J/AJ/130/734 Magnetic white dwarfs from SDSS DR2 and DR3 (Vanlandingham+, 2005)
Magnetic white dwarfs from the SDSS. II. The second and third data releases.
Vanlandingham K.M., Schmidt G.D., Eisenstein D.J., Harris H.C.,
Anderson S.F., Hall P.B., Liebert J., Schneider D.P., Silvestri N.M.,
Stinson G.S., Wolfe M.A.
<Astron. J., 130, 734-741 (2005)>
=2005AJ....130..734V 2005AJ....130..734V
ADC_Keywords: Stars, white dwarf ; Magnetic fields ; Photometry, SDSS
Keywords: stars: magnetic fields - white dwarfs
Abstract:
Fifty-two magnetic white dwarfs have been identified in spectroscopic
observations from the Sloan Digital Sky Survey (SDSS) obtained between
mid-2002 and the end of 2004, including Data Releases 2 and 3.
Although not as numerous or diverse as the discoveries from the first
data release, the collection exhibits polar field strengths ranging
from 1.5 to ∼1000MG and includes two new unusual atomic DQA examples,
a molecular DQ, and five stars that show hydrogen in fields above
500MG. The highest field example, SDSS J2346+3853, may be the most
strongly magnetic white dwarf yet discovered. Analysis of the
photometric data indicates that the magnetic sample spans the same
temperature range as for non-magnetic white dwarfs from the SDSS, and
support is found for previous claims that magnetic white dwarfs tend
to have larger masses than their non-magnetic counterparts. A glaring
exception to this trend is the apparently low-gravity object
SDSS J0933+1022, which may have a history involving a close binary
companion.
Description:
We use SDSS data (http://www.sdss.org).
Additional optical spectroscopy and spectropolarimetry were obtained
during the period 2004 February-December for several unusual and
questionable targets. These observations utilized the instrument SPOL
attached to the Steward Observatory 2.3m Bok Telescope on Kitt Peak
and the 6.5m MMT atop Mount Hopkins.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 108 52 New SDSS magnetic white dwarfs
table2.dat 56 52 Photometry of SDSS magnetic white dwarfs
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See also:
II/259 : The SDSS Photometric Catalog, Release 3 (Abazajian+ 2005)
http://www.sdss.org : SDSS Home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SDSS SDSS designation (JHHMMSS.ss+DDMMSS.s)
21- 24 I4 --- Plate SDSS Plate number
25 A1 --- --- [-]
26- 30 I5 --- MJD SDSS MJD number observation date
31 A1 --- --- [-]
32- 34 I3 --- Fiber SDSS Fiber number
36- 45 A10 "YYYY/MM/DD" Obs.date TAI observation date
47- 51 A5 "h:m" Obs.time TAI time of observation
53- 58 F6.1 hT Bp ?=- Magnetic field strength (in 106G)
59 A1 --- u_Bp [*] * when e_Bp>10%
61- 62 I2 deg i ?=- Inclination angle of the dipole axis,
63 A1 --- u_i [*] * when e_incl>10%
65-108 A44 --- Com Comments
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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- 19 A19 --- SDSS SDSS designation (JHHMMSS.ss+DDMMSS.s)
20 A1 --- n_SDSS [*] Individual note (1)
21- 25 F5.2 mag umag SDSS u magnitude
27- 31 F5.2 mag gmag SDSS g magnitude
33- 37 F5.2 mag rmag SDSS r magnitude
39- 43 F5.2 mag imag SDSS i magnitude
45- 49 F5.2 mag zmag SDSS z magnitude
51- 55 I5 K Teff ?=- Effective temperature (2)
56 A1 --- n_Teff [*] when e_Teff>1000K
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Note (1): J095442.91+091352.4 corrected into J095442.91+091354.4
(to fit to table1)
Note (2): Temperature based on ugriz fiber magnitudes of 17.40, 17.30,
17.60, 17.88, and 18.21, respectively.
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History:
From electronic version of the journal
References:
Schmidt et al., Paper I 2003ApJ...595.1101S 2003ApJ...595.1101S
(End) Patricia Vannier [CDS] 09-Oct-2008