J/ApJS/185/1 A catalog of star formation and metallicity (Tojeiro+, 2009)
A public catalog of stellar masses, star formation and metallicity histories,
and dust content from the Sloan Digital Sky Survey using VESPA.
Tojeiro R., Wilkins S., Heavens A.F., Panter B., Jimenez R.
<Astrophys. J. Suppl. Ser., 185, 1-19 (2009)>
=2009ApJS..185....1T 2009ApJS..185....1T (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Models
Keywords: catalogs - galaxies: evolution - galaxies: formation -
galaxies: stellar content - methods: data analysis - surveys
Abstract:
We applied the VESPA algorithm to the Sloan Digital Sky Survey (DR7)
of the Main Galaxies and Luminous Red Galaxies samples. The result is
a catalog of stellar masses, detailed star formation and metallicity
histories and dust content of nearly 800000 galaxies. We make the
catalog public via a T-SQL database. We present the results using a
range of stellar population and dust models, and will continue to
update the catalog as new and improved models are made public. We
also present a brief exploration of the catalog, and show that the
quantities derived are robust: luminous red galaxies can be described
by one to three populations, whereas a main galaxy sample galaxy needs
on average two to five; red galaxies are older and less dusty; the
dust values we recover are well correlated with measured Balmer
decrements and star formation rates are also in agreement with
previous measurements. We find that whereas some derived quantities
are robust to the choice of modelling, many are still not.
Description:
We use VESPA to analyze the SDSS-DR7 spectroscopic sample. The full
details of our method can be found in Tojeiro et al., 2007MNRAS.381.1252T 2007MNRAS.381.1252T.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
gal1.dat 121 683113 RunID1 results relative to the galaxy as a whole
gal2.dat 121 681311 RunID2 results relative to the galaxy as a whole
gal3.dat 121 687387 RunID3 results relative to the galaxy as a whole
gal4.dat 121 685586 RunID4 results relative to the galaxy as a whole
gal5.dat 121 89055 RunID5 results relative to the galaxy as a whole
gal6.dat 121 87207 RunID6 results relative to the galaxy as a whole
gal7.dat 121 89060 RunID7 results relative to the galaxy as a whole
gal8.dat 121 89061 RunID8 results relative to the galaxy as a whole
bin1.dat 88 5236152 RunID1 results relative to each age bin
bin2.dat 88 5140580 RunID2 results relative to each age bin
bin3.dat 88 5611841 RunID3 results relative to each age bin
bin4.dat 88 5535239 RunID4 results relative to each age bin
bin5.dat 88 390329 RunID5 results relative to each age bin
bin6.dat 88 388292 RunID6 results relative to each age bin
bin7.dat 88 633730 RunID7 results relative to each age bin
bin8.dat 88 632347 RunID8 results relative to each age bin
hrbin1.dat 74 10929808 RunID1 results relative to each bin into the
highest possible resolution (16 bins)
hrbin2.dat 74 10929808 RunID2 results relative to each bin into the
highest possible resolution (16 bins)
hrbin3.dat 74 10998208 RunID3 results relative to each bin into the
highest possible resolution (16 bins)
hrbin4.dat 74 10998208 RunID4 results relative to each bin into the
highest possible resolution (16 bins)
hrbin5.dat 74 1424880 RunID5 results relative to each bin into the
highest possible resolution (16 bins)
hrbin6.dat 74 1424128 RunID6 results relative to each bin into the
highest possible resolution (16 bins)
hrbin7.dat 74 1424976 RunID7 results relative to each bin into the
highest possible resolution (16 bins)
hrbin8.dat 74 1424976 RunID8 results relative to each bin into the
highest possible resolution (16 bins)
dust1.dat 27 1366226 RunID1 dust information
dust2.dat 27 1366226 RunID2 dust information
dust3.dat 27 1374776 RunID3 dust information
dust4.dat 27 1374776 RunID4 dust information
dust5.dat 27 178110 RunID5 dust information
dust6.dat 27 178016 RunID6 dust information
dust7.dat 27 178122 RunID7 dust information
dust8.dat 27 178122 RunID8 dust information
lookup.dat 46 781788 Links between VESPA's unique identifier with
SDSS's own identifiers
runprop.dat 20 8 Run-specific details (table7 of paper)
--------------------------------------------------------------------------------
See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
http://www-wfau.roe.ac.uk/vespa/ : VESPA home page
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: gal[1-8].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- index Unique identifier, constructed from SDSS's
plate, MJD and fiberID info (G1)
14 I1 --- runID [1,8] Gives detail of the run (G3)
16- 29 E14.8 Msun Mass Stellar mass (M*) (1)
31- 43 E13.11 Msun e_Mass Statistical error on Mass (σ(M*)) (2)
45- 57 E13.8 yr tlb Look-back time of galaxy, assuming a WMAP5
cosmology
59- 71 F13.8 --- chi2 χ2 of the unmasked regions used for
spectral fit
73- 84 F12.8 --- S/N Signal-to-noise ratio of the used (unmasked)
spectrum, at the models' resolution
86- 87 I2 --- Nb [0,16] Number of recovered bins in galaxy (G2)
88- 95 A8 --- --- [.0000 ]
97- 98 I2 --- Np [0,16] Number of recovered bins with
non-zero mass (G2)
99-106 A8 --- --- [.0000 ]
108-121 E14.11 --- z Redshift
--------------------------------------------------------------------------------
Note (1): We use the observed fiber and petrosian magnitudes in the z band to
scale up the stellar mass as:
M*=M*,fiber*100.4(zp-fzp_)^ - Equation (22)
where zp and fzp are the petrosian and fiber magnitudes in the z
band, respectively.
Note (2): We use the full covariance matrix to estimate the statistical
error on the total stellar mass, M*:
σ2(M*)=σ2(M*,fiber)γ2+
M2*,fiberσ2(γ) - Equation (26)
where γ is the conversion factor between fiber and galaxy mass
of Equation (22) (see note (1)), and σ(γ) is the error
associated with this factor, calculated using the errors in the
petrosian and fiber z-band magnitudes.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: bin[1-8].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- index Unique identifier, constructed from SDSS's
plate, MJD and fiberID info (G1)
14- 15 I2 --- binID [0,29] Bin identifier (α) as given in
Figure 1 (G2)
17 I1 --- runID [1,8] Gives detail of the run (G3)
19- 32 E14.10 Msun Mass ?=0 Mass formed in bin; corrected for fiber
aperture (1)
34- 46 E13.11 Msun e_Mass ?=0 Mass uncertainty (σu(α));
corrected for fiber aperture (2)
48- 60 E13.11 Msun/Gyr SFR ?=0 Star formation rate in the bin
62- 74 F13.11 --- Z ?=0 Metallicity in bin
76- 88 E13.11 --- e_Z ?=0 σZ(α) as derived from
Equation (24) (3)
--------------------------------------------------------------------------------
Note (1): For any given age bin α, the mass formed in each bin α
in units of solar masses is given by the equation (17):
uα=xα4πDL2(1+z).
Note (2): For convenience, we also define a covariance matrix of the
unrecycled mass per bin as (using Equation (17)):
Cαβ(u)=Cαβ(x)[4πDL2(1+z)]2
- Equation (25) - from which we can estimate the error in the unscaled
mass formed in bin α as
σu(α)=Cαα(u)0.5.
Note (3): To estimate how much noise affects our recovered solutions we take
a rather empirical approach. For each recovered solution we create
nerror random noisy realizations and we apply VESPA to each of these
spectra. In the current runs we have used nerror=20. We re-bin each
recovered solution in the parametrization of the solution we want to
analyze and estimate the covariance matrices:
C(Z)αβ=<(Zα-Z{bar}α)(Zβ-Z{bar}β_)>
- equation (24).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: hrbin[1-8].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- index Unique identifier, constructed from SDSS's
plate, MJD and fiberID info (G1)
14- 15 I2 --- binID [0,15] Bin identifier (α) as given in
Figure 1 (G2)
17 I1 --- runID [1,8] Gives detail of the run (G3)
19- 32 E14.10 Msun Mass ?=0 Mass formed in bin; with weights from
Equation (7) and corrected for fiber aperture (1)
34- 46 E13.11 Msun e_Mass ?=0 Mass uncertainty (σu(α)); with
weights from Equation (7) and corrected for
fiber aperture (2)
48- 60 F13.11 --- Z ?=0 Metallicity in bin
62- 74 E13.11 --- e_Z ?=0 σZ(α) as derived from
Equation (24) (3)
--------------------------------------------------------------------------------
Note (1): For any given age bin α, the mass formed in each bin α
in units of solar masses is given by the equation (17):
uα=xα4πDL2(1+z).
See section 2.1.2 for high-resolution bins explanations.
Note (2): For convenience, we also define a covariance matrix of the
unrecycled mass per bin as (using Equation (17)):
Cαβ(u)=Cαβ(x)[4πDL2(1+z)]2
- Equation (25) - from which we can estimate the error in the unscaled
mass formed in bin α as
σu(α)=Cαα(u)0.5.
See section 2.1.2 for high-resolution bins explanations.
Note (3): To estimate how much noise affects our recovered solutions we take
a rather empirical approach. For each recovered solution we create
nerror random noisy realizations and we apply VESPA to each of these
spectra. In the current runs we have used nerror=20. We re-bin each
recovered solution in the parametrization of the solution we want to
analyze and estimate the covariance matrices:
C(Z)αβ=<(Zα-Z{bar}α)(Zβ-Z{bar}β_)>
- equation (24).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: dust[1-8].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- index Unique identifier, constructed from SDSS's
plate, MJD and fiberID info (G1)
14 I1 --- runID [1,8] Gives detail of the run (G3)
16 I1 --- dustID [1/2] Dust identifier: 1 for τBCV and
2 for τISMV
18- 22 F5.3 --- dustVal [0,4] Value of dust extinction; either
τBCV or τISMV, according to
dustID
23- 27 A5 --- --- [000 ]
--------------------------------------------------------------------------------
Byte-by-byte Description of file: lookup.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- index Unique identifier, constructed from SDSS's
plate, MJD and fiberID info (G1)
14- 18 I5 --- MJD SDSS-DR7 MJD (=bytes 1-5)
20- 23 I4 --- Plate SDSS-DR7 Plate (=bytes 6-9)
25- 27 I3 --- Fiber SDSS-DR7 Fiber (=bytes 10-12)
29- 46 A18 --- SpecObj SDSS-DR7 specObjID
(=plate*248 + MJD*232 + fiber*222)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: runprop.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 I1 --- runID [1,8] Unique run ID (G3)
3- 6 A4 --- SSP Single stellar population (SSP) model used:
BC03 (Bruzual & Charlot 2003MNRAS.344.1000B 2003MNRAS.344.1000B) or
M05 (Maraston, 2005MNRAS.362..799M 2005MNRAS.362..799M)
8- 10 F3.1 --- V1.0 [1.0] VESPA code version
12 I1 --- dustID [1/2] Dust model used (1 for τBCV and
2 for τISMV)
14- 16 A3 --- SDSS [DR7] SDSS's data release
18- 20 A3 --- Sample [MGS/LRG] MGS for Main Galaxies Sample or
LRG for Luminous Red Galaxies Sample (LRGS)
--------------------------------------------------------------------------------
Global Notes:
Note (G1): index constructed as
MJD*107 + plate*103 + fiberID
Note (G2): Grid of bins used by VESPA (figure 1) as follows:
---------------------------------------------------------
binID (HR) Age (Gyr) binID Age (Gyr)
---------------------------------------------------------
0 0.00-0.02 16 0.00-0.03
1 0.02-0.03 17 0.03-0.07
2 0.03-0.05 18 0.07-0.18
3 0.05-0.07 19 0.18-0.42
4 0.07-0.11 20 0.42-1.00
5 0.11-0.18 21 1.00-2.40
6 0.18-0.27 22 2.40-5.50
7 0.27-0.42 23 5.50-14.0
8 0.42-0.66
9 0.66-1.00 24 0.00-0.07
10 1.00-1.60 25 0.07-0.42
11 1.60-2.40 26 0.42-2.40
12 2.40-3.80 27 2.40-14.0
13 3.80-5.50
14 5.50-9.00 28 0.00-0.42
15 9.00-14.0 29 0.42-14.0
---------------------------------------------------------
Note (G3): Explanations given in "runprop.dat" (table7 of paper),
with parameters:
* Population models are BC03 (Bruzual & Charlot 2003MNRAS.344.1000B 2003MNRAS.344.1000B)
or M05 (Maraston 2005MNRAS.362..799M 2005MNRAS.362..799M)
* dust models are ISM (interstellar extinction), or BC (birth
cloud additional extinction)
* sample is MGS (Main Galaxies Sample) or LRG (Luminous Red Galaxies)
1 = pop=BC03 dust=BC MGS
2 = pop=BC03 dust=ISM MGS
3 = pop=M05 dust=BC MGS
4 = pop=M05 dust=ISM MGS
5 = pop=BC03 dust=BC LRG
6 = pop=BC03 dust=ISM LRG
7 = pop=M05 dust=BC LRG
8 = pop=M05 dust=ISM LRG
--------------------------------------------------------------------------------
History:
Copied at http://www-wfau.roe.ac.uk/vespa/download/; v13-May-2010 and
28-Mar-2011 for runID5.
(End) Emmanuelle Perret [CDS] 14-Mar-2011