J/AJ/127/899 Blue HB stars in SDSS (Sirko+, 2004)
Blue horizontal-branch stars in the Sloan Digital Sky Survey.
I. Sample selection and structure in the galactic halo.
Sirko E., Goodman J., Knapp G.R., Brinkmann J., Ivezic Z., Knerr E.J.,
Schlegel D., Schneider D.P., York D.G.
<Astron. J., 127, 899-913 (2004)>
=2004AJ....127..899S 2004AJ....127..899S
ADC_Keywords: Stars, blue ; Stars, horizontal branch ; Photometry, SDSS
Keywords: Galaxy: halo - Galaxy: structure - stars: horizontal-branch
Abstract:
We isolate samples of 733 bright (g<18) and 437 faint (g>18) high
Galactic latitude blue horizontal-branch stars with photometry and
spectroscopy in the Sloan Digital Sky Survey (SDSS). Comparison of
independent photometric and spectroscopic selection criteria indicates
that contamination from F and blue straggler stars is less than 10%
for bright stars (g<18) and about 25% for faint stars (g>18), and this
is qualitatively confirmed by proper motions based on the USNO-A
(I/252) catalog as first epoch. Analysis of repeated observations
shows that the errors in radial velocity are ∼26km/s. A relation
between absolute magnitude and color is established using the
horizontal branches of halo globular clusters observed by SDSS.
Bolometric corrections and colors are synthesized in the SDSS filters
from model spectra. The redder stars agree well in absolute magnitude
with accepted values for RR Lyrae stars. The resulting photometric
distances are accurate to about 0.2mag, with a median of about 25kpc.
Modest clumps in phase space exist and are consistent with the
previously reported tidal stream of the Sagittarius dwarf galaxy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 194 1170 List of 1170 BHB Stars Selected from SDSS
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See also:
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
J/AJ/123/567 : SDSS quasar catalog, I: Early Data Release (Schneider+, 2002)
J/AJ/126/2579 : SDSS quasar catalog. II. First data release (Schneider+, 2003)
J/AJ/125/1817 : SDSS Early-Type Galaxies Catalog (Bernardi+, 2003)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right ascension in decimal degrees (J2000)
11- 19 F9.5 deg DEdeg Declination in decimal degrees (J2000)
21- 29 F9.5 deg GLON Galactic longitude
31- 39 F9.5 deg GLAT Galactic latitude
41- 45 F5.2 mag umag Uncorrected SDSS u-band magnitude
47- 51 F5.2 mag gmag Uncorrected SDSS g-band magnitude
53- 57 F5.2 mag rmag Uncorrected SDSS r-band magnitude
59- 63 F5.2 mag imag Uncorrected SDSS i-band magnitude
65- 69 F5.2 mag zmag Uncorrected SDSS z-band magnitude
71- 75 F5.2 mag ucormag Extinction corrected SDSS u-band magnitude
77- 81 F5.2 mag gcormag Extinction corrected SDSS g-band magnitude
83- 87 F5.2 mag rcormag Extinction corrected SDSS r-band magnitude
89- 93 F5.2 mag icormag Extinction corrected SDSS i-band magnitude
95- 99 F5.2 mag zcormag Extinction corrected SDSS z-band magnitude
101-110 F10.7 --- z Heliocentric redshift
112-118 F7.2 km/s Vgal Galactocentric velocity (1)
120-125 F6.2 kpc Dist Distance (2)
127-133 F7.4 0.1nm D0.2-Hg Hγ width at 80% of continuum
135-140 F6.4 --- fm-Hg Hγ flux relative to the continuum at the
line minimum
142-148 F7.4 0.1nm D0.2-Hd Hδ width at 80% of continuum
150-155 F6.4 --- fm-Hd Hδ flux relative to the continuum at the
line minimum
157-162 F6.4 --- fm-CaII Ca II flux relative to the continuum at the
line minimum
164-170 F7.4 --- b-Hg Hγ Sersic profile "b" parameter
172-178 F7.4 --- c-Hg Hγ Sersic profile "c" parameter
180-186 F7.4 --- b-Hd Hδ Sersic profile "b" parameter
188-193 F6.4 --- c-Hd Hδ Sersic profile "c" parameter
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Note (1): Assuming V☉=(10,225,7)km/s.
Note (2): As determined by the method of section 7.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 02-Jul-2004