2MASS Galaxy Redshift Catalog

2MASS Galaxy Redshift Catalog (XSCz)

XSCz Statistics

The XSC contains over 1.5 million galaxies, extending down to J=15.3 mag and K = 14.1 mag for S/N > 7 in any given band. Most XSC galaxies are faint and small (higher redshift), rendering photometric redshifts unreliable for S/N < 10. Consequently, the XSCz is K-band limited to K=14th mag to improve reliability of the photometric redshifts at the faint end. With this cut, the sample is 1.15 million galaxies, of which over 300,000 have radial velocities or other well determined distances. Most of the redshifts come from the ZCAT & 2MRS (Huchra), 6dFGS and the SDSS; tabulated below.

Total XSC sources: 1,634,126

XSC with K < 14 mag 1,145,352

Total photometric redshifts: 833,611 (73% of XSCz)
Total radial velocities: 311,741 (27% of XSCz)
ZCAT redshifts: 193,365
2MRS redshifts: 24,376
6dFGS redshifts: 117,291
SDSS redshifts: 100,293
2dF redshifts: 43,942
Tully BGC: 2,952
Misc NED redshifts: 92,912
Misc LEDA redshifts: 24,182

NED-1D: Cepheid/T-F/SBF Distances: 1068

Finger-of-God Corrected redshifts: 7,880

Note that the itemized redshift catalogs are not exclusive; e.g., a galaxy may have a redshift measured by SDSS but is also found in ZCAT. For a small subset of nearby galaxies, accurate distances from Cepheid, Tully-Fisher, Surface Brightness Fluctuations, etc, are used instead of redshifts; the information comes from the NED-1D table. For 4-D visualization of the XSCz (see below), large galaxy clusters are corrected for the finger-of-god radial velocity artifact, as described in the document. For M* (K-band) = -24 mag, the effective redshift is 0.094 for K=14th mag.

Redshift Statistics:

redshift range total number of sources photometric
redshifts (%total) photo(z) unc. radial velocity
redshifts number per volume
100 per Mpc^3

0 to 0.01 5,557 125 ( 2.2%) 33.3 (%) 5,557 (97.8%) 1.918
0.01 to 0.02 17,109 784 (4.6%) 34.6 (%) 16,325 (95.4%) 0.846
0.02 to 0.03 29,011 3,687 (12.7%) 31.8 (%) 25,324 (87.3%) 0.544
0.03 to 0.04 46,839 15,540 (33.2%) 26.7 (%) 31,299 (66.8%) 0.464
0.04 to 0.05 63,618 33,758 (53.1%) 36.8 (%) 29,860 (46.9%) 0.393
0.05 to 0.06 97,669 65,655 (67.2%) 34.8 (%) 32,014 (32.8%) 0.416
0.06 to 0.07 127,377 96,575 (75.8%) 29.6 (%) 30,802 (24.2%) 0.400
0.07 to 0.08 149,715 122,208 (81.6%) 25.8 (%) 27,507 (18.4%) 0.364
0.08 to 0.09 144,302 122,224 (84.7%) 31.4 (%) 22,078 (15.3%) 0.281
0.09 to 0.10 126,839 110,346 (87.0%) 34.3 (%) 16,493 (13.0%) 0.203
0.10 to 0.12 174,120 147,775 (84.9%) 33.7 (%) 26,345 (15.1%) 0.108
0.12 to 0.14 90,399 72,475 (80.2%) 31.5 (%) 17,924 (19.8%) 0.042
0.14 to 0.16 41,466 30,018 (72.4%) 29.0 (%) 11,448 (27.6%) 0.015
0.16 to 0.18 18,831 12,272 (65.2%) 32.1 (%) 6,559 (34.83%) 0.006
0.18 to 0.20 7.954 3,511 (44.1%) 21.8 (%) 4,443 (55.86%) 0.003
>0.20 4,420 807 (18.3%) -- 3,613 (81.74%) --

Redshift distribution of the XSCz with radial velocity measurements.
Luminosity distribution of the XSCz with radial velocity measurements.

Size Distribution w/ redshift. Physical radius (kpc) based on the K=20 mag/arcsec² isophotal radius.
Size Distribution w/ M_K. Physical radius (kpc) based on the K=20 mag/arcsec² isophotal radius.

main

Introduction

Spectroscopic Redshifts

Photometric Redshifts

Finger-of-God Artifacts

Visualization Partiview

Links References

Page last updated May 8, 2007.

Total XSC sources:	1,634,126
XSC with K < 14 mag	1,145,352
Total photometric redshifts:	833,611 (73% of XSCz)
Total radial velocities:	311,741 (27% of XSCz)
ZCAT redshifts:	193,365
2MRS redshifts:	24,376
6dFGS redshifts:	117,291
SDSS redshifts:	100,293
2dF redshifts:	43,942
Tully BGC:	2,952
Misc NED redshifts:	92,912
Misc LEDA redshifts:	24,182
NED-1D: Cepheid/T-F/SBF Distances:	1068
Finger-of-God Corrected redshifts:	7,880

redshift range	total number of sources	photometric redshifts (%total)	photo(z) unc.	radial velocity redshifts	number per volume 100 per Mpc^3
0 to 0.01	5,557	125 ( 2.2%)	33.3 (%)	5,557 (97.8%)	1.918
0.01 to 0.02	17,109	784 (4.6%)	34.6 (%)	16,325 (95.4%)	0.846
0.02 to 0.03	29,011	3,687 (12.7%)	31.8 (%)	25,324 (87.3%)	0.544
0.03 to 0.04	46,839	15,540 (33.2%)	26.7 (%)	31,299 (66.8%)	0.464
0.04 to 0.05	63,618	33,758 (53.1%)	36.8 (%)	29,860 (46.9%)	0.393
0.05 to 0.06	97,669	65,655 (67.2%)	34.8 (%)	32,014 (32.8%)	0.416
0.06 to 0.07	127,377	96,575 (75.8%)	29.6 (%)	30,802 (24.2%)	0.400
0.07 to 0.08	149,715	122,208 (81.6%)	25.8 (%)	27,507 (18.4%)	0.364
0.08 to 0.09	144,302	122,224 (84.7%)	31.4 (%)	22,078 (15.3%)	0.281
0.09 to 0.10	126,839	110,346 (87.0%)	34.3 (%)	16,493 (13.0%)	0.203
0.10 to 0.12	174,120	147,775 (84.9%)	33.7 (%)	26,345 (15.1%)	0.108
0.12 to 0.14	90,399	72,475 (80.2%)	31.5 (%)	17,924 (19.8%)	0.042
0.14 to 0.16	41,466	30,018 (72.4%)	29.0 (%)	11,448 (27.6%)	0.015
0.16 to 0.18	18,831	12,272 (65.2%)	32.1 (%)	6,559 (34.83%)	0.006
0.18 to 0.20	7.954	3,511 (44.1%)	21.8 (%)	4,443 (55.86%)	0.003
>0.20	4,420	807 (18.3%)	--	3,613 (81.74%)	--

Redshift distribution of the XSCz with radial velocity measurements.	Luminosity distribution of the XSCz with radial velocity measurements.
Size Distribution w/ redshift. Physical radius (kpc) based on the K=20 mag/arcsec² isophotal radius.	Size Distribution w/ M_K. Physical radius (kpc) based on the K=20 mag/arcsec² isophotal radius.