J/ApJ/725/1215 Faint UV standards from Swift, GALEX and SDSS (Siegel+, 2010)
Faint Near-ultraviolet/Far-ultraviolet standards from Swift/UVOT, GALEX, and
SDSS photometry.
Siegel M.H., Hoversten E.A., Roming P.W.A., Landsman W.B.,
Allende Prieto C., Breeveld A.A., Brown P., Holland S.T., Kuin N.P.M.,
Page M.J., Vanden Berk D.E.
<Astrophys. J., 725, 1215-1225 (2010)>
=2010ApJ...725.1215S 2010ApJ...725.1215S
ADC_Keywords: Stars, white dwarf ; Photometry, ultraviolet ; Photometry, SDSS ;
Models
Keywords: techniques: photometric - ultraviolet: general - ultraviolet: stars -
white dwarfs
Abstract:
At present, the precision of deep ultraviolet photometry is somewhat
limited by the dearth of faint ultraviolet standard stars. In an
effort to improve this situation, we present a uniform catalog of 11
new faint (u∼17) ultraviolet standard stars. High-precision photometry
of these stars has been taken from the Sloan Digital Sky Survey and
Galaxy Evolution Explorer archives and combined with new data from the
Swift Ultraviolet Optical Telescope to provide precise photometric
measures extending from the near-infrared to the far-ultraviolet.
These stars were chosen because they are known to be hot
(20000<Teff<50000K) DA white dwarfs with published Sloan spectra
that should be photometrically stable. This careful selection allows
us to compare the combined photometry and Sloan spectroscopy to models
of pure hydrogen atmospheres to both constrain the underlying
properties of the white dwarfs and test the ability of white dwarf
models to predict the photometric measures.
Description:
We supplemented the existing GALEX and SDSS photometry for the DA
white dwarfs (from Eisenstein et al. 2006, Cat. J/ApJS/167/40) with a
new epoch of photometry from the UVOT instrument aboard the Swift
Gamma Ray Burst Mission. Eleven of our 12 target stars were observed
as fill-in targets during the 2008-2009 Swift AO4 observing cycle.
Data were taken in the u, uvw1, uvm2, and uvw2 filters between 2008
June and 2009 February. A handful of stars were re-observed in 2009
June for additional calibration.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 81 11 Swift/GALEX/SDSS UV standard stars and model
parameters
table3.dat 107 11 Swift UVOT and GALEX photometry of faint UV
standards (AB mags)
table8.dat 38 220011 Model flux for WD standards
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See also:
II/306 : The SDSS Photometric Catalog, Release 8 (Adelman-McCarthy+, 2011)
III/235 : Spectroscopically Identified White Dwarfs (McCook+, 2008)
J/MNRAS/411/2770 : Hot white dwarfs in GALEX-DR5 (Bianchi+, 2011)
J/AJ/135/1239 : Spectral distances to DA white dwarfs (Holberg+, 2008)
J/ApJS/167/40 : SDSS4 confirmed white dwarfs catalog (Eisenstein+, 2006)
J/AJ/132/1221 : VJHK and SDSS photometry of DA white dwarfs (Holberg+, 2006)
J/ApJS/119/207 : IUE echelle spectra of hot white dwarfs (Holberg+, 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [SDSS]
6- 24 A19 --- SDSS WD identification (JHHMMSS.ss+DDMMSS.s)
26- 33 F8.4 deg RAdeg Right ascension in decimal degrees (J2000)
35- 42 F8.4 deg DEdeg Declination in decimal degrees (J2000)
44- 48 F5.3 mag E(B-V) Reddening derived from the maps of Schlegel et
al. (1998ApJ...500..525S 1998ApJ...500..525S)
50- 53 F4.1 mag umag4 [16.4/17.9] SDSS-DR4 u-band magnitude
55 I1 --- N [1/4] Number of Swift epoch(s)
57- 59 I3 --- Ntot [36/134] Total number of UVOT images
61- 64 F4.1 ks Exp Exposure time
66- 70 I5 K Teff [22300/30800] Model effective temperature
72- 75 F4.2 [cm/s2] logg [7.25/7.95] Model gravity surface
77- 81 F5.3 mag Av [0.014/0.127] Model extinction (AV)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [SDSS]
6- 24 A19 --- SDSS SDSS identification (JHHMMSS.ss+DDMMSS.s)
26- 31 F6.3 mag FUV GALEX FUV AB magnitude (153±47nm)
33- 37 F5.3 mag e_FUV FUV uncertainty (1)
39- 44 F6.3 mag NUV GALEX NUV AB magnitude (231±62nm)
46- 50 F5.3 mag e_NUV NUV uncertainty (1)
52- 57 F6.3 mag uvw2 Swift/UVOT UVW2-band AB magnitude (193±65nm)
59- 63 F5.3 mag e_uvw2 uvw2 uncertainty (1)
65- 70 F6.3 mag uvm2 Swift/UVOT UVM2-band AB magnitude (225±50nm)
72- 76 F5.3 mag e_uvm2 uvm2 uncertainty (1)
78- 83 F6.3 mag uvw1 Swift/UVOT UVW1-band AB magnitude (260±69nm)
85- 89 F5.3 mag e_uvw1 uvw1 uncertainty (1)
91- 96 F6.3 mag umag Swift/UVOT U-band AB magnitude (347±79nm)
98-102 F5.3 mag e_umag umag uncertainty (1)
104-107 F4.2 --- Var [0.38/2.87] Variability index
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Note (1): Systematic uncertainties are ±0.05, 0.03, 0.03, 0.03, 0.03 and 0.02
for FUV, NUV, uvw2, uvm2, uvw1 and u-band, respectively.
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SDSS DA WD identification (JHHMMSS.ss+DDMMSS.s)
21- 27 F7.1 0.1nm lambda [1300/11300] Wavelength
29- 38 E10.4 cW/m2/nm Flux Model Flux in units of erg/s/cm2/Angstrom
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 08-Aug-2012