J/MNRAS/411/2770 Hot white dwarfs in GALEX-DR5 (Bianchi+, 2011)
Catalogues of hot white dwarfs in the Milky way from GALEX's ultraviolet sky surveys: constraining stellar evolution. Bianchi L., Efremova B., Herald J., Girardi L., Zabot A., Marigo P., Martin C. <Mon. Not. R. Astron. Soc., 411, 2770-2791 (2011)> =2011MNRAS.411.2770B
ADC_Keywords: Stars, blue ; Ultraviolet ; Stars, white dwarf Keywords: catalogues ; surveys ; stars: evolution ; white dwarfs ; Galaxy: stellar content ; ultraviolet: stars Abstract: We present comprehensive catalogues of hot star candidates in the Milky Way (MW), selected from Galaxy Evolution Explorer (GALEX) far-UV (FUV; 1344-1786Å) and near-UV (NUV; 1771-2831Å) imaging. The FUV and NUV photometry allows us to extract the hottest stellar objects, in particular hot white dwarfs (WD), which are elusive at other wavelengths because of their high temperatures and faint optical luminosities. We generated catalogues of UV sources from two GALEX's surveys: All-Sky Imaging Survey (AIS; depth AB magnitude ∼19.9/20.8 in FUV/NUV) and Medium-depth Imaging Survey (MIS; depth ∼22.6/22.7mag). The two catalogues (from GALEX fifth data release) contain 65.3/12.6 million (AIS/MIS) unique UV sources with errorNUV≤ 0.5 mag, over 21 435/1579deg2. We also constructed subcatalogues of the UV sources with matched optical photometry from Sloan Digital Sky Survey (SDSS; seventh data release): these contain 0.6/0.9 million (AIS/MIS) sources with errors ≤0.3mag in both FUV and NUV, excluding sources with multiple optical counterparts, over an area of 7325/1103 deg2. All catalogues are available online. We then selected 28 319 (AIS)/9028 (MIS) matched sources with FUV-NUV←0.13; this colour cut corresponds to stellar Teff hotter than ∼18 000K (the exact value varying with gravity). An additional colour cut of NUV-r>0.1 isolates binaries with largely differing Teffs, and some intruding quasi-stellar objects (QSOs; more numerous at faint magnitudes). Available spectroscopy for a subsample indicates that hot-star candidates with NUV-r<0.1 (mostly 'single' hot stars) have negligible contamination by non-stellar objects. We discuss the distribution of sources in the catalogues, and the effects of error and colour cuts on the samples. The density of hot-star candidates increases from high to low Galactic latitudes, but drops on the MW plane due to dust extinction. Our hot-star counts at all latitudes are better matched by MW models computed with an initial-final mass relation (IFMR) that favours lower final masses. The model analysis indicates that the brightest sample is likely composed of WDs located in the thin disc, at typical distances between 0.15 and 1kpc, while the fainter sample comprises also a fraction of thick disc and halo stars. Proper motion distributions, available only for the bright sample (NUV<18mag), are consistent with the kinematics of a thin-disc population. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file gr5-ais.dat 228 28333 *Catalog of hot star candidates, from All-Sky Imaging Survey, GALEX-AIS-SDSS (FUV≤20) gr5-mis.dat 228 9032 *Catalog of hot star candidates, from Medium-depth Imaging Survey, GALEX-MIS-SDSS
Note on gr5-ais.dat, gr5-mis.dat: only sources with "rank=0" included, i.e. UV sources with one SDSS counterpart (within the match radius of 3"), see paper for more details.
See also: ftp://archive.stsci.edu/pub/hlsp/bianchi_gr5xdr7 : GALEX-GR5 Home Page Byte-by-byte Description of file: gr5-ais.dat gr5-mis.dat
Bytes Format Units Label Explanations
1- 19 A19 --- IAU GALEX ID following the IAU convention, JHHMMSS.ss+DDMMSS.s 21- 39 A19 --- GALEX GALEX ID 41- 51 F11.6 deg RAdeg Right ascension (J2000) 53- 63 F11.6 deg DEdeg Declination (J2000) 65- 75 F11.6 deg GLON Galactic longitude 77- 87 F11.6 deg GLAT Galactic latitude 89-107 A19 --- SDSS SDSS designation 109-111 F3.1 arcsec Dist Distance between the GALEX and SDSS source 113-117 F5.2 mag FUV GALEX FUV magnitude (AB mag) 119-123 F5.2 mag e_FUV GALEX FUV magnitude error 125-129 F5.2 mag NUV GALEX NUV magnitude (AB mag) 131-135 F5.2 mag e_NUV GALEX NUV magnitude error 137-141 F5.2 mag umag SDSS u magnitude (AB mag) 143-147 F5.2 mag e_umag ?=89 SDSS u magnitude error (1) 149-153 F5.2 mag gmag SDSS g magnitude (AB mag) 155-159 F5.2 mag e_gmag ?=89 SDSS g magnitude error (1) 161-165 F5.2 mag rmag SDSS r magnitude (AB mag) 167-171 F5.2 mag e_rmag ?=89 SDSS r magnitude error (1) 173-177 F5.2 mag imag SDSS i magnitude (AB mag) 179-183 F5.2 mag e_imag ?=89 SDSS i magnitude error (1) 185-189 F5.2 mag zmag SDSS z magnitude (AB mag) 191-195 F5.2 mag e_zmag ?=89 SDSS z magnitude error (1) 197-201 F5.2 mag E(B-V) E(B-V) from Schlegel maps at the source position 203-205 I3 --- f_NUV NUV artifact flag from GALEX pipeline 207 I1 --- n_IAU [0/1] Flag set to 1 for sources with (NUV-r)<0.1 (single star candidates) 209-228 A20 --- SpecId SDSS Spectrum ID (0 if no SDSS spectrum exists)
Note (1): Sources saturated in an SDSS band have their errors set to 89, those not detected in an SDSS band have their errors set to 99.
History: Copied at ftp://archive.stsci.edu/pub/hlsp/bianchi_gr5xdr7
(End) Patricia Vannier [CDS] 30-Mar-2011
|The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line|