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TWOMASSRSC - 2MASS Redshift Survey (2MRS) Catalog

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Overview

This table is based on the results of the 2MASS Redshift Survey (2MRS), a ten-year project to map the full three-dimensional distribution of galaxies in the nearby universe. The Two Micron All Sky Survey (2MASS) was completed in 2003 and its final data products, including an extended source catalog (XSC), are available online. The 2MASS XSC contains nearly a million galaxies with Ks <= 13.5 mag and is essentially complete and mostly unaffected by interstellar extinction and stellar confusion down to a galactic latitude of |b| = 5 degrees for bright galaxies. Near-infrared wavelengths are sensitive to the old stellar populations that dominate galaxy masses, making 2MASS an excellent starting point to study the distribution of matter in the nearby universe. The authors selected a sample of 44,599 2MASS galaxies with Ks <= 11.75 mag and |b| >= 5 degrees (>= 8 degrees toward the Galactic bulge) as the input catalog for their survey. They obtained spectroscopic observations for 11,000 galaxies and used previously obtained velocities for the remainder of the sample to generate a redshift catalog that is 97.6% complete to well-defined limits and covers 91% of the sky. This provides an unprecedented census of galaxy (baryonic mass) concentrations within 300 Mpc. Earlier versions of their survey have been used in a number of publications that have studied the bulk motion of the Local Group, mapped the density and peculiar velocity fields out to 50 h-1 Mpc, detected galaxy groups, and estimated the values of several cosmological parameters. Additionally, the authors present morphological types for a nearly complete sub-sample of 20,860 galaxies with Ks <= 11.25 mag and |b| >= 10 degrees.

The authors initially selected 45,086 sources which met the following criteria:

    Ks <= 11.75 mag and detected at H,
    E(B - V) <= 1 mag,
    |b| >= 5 degrees for 30 degrees < l < 330 degrees,
    |b| >= 8 degrees otherwise.
They rejected 324 sources of galactic origin (multiple stars, planetary nebulae, and H II regions) or pieces of galaxies detected as separate sources by the 2MASS pipeline. Additionally, they flagged 314 bona fide galaxies with compromised photometry for reprocessing at a future date. Some of these galaxies have bright stars very close to their nuclei which were not detected by the pipeline. Others are in regions of high stellar density and their center positions and/or isophotal radii have been incorrectly measured by the pipeline. Lastly, some are close pairs or multiples but the pipeline only identified a single object. A detailed explanation of the steps taken to reject and reprocess the flagged galaxies is given in the Appendix of the reference paper.

In summary, the final input catalog contained here has 44,599 entries (plotted using black symbols in Figure 1 of the reference paper). In this table, redshifts for 43,533 of the selected galaxies, or 97.6% of the sample, are presented.


Catalog Bibcode

2012ApJS..199...26H

References

The 2MASS Redshift Survey - Description and Data Release
         Huchra J.P., Macri L.M., Masters K.L., Jarrett T.H., Berlind P.,
         Calkins M., Crook A.C., Cutri R., Erdogdu P., Falco E., George T.,
         Hutcheson C.M., Lahav O., Mader J., Mink J.D., Martimbeau N.,
         Schneider S., Skrutskie M., Tokarz S., Westover M.
        <Astrophys. J. Suppl. 199, 26 (2012)>

Provenance

This table was created by the HEASARC in April 2012 based on an electronic version of Table 3 of the reference paper which was obtained from the ApJS website.

Parameters

Name
The 2MASS identification for the galaxy taken from the 2MASS Extended Source Catalog (XSC: Jarrett et al. 2000, AJ, 119, 2498 and Jarrett 2004, PASA, 21, 396) or the 2MASS Large Galaxy Atlas (LGA: Jarrett et al. 2003, AJ, 125, 525) databases.

RA
The Right Ascension of the galaxy in the selected equinox. This was given in J2000.0 equatorial coordinates in decimal degrees to a precision of 10-5 degrees in the original reference table.

Dec
The Declination of the galaxy in the selected equinox. This was given in J2000.0 equatorial coordinates in decimal degrees to a precision of 10-5 degrees in the original reference table.

LII
The Galactic Longitude of the galaxy.

BII
The Galactic Latitude of the galaxy.

Ks_Mag_0
The extinction-corrected isophotal Ks magnitude of the galaxy measured in an elliptical aperture defined at the Ks = 20 magnitudes per square arcsecond isophote. The modest extinction correction that was applied to the 2MASS XSC or LGA magnitudes was based on the maps of Schlegel et al. (1998, ApJ, 500, 525).

Ks_Mag_0_Error
The uncertainty in the value of the corresponding magnitude.

Hmag_0
The extinction-corrected isophotal H magnitude of the galaxy measured in an elliptical aperture defined at the Ks = 20 magnitudes per square arcsecond isophote. The modest extinction correction that was applied to the 2MASS XSC or LGA magnitudes was based on the maps of Schlegel et al. (1998, ApJ, 500, 525).

Hmag_0_Error
The uncertainty in the value of the corresponding magnitude.

Jmag_0
The extinction-corrected isophotal J magnitude of the galaxy measured in an elliptical aperture defined at the Ks = 20 magnitudes per square arcsecond isophote. The modest extinction correction that was applied to the 2MASS XSC or LGA magnitudes was based on the maps of Schlegel et al. (1998, ApJ, 500, 525). Values of this parameter of 99.999 in the original table were turned to nulls in the HEASARC version of this table.

Jmag_0_Error
The uncertainty in the value of the corresponding magnitude. Values of this parameter of 9.999 in the original table were turned to nulls in the HEASARC version of this table.

Ks_Mag_0_Tot
The extinction-corrected "total" extraoplated Ks magnitude of the galaxy as derived by the 2MASS photometric pipeline. The modest extinction correction that was applied to the 2MASS XSC or LGA magnitudes was based on the maps of Schlegel et al. (1998, ApJ, 500, 525).

Ks_Mag_0_Tot_Error
The uncertainty in the value of the corresponding magnitude.

Hmag_0_Tot
The extinction-corrected "total" extraoplated H magnitude of the galaxy as derived by the 2MASS photometric pipeline. The modest extinction correction that was applied to the 2MASS XSC or LGA magnitudes was based on the maps of Schlegel et al. (1998, ApJ, 500, 525).

Hmag_0_Tot_Error
The uncertainty in the value of the corresponding magnitude. Values of this parameter of 9.999 in the original table were turned to nulls in the HEASARC version of this table.

Jmag_0_Tot
The extinction-corrected "total" extraoplated J magnitude of the galaxy as derived by the 2MASS photometric pipeline. The modest extinction correction that was applied to the 2MASS XSC or LGA magnitudes was based on the maps of Schlegel et al. (1998, ApJ, 500, 525).

Jmag_0_Tot_Error
The uncertainty in the value of the corresponding magnitude. Values of this parameter of 9.999 in the original table were turned to nulls in the HEASARC version of this table.

Reddening
The foreground Galactic reddening E(B-V), in magnitudes, towards the galaxy, based on the maps of Schlegel et al. (1998, ApJ, 500, 525).

Log_K20_Semimajor_Axis
The logarithm of the Ks = 20 mag arcsec-2 elliptical isophote's semi-major axis of the galaxy, in arcseconds.

Log_Tot_Semimajor_Axis
The logarithm of the "total magnitude" extraopolation semi-major axis of the galaxy, in arcseconds.

Axis_Ratio
The axial ratio, b/a, of the (J + H + Ks) co-added image of the galaxy at the 3-sigma isophote. Values of this parameter of 9.999 in the original table were turned to nulls in the HEASARC version of this table.

Xsc_Ppc_Flags
The 2MASS XSC database pipeline photometry confusion flags for the galaxy (cc_flg, k_flg_k20fe, h_flg_k20fe, j_flg_20kfe). "Z" in the first character indicates that the magnitudes are from the 2MASS LGA.

Morph_Type
The morphological type of the galaxy, expressed using the ZCAT convention as discussed in Section 5 and Table 5 of the reference paper. It is a five digit code (I2, A1, I1, and A1). The first two digits are the numerically coded T type, the next letter (if present) is the Bar type, the next digit (if present) is the numerically coded luminosity class, and the final letter (if present) denotes morphological perculiarities.

The allowed T types are:

  -9       QSO/AGN
  -7       Unclassified Elliptical
  -6       Compact Elliptical
  -5       E, and dwarf E
  -4       E/SO
  -3       L-, SO-
  -2       L, SO
  -1       L+, SO+
   0       SO/a, SO-a
   1       Sa
   2       Sab
   3       Sb
   4       Sbc
   5       Sc
   6       Scd
   7       Sd
   8       Sdm
   9       Sm
  10       Im, Irr I, Magellanic Irregular, Dwarf Irregular
  11       Compact Irregular, Extragalactic H ii Region
  12       Extragalactic H i cloud (no galaxy visible)
  15       Peculiar, Unclassifiable
  16       Irr II
  19       Unclassified galaxy (visually confirmed to be a galaxy, but not typed)
  20       S..., Sc-Irr, Unclassified Spiral
  98       Galaxy that has never been visually examined.
  
The luminosity classes (for spirals & irregulars) are:
  1       I
  2       I-II
  3       II
  4       II-II
  5       III
  6       III-IV
  7       IV
  8       IV-V
  9       V
  
The allowed bar types are:
  A       unbarred (A)
  X       mixed type (AB)
  B       barred (B)
  
The peculiarities are:
  D       Double or Multiple
  P       Peculiar
  R       Outer Ring
  r       Inner Ring
  s       S-shaped
  t       Mixed (Inner ring/S-shaped)
  T       Pseudo outer ring
  /       Spindle
  

Ref_Morph_Type
The coded source of the galaxy morphological type as follows:

     JH = newly typed galaxy by John Huchra
     ZC = previously listed in ZCAT (from multiple sources)
     NN = not available
  

Radial_Velocity
The solar system barycenter reference frame "redshift" (radial velocity) of the galaxy, in km s-1.

Radial_Velocity_Error
The uncertainty in the solar system barycenter reference frame "redshift" (radial velocity) of the galaxy, in km s-1.

Radial_Velocity_Source
The source for the "redshift" (radial velocity) of the galaxy coded as follows:

        C = CTIO
        D = McDonald
        F = FLWO
        M = alternative NED redshift
        N = default NED redshift
        O = ZCAT
        S = SDSS-DR8
        6 = 6dFGS-DR3
  

Ref_Radial_Velocity
The NED bibliographic code for the source of the radial velocity taken from one of the 578 references listed in Table 4 of the reference paper. The authors strongly encourage proper citation of the original publications when making use of any of these values.

Alt_Name
The galaxy identification in the input redshift catalog.


Contact Person

Questions regarding the TWOMASSRSC database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 24-Apr-2012