J/ApJS/185/20 UV-bright quasars (Syphers+, 2009)
Ten more new sightlines for the study of intergalactic helium, and hundreds of
Far-Ultraviolet-Bright quasars, from the Sloan Digital Sky Survey, galaxy
evolution explorer, and Hubble Space Telescope.
Syphers D., Anderson S.F., Zheng W., Haggard D., Meiksin A.,
Schneider D.P., York D.G.
<Astrophys. J. Suppl. Ser., 185, 20-31 (2009)>
=2009ApJS..185...20S 2009ApJS..185...20S
ADC_Keywords: QSOs ; Photometry, ultraviolet ; Redshifts ; Surveys ;
Keywords: catalogs - galaxies: active - intergalactic medium -
quasars: general - surveys - ultraviolet: galaxies
Abstract:
Absorption along quasar sightlines remains among the most sensitive
direct measures of HeII reionization in much of the intergalactic
medium (IGM). Until recently, fewer than a half-dozen unobscured
quasar sightlines suitable for the HeII Gunn-Peterson test were
known; although these handful demonstrated great promise, the small
sample size limited confidence in cosmological inferences. We have
recently added nine more such clean HeII quasars, exploiting Sloan
Digital Sky Survey (SDSS) quasar samples, broadband ultraviolet (UV)
imaging from Galaxy Evolution Explorer (GALEX), and high-yield UV
spectroscopic confirmations from Hubble Space Telescope (HST). Here we
markedly expand this approach by cross-correlating SDSS DR7 and GALEX
GR4+5 to catalog 428 SDSS and 165 other quasars with z>2.78 having
likely (∼70%) GALEX detections, suggesting they are bright into the
far-UV. Reconnaissance HST Cycle 16 Supplemental prism data for 29 of
these new quasar-GALEX matches spectroscopically confirm 17 as indeed
far-UV bright. At least 10 of these confirmations have clean
sightlines all the way down to HeII Lyα, substantially expanding the
number of known clean HeII quasars, and reaffirming the order of
magnitude enhanced efficiency of our selection technique. Combined
confirmations from this and our past programs yield more than 20 HeII
quasars, quintupling the sample. These provide substantial progress
toward a sample of HeII quasar sightlines large enough, and spanning
a sufficient redshift range, to enable statistical IGM studies that
may avoid individual object peculiarity and sightline variance. Our
expanded catalog of hundreds of high-likelihood far-UV-bright QSOs
additionally will be useful for understanding the extreme-UV
properties of the quasars themselves.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 73 428 Catalog of candidate EUV-bright SDSS/GALEX quasars
table2.dat 62 165 Catalog of candidate EUV-bright (non-SDSS)
VCV/GALEX quasars
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
J/AJ/133/1780 : GALEX/SDSS quasar catalog (Trammell+, 2007)
J/ApJ/664/53 : UV photometry of GALEX QSO candidates (Atlee+, 2007)
J/ApJ/690/1181 : New HII quasar sightlines (Syphers+, 2009)
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]
5- 23 A19 --- SDSS SDSS DR7 name (JHHMMSS.ss+DDMMSS.s)
25- 34 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
36- 45 F10.6 deg DEdeg Declination in decimal degrees (J2000)
47- 50 F4.2 --- z SDSS pipeline redshift (photometric)
52- 56 F5.2 mag zmag ? SDSS z-band magnitude
58- 62 F5.2 10-19W/m2/nm NUV ? GALEX NUV flux (177-300nm)
64- 68 F5.2 10-19W/m2/nm FUV ? GALEX FUV flux (120-177nm)
70- 71 I2 --- Insp [0/10] Inspection flag (1)
73 I1 --- Obs [0/3] Prior observation flag (G2)
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Note (1): 4-bit integer flag. These individual flags are additive for a given
object (e.g., 6 denotes a BAL with an LLS or DLA). Flags as follows:
1 = very near neighbor in the SDSS image
2 = probable LLS or DLA in the SDSS spectrum
3 = very near neighbor in the SDSS image and probable LLS or DLA
in the SDSS spectrum
4 = BAL (broad absorption-line)
5 = BAL with very near neighbor in the SDSS image
6 = BAL with probable LLS or DLA in the SDSS spectrum
7 = BAL with probable LLS or DLA in the SDSS spectrum
and very near neighbor in the SDSS image
8 = possible BAL
9 = possible BAL with very near neighbor in the SDSS image
10 = possible BAL with probable LLS or DLA in the SDSS spectrum
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Veron-Cetty & Veron (VCV) name
(Cat. VII/258)
18- 25 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000)
27- 34 F8.4 deg DEdeg Declination in decimal degrees (J2000)
36- 40 F5.3 --- z VCV redshift (spectroscopic)
42 A1 --- f_Vmag Band of Vmag when not V (1)
43- 47 F5.2 mag Vmag VCV V-band magnitude
49- 53 F5.2 10-19W/m2/nm NUV ? GALEX NUV flux (177-300nm)
55- 60 F6.2 10-19W/m2/nm FUV ? GALEX FUV flux (120-177nm)
62 I1 --- Obs [0/3] Prior observation flag (G2)
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Note (1): V magnitude unless otherwise marked:
* = photographic;
R = red;
I = infrared;
O = photographic O-plate;
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Global notes:
Note (G2): Flags as follows:
0 = object has not been observed with HST;
1 = object has been observed with FUV (to near 304Å rest) spectroscopy
through HST cycle 16 supplemental;
2 = object has been observed less conclusively, i.e., NUV spectroscopy,
UV imaging, or pre-COSTAR observation;
3 = object is a target for HST cycle 17 observation.
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History:
From electronic version of the journal
Reference:
Syphers et al. Paper I. 2009ApJ...690.1181S 2009ApJ...690.1181S. Cat. J/ApJ/690/1181.
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 08-Mar-2010