Browse
this table...

SDSSDR7WD - Sloan Digital Sky Survey DR7 White Dwarf Catalog

HEASARC
Archive

Overview

This table contains a new catalog of spectroscopically confirmed white dwarf stars from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) spectroscopic catalog. The authors find 20,407 white dwarf spectra, representing 19,712 stars, and provide atmospheric model fits to 14,120 DA and 1011 DB white dwarf spectra from 12,843 and 923 stars, respectively. These numbers represent more than a factor of two increase in the total number of white dwarf stars from the previous SDSS white dwarf catalogs based on DR4 data. The distribution of subtypes varies from previous catalogs due to the authors' more conservative, manual classifications of each star in our catalog, supplementing their automatic fits. In particular, they find a large number of magnetic white dwarf stars whose small Zeeman splittings mimic increased Stark broadening that would otherwise result in an overestimated log g if fit as a non-magnetic white dwarf. The authors calculate mean DA and DB masses for their clean, non-magnetic sample and find the DB mean mass is statistically larger than that for the DAs.

This table lists the 20,407 white dwarf spectra corresponding to 19,712 distinct stars.


Catalog Bibcode

2013ApJS..204....5K

References

SDSS DR7 White Dwarf Catalog
    Kleinman S.J., Kepler S.O., Koester D., Pelisoli I., Pecanha V., Nitta A.,
    Costa J.E.S., Krzesinski J., Dufour P., Lachapelle F.-R., Bergeron P.,
    Yip C.-W., Harris H.C., Eisenstein D.J., Althaus L., Corsico A.
   <Astrophys. J. Suppl., 204, article id. 5, 14 pp. (2013).>
   =2013ApJS..204....5K

Provenance

This table was created by the HEASARC in January 2013 based on the electronic version of Table 2 from the reference paper which was obtained from the ApJS web site.

Parameters

Name
The SDSS DR7 IAU-style name for the white dwarf, using the 'SDSS J' prefix and the J2000 coordinates, viz. 'SDSS JHHMMSS.ssdDDMMSS.s'. Because of tiny astrometry shifts, it is possible that this name may differ from the name in previous SDSS releases. This breaks the IAU convention that published names never change. It is strongly recommended that associations be performed on the positional coordinates rather than on the names.

Plate_Number
The SDSS spectroscopic plate number

Spectrum_Date
The date of the SDSS spectroscopic observation for the white dwarf.

Fiber_Number
The fiber number of the SDSS spectroscopic observation for the white dwarf.

RA
The Right Ascension of the white dwarf in the selected equinox (given in J2000 decimal degree coordinates and to a precision of 10-8 - 10-6 degrees in the original table). The epoch of the coordinates is given by the time of the SDSS imaging observation as specified in the value of the imaging_date parameter.

Dec
The Declination of the white dwarf in the selected equinox (given in J2000 decimal degree coordinates and to a precision of 10-8 - 10-6 degrees in the original table). The epoch of the coordinates is given by the time of the SDSS imaging observation as specified in the value of the imaging_date parameter.

LII
The Galactic Longitude of the white dwarf.

BII
The Galactic Latitude of the white dwarf.

Gmag_SNR
The SDSS g-band signal-to-noise ratio of the white dwarf.

Umag
The SDSS u-band PSF magnitude of the white dwarf.

Umag_Error
The uncertainty in the SDSS u-band PSF magnitude of the white dwarf.

Umag_Flag
The photometrc flag value for the SDSS u-band PSF magnitude of the white dwarf. The photometric flag values are processed versions of the flagsband parameter in the SDSS database. It has been logically ANDed with the appropriate values to highlight objects that have the following quality control flags set: EDGE, PEAKCENTER, NOPROFILE, BAD_COUNTS_ERROR, INTERP_CENTER, DEBLEND_NOPEAK, PSF_FLUX_INTERP, SATURATED, and NOTCHECKED. If the value is non-zero, then the corresponding SDSS magnitude is suspect.

Gmag
The SDSS g-band PSF magnitude of the white dwarf.

Gmag_Error
The uncertainty in the SDSS g-band PSF magnitude of the white dwarf.

Gmag_Flag
The photometrc flag value for the SDSS g-band PSF magnitude of the white dwarf. The photometric flag values are processed versions of the flagsband parameter in the SDSS database. It has been logically ANDed with the appropriate values to highlight objects that have the following quality control flags set: EDGE, PEAKCENTER, NOPROFILE, BAD_COUNTS_ERROR, INTERP_CENTER, DEBLEND_NOPEAK, PSF_FLUX_INTERP, SATURATED, and NOTCHECKED. If the value is non-zero, then the corresponding SDSS magnitude is suspect.

Rmag
The SDSS r-band PSF magnitude of the white dwarf.

Rmag_Error
The uncertainty in the SDSS r-band PSF magnitude of the white dwarf.

Rmag_Flag
The photometrc flag value for the SDSS r-band PSF magnitude of the white dwarf. The photometric flag values are processed versions of the flagsband parameter in the SDSS database. It has been logically ANDed with the appropriate values to highlight objects that have the following quality control flags set: EDGE, PEAKCENTER, NOPROFILE, BAD_COUNTS_ERROR, INTERP_CENTER, DEBLEND_NOPEAK, PSF_FLUX_INTERP, SATURATED, and NOTCHECKED. If the value is non-zero, then the corresponding SDSS magnitude is suspect.

Imag
The SDSS i-band PSF magnitude of the white dwarf.

Imag_Error
The uncertainty in the SDSS i-band PSF magnitude of the white dwarf.

Imag_Flag
The photometrc flag value for the SDSS i-band PSF magnitude of the white dwarf. The photometric flag values are processed versions of the flagsband parameter in the SDSS database. It has been logically ANDed with the appropriate values to highlight objects that have the following quality control flags set: EDGE, PEAKCENTER, NOPROFILE, BAD_COUNTS_ERROR, INTERP_CENTER, DEBLEND_NOPEAK, PSF_FLUX_INTERP, SATURATED, and NOTCHECKED. If the value is non-zero, then the corresponding SDSS magnitude is suspect.

Zmag
The SDSS z-band PSF magnitude of the white dwarf.

Zmag_Error
The uncertainty in the SDSS z-band PSF magnitude of the white dwarf.

Zmag_Flag
The photometrc flag value for the SDSS z-band PSF magnitude of the white dwarf. The photometric flag values are processed versions of the flagsband parameter in the SDSS database. It has been logically ANDed with the appropriate values to highlight objects that have the following quality control flags set: EDGE, PEAKCENTER, NOPROFILE, BAD_COUNTS_ERROR, INTERP_CENTER, DEBLEND_NOPEAK, PSF_FLUX_INTERP, SATURATED, and NOTCHECKED. If the value is non-zero, then the corresponding SDSS magnitude is suspect.

PM_Tot
The SDSS proper motion of the white dwarf, in mas/year. This was converted by the HEASARC from the units of 0.01 arcsec/yr used in the original version.

PM_PA
The SDSS proper motion angle, in degrees (measured from N through E).

PM_Match_Flag
The SDSS proper motion match flag, where a value of 1 means that there was a successful match within 1.0 arcsec.

Gmag_Extinction
The extinction in the g band, Ag, in magnitudes.

Imaging_Date
The date and time of the imaging observation for the white dwarf when row 0 of r measurements was read.

Autofit_Spect_Type
The autofit spectral type classification of the white dwarf.

Autofit_Eff_Temp
The autofit effective temperature of the white dwarf, in Kelvin.

Autofit_Eff_Temp_Error
The uncertainty in the autofit effective temperature of the white dwarf, in Kelvin.

Autofit_Log_G
The autofit logarithm of the surface gravity of the white dwarf, in cm s-2.

Autofit_Log_G_Error
The uncertainty in the autofit logarithm of the surface gravity of the white dwarf, in cm s-2.

Autofit_Red_Chisquared
The autofit reduced chi2 of the fit to the spectrum of the white dwarf.

Unique_Flag
The 'unique number' of the spectrum for the specific white dwarf. This is assigned to identify duplicate spectra of the same object. For objects with only one spectrum, the value of this parameter is 'uniq'. For objects with more than one spectrum, the value will be dup-xxxx where xxxx is a running number, the same for all spectra of the same object. The spectrum with the highest signal-to-noise ratio for objects with duplicate spectra will be identified with an a at the end of its dup-xxxx name.

Mass
The calculated mass of the white dwarf, in solar masses, given for clean DAs and DBs only. This is calculated as described on Section 6.2 of the reference paper.

Mass_Error
The uncertainty in the calculated mass of the white dwarf, in solar masses.

Spect_Type
The 'human' spectral type classification assigned to the spectrum.

Class
The HEASARC Browse object classification, based on the 'human' spectral type classification (the spect_type parameter value).


Contact Person

Questions regarding the SDSSDR7WD database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 11-Jan-2013