power law index in the region
redward of 4000{AA} of the 2p SED model (3)
42- 46 F5.2 --- UVsBB Rest frame UV index of the "stretched black
body" (sBB) SED model (3)
48- 52 F5.2 [W] logLblue Log of the blue {lambda}_m_ side luminosity
of the sBB SED model (3)
54- 58 I5 --- Temp Planck function temperature in the sBB SED
model (3)
60- 64 F5.2 [W] logLred Log of the red {lambda}_m_ side luminosity
of the sBB SED model (3)
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Note (1): Objects are identified as [C2001b] JHHMMSS.ss+DDMMSS.s in Simbad
Note (2): M_B_ = -21.0 (rest frame) is equivalent to logLB = 36.9.
Note (3): Models:
We initially adopted the same form for SEDs as Cohen et al.
(1999ApJ...512...30C), namely, we assume that the emitted luminosity
per unit frequency in the rest frame over the wavelength regime
0.2-1.6{mu} can be represented by a power law whose index may change
at 4000{AA}. Thus L_{nu}_, with units of watts per hertz, is assumed
to be ~{nu}^-{alpha}^, with an index in the region redward of 4000{AA}
(in the rest frame), denoted by {alpha}_IR_, and an index in the
rest-frame UV of {alpha}_UV_. Three parameters are required to
characterize each SED. We refer to this as the 2p SED model.
To avoid the difficulties of the 2p SED model described above, we have
developed a new model for galaxy SEDs. One natural way to introduce
the desired curvature in the optical and near-IR spectra region is to
replace the power law with a blackbody function. However, the peak of
the Planck function itself is too narrow to give a good fit to actual
galaxy SEDs, as one might expect for a composite stellar population
containing stars with a range of effective temperatures. The
empirically determined function we adopt as our SED model, which
provides a simple but versatile parameterization of galaxy SEDs with
parameters that are physically motivated, has a mathematical form that
we denote as a "stretched blackbody" (henceforth sBB). We apply the
sBB function to fit the optical/near-IR, while we retain a power-law
fit to the UV.
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Byte-by-byte Description of file: table6a.dat table6b.dat table8.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right Ascension (J2000)
4- 5 I2 min RAm Right Ascension (J2000)
7- 11 F5.2 s RAs Right Ascension (J2000)
13 A1 --- DE- Sign of the Declination (J2000)
14- 15 I2 deg DEd Declination (J2000)
17- 18 I2 arcmin DEm Declination (J2000)
20- 23 F4.1 arcsec DEs Declination (J2000)
25- 29 F5.2 mag Rmag R magnitude
31- 35 F5.3 --- z Redshift (1)
37- 38 I2 --- q_z Quality (2)
40- 41 A2 --- Sp [AEIM ] Spectral type (3)
43- 52 A10 --- r_z Source of redshift (4)
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Note (1): adopted redshift in table8
Note (2): Quality class:
1: Multiple features, sigma(z)<=0.002/feature
2: Multiple features, sigma(z)<=0.004/feature
3: Multiple features, faint, id uncertain,
sigma(z) small 75% of time, and wildly off 25% of time
4: One emission line only, solid, assume 3727{AA}
5: One emission line only, reality uncertain, assume 3727{AA}
6: Multiple features, at least one broad emission line
7: Only one broad emission line, assumed to be 2800{AA}
8: Single break, assumed to be 4000{AA} break
9: Single strong absorption feature, assumed to be 2800{AA}
because of shape of continuum
0: No redshift
11: Not specified in the text (only 3 objects)
Note (3): Spectral type:
A: No emission lines, only absorption features (corresponds to E)
E: Dominated by emission lines, 3727, 5007 (corresponds to Sc)
I: Intermediate (corresponds to Sa)
M: TiO bands (M dwarfs); CaH bands (M subdwarfs)
Note (4): Source of redshift:
AS: From Adelberger & Steidel, 2000ApJ...544..218A
Cal: This work
St0: Not specified
Daw: From Dawson et al., 2001AJ....122..598D
Stern: Published in Stern & Spinrad, 1999PASP..111.1475S
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History:
From electronic version of the journal
References:
Cohen et al., Paper VII 1999ApJS..120..171C
Cohen et al., Paper VIII 1999ApJ...512...30C
Hogg et al., Paper IX 2000ApJS..127....1H, Cat. <J/ApJS/127/1>
Cohen et al., Paper X 2000ApJ...538...29C, Cat. <J/ApJ/538/29>
Carlberg et al., Paper XI 2000ApJ...532L...1C
Hogg et al., Paper XII 2000ApJ...545...32H
Cohen, Paper XIII 2001AJ....121.2895C, Cat. <J/AJ/121/2895>
van den Bergh et al., Paper XIV 2000AJ....120.2190V
van den Bergh et al., Paper XV 2001AJ....122..611V
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(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 11-Sep-2001