DEEP2 DR3 zcat Primer

Redshift and velocity dispersions for each DEEP2 spectroscopic target are measured utilizing a data analysis pipeline and then checked individually by eye. Like the spec2d DEIMOS pipeline, the redshift code was developed by the DEEP2 team at UCB and is entirely written in IDL. For a basic description of the redshift code, refer to the redshift pipeline notes.

All of the DEEP2 redshifts and spectra were inspected by at least one human eye and a Quality code (Q=-2 through Q=4) was assigned to the best-fitting redshift. The DEEP2 redshift quality codes are explained in detail here and in Davis et al. 2007.

The DR3 redshift catalog can be read from file using the mrdfits IDL routine like so:

IDL> zcat = mrdfits('zcat.dr3.fits.gz', 1)

For a brief introduction to reading FITS files and BINTABLES in IDL, refer to the photometry reference page included in DR1, here.

The DEEP2 DR3 redshift catalog structures contain 24 tags for each object with 50,386 entries in the entire catalog (47,700 unique objects). In detail, the tags or fields are as follows:

Tag Name	Date Type	Description
OBJNO	Long	DEEP2 object number
RA	Double	Right Ascension (in decimal degrees, J2000)
DEC	Double	Declination (in decimal degrees, J2000)
MAGB	Float	CFHT B magnitude
MAGR	Float	CFHT R magnitude
MAGI	Float	CFHT I magnitude
PGAL	Float	the probability that the source is a galaxy for unresolved sources, 3 if resolved
SFD_EBV	Float	E(B-V) from Schlegel, Finkbeiner, and Davis dust map
CLASS	STRING	type of best-fitting template (e.g. GALAXY or STAR)
SUBCLASS	STRING	coarse classification for stars
OBJNAME	STRING	the 8-digit DEEP2 object id (same as objno)
MASKNAME	Float	the DEEP2 slitmask number on which the object was observed
SLITNAME	STRING	the slitlet number (on mask MASKNAME) in which the object was placed
DATE	STRING	date that the object was observed
MJD	Float	Modified Julian Date of observation
Z	Float	observed best-fitting redshift
ZHELIO	Float	redshift corrected for heliocentric motion
Z_ERR	Float	redshift error
RCHI2	Float	reduced chi-squared value for the redshift fit
DOF	Long	degrees of freedom for redshift fit
VDISP	Float	velocity dispersion in km/s
VDISP_ERR	Float	error in velocity dispersion
ZQUALITY	Int	redshift quality code; for explanation of codes, take a look here.
COMMENT	String	comment field; for more details on comment strings, take a look here.

For more information on the MAGB, MAGR, MAGI, PGAL, and SFD_EBV tags, refer to the documentation for the photometric catalogs.

created by M. Cooper
last updated 2007aug01