Data model: portsmouth_stellarmass

General description: This file contains the plate merged output of the Portsmouth Spectro-Photometric Stellar Mass computation of the BOSS galaxy product, according to the algorithm documentation.

Configurations:

The Portsmouth Stellar Mass Computation is calculated for two templates based on Maraston et al. (2005) and Maraston et al. (2009) models, each for two Initial Mass Functions. No reddening is used for the best-fitting.

(configname)	SP Model	IMF
passive_krou	Passive	Kroupa
passive_salp	Passive	Salpeter
starforming_krou	Star Forming	Kroupa
starforming_salp	Star Forming	Salpeter

Passive SP Model:

The passive model is the best-fit LRG model of Maraston et al. (2009), which is composed of:

97% by mass of a solar metallicity simple stellar population (SSP) plus 3% by mass of a metal-poor SSP, both coeval
The minimum age is set to be 3 Gyr.

Star Forming SP Model:

As in Maraston et al. (2006), a best-fit template is simultaneously selected from 1 of 4 metallicities, with Z='0.004', '0.01', '0.02', or '0.04' [where Z_sun=0.02], and 1 of the following stellar formation histories (SFH):

exponentially declining SFH (τ-models) for values of τ=0.1, 0.3 or 1 Gyr
truncated SFH: meaning constant star formation up to time τ=0.1, 0.3 and 1 Gyr and no star formation afterward
constant SFH

Naming convention: portsmouth_stellarmass_(configname)-RUN2D.fits

Approximate size: 100 Mbytes.

File type: FITS

Read by products: galaxy/portsmouth_stellarmass

Written by products: galaxy/portsmouth_stellarmass

File Contents:

HDU 0: NULL - Empty
HDU 1: fields - Binary FITS Table, Object Spectro-Photometric Stellar Masses

FITS Header Keywords (HDU 1):

AUTHOR: File Authors
VERSIDL: Version of IDL
VERSUTIL: Version of idlutils
VERS2D: Version of idlspec2d for 2D reduction
VERS1D: Version of idlspec2d for 1D reduction
VERSGAL: Version of GALAXY product
MODEL: Starforming or Passive
IMF: IMF applied to the stellar population model

HDU 1 Binary FITS Table fields:

PLATE (LONG): Plate number
MJD (LONG): Modified Julian date of observation
FIBERID (LONG): Fiber ID (1 to 1000)
RA (DOUBLE): Object RA (Plug_RA drilled fiber position) [J2000 degrees]
Dec (DOUBLE): Object Dec (Plug_Dec drilled fiber position) [J2000 degrees]
z (FLOAT): Redshift (best pipeline galaxy z_noqso with zwarning_noqso=0)
z_err (FLOAT): Redshift error (z_err_noqso) based upon fit to chi² minimum
znum (INT): the znum-th best-fit corresponding to z_noqso (optional input to readspec)
MagScaled (FLOAT[5]): MagScaled[ugriz] = modelmag[ugriz] + cmodelmag[i]-modelmag[i] - extinction[ugriz] (see PhotoObj for definitions).
MagScaled_err (FLOAT[5]): MagScaled_err[ugriz] = MagScaled[ugriz] * modelmagerr[ugriz]/modelmag[ugriz] (see PhotoObj for definitions).
LogMass (FLOAT): Best-fit stellar mass of galaxy [in log M_sun]
MinLogMass (FLOAT): Minimum stellar mass (lower 68% confidence level of logmass) [in log M_sun]
MaxLogMass (FLOAT): Maximum stellar mass (upper 68% confidence level of logmass) [in log M_sun]
MedianPDF (FLOAT): Median value of the logmass PDF [in log M_sun]
PDF16 (FLOAT): Value of PDF at which 16% of the logmass probability is accumulated [in log M_sun]
PDF84 (FLOAT): Value of PDF at which 84% of the logmass probability is accumulated [in log M_sun]
PeakPDF (FLOAT): Peak value of logmass PDF [in log M_sun]
LogMass_noMassLoss (FLOAT): Best-fit stellar mass of galaxy without mass loss [in log M_sun]
MinLogMass_noMassLoss (FLOAT): Minimum stellar mass (lower 68% confidence level of logmass) without mass loss [in log M_sun]
MaxLogMass_noMassLoss (FLOAT): Maximum stellar mass (upper 68% confidence level of logmass) without mass loss [in log M_sun]
MedianPDF_noMassLoss (FLOAT): Median value of the logmass PDF without mass loss [in log M_sun]
PDF16_noMassLoss (FLOAT): Value of PDF at which 16% of the logmass probability is accumulated without mass loss [in log M_sun]
PDF84_noMassLoss (FLOAT): Value of PDF at which 84% of the logmass probability is accumulated without mass loss [in log M_sun]
PeakPDF_noMassLoss (FLOAT): Peak value of logmass PDF without mass loss [in log M_sun]
ReducedChi2 (FLOAT): Reduced chi squared of best fit
Age (FLOAT): Best-fit age of galaxy [in Gyr]
MinAge (FLOAT): Minimum age (lower confidence level of age) [in Gyr]
MaxAge (FLOAT): Maximum age (upper confidence level of age) [in Gyr]
SFR (FLOAT): Star formation rate of best fit [in M_sun/yr]
MinSFR (FLOAT): Minimum star formation rate (lower confidence level of SFR) [in M_sun/yr]
MaxSFR (FLOAT): Maximum star formation rate (upper confidence level of SFR) [in M_sun/yr]
AbsMagK (FLOAT): Absolute magnitude in K-band
SFH (STRING): Star formation history of best fit template
Metallicity (STRING): Metallicity of best fit template:

Starforming Model:	One of '0.004', '0.01', '0.02', or '0.04' [where Z_sun=0.02]
Passive Model:	'COMPOSITE' (Z=0.02 + 3% (in mass) of old metal-poor stars)

NFilter (LONG): Number of filters used in the fit (default is 5 for ugriz)
ReddeningLaw (LONG): ID of best fit reddening law (0 = no reddening)
BOSS_TARGET1 (LONG64): See BOSS_TARGET
ANCILLARY_TARGET1 (LONG64): See ANCILLARY_TARGET
ANCILLARY_TARGET2 (LONG64): See ANCILLARY_TARGET
SPECPRIMARY (BYTE): Objects observed multiple times will have this set to 1 for one observation only. This is usually the 'best'.
SPECOBJID (LONG64): CAS-style spectroscopic object identifier.