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J/MNRAS/382/515   SDSS ultracool and halo WD candidates    (Vidrih+, 2007)

New ultracool and halo white dwarf candidates in SDSS Stripe 82. Vidrih S., Bramich D.M., Hewett P.C., Evans N.W., Gilmore G., Hodgkin S., Smith M., Wyrzykowski L., Belokurov V., Fellhauer M., Irwin M.J., Mcmahon R.G., Zucker D., Munn J.A., Lin H., Miknaitis G., Harris H.C., Lupton R.H., Schneider D.P. <Mon. Not. R. Astron. Soc., 382, 515-525 (2007)> =2007MNRAS.382..515V
ADC_Keywords: Stars, white dwarf ; Photometry, SDSS ; Proper motions Keywords: catalogues - stars: atmospheres - stars: evolution - white dwarfs Abstract: A 2.5x100°2 region along the celestial equator (Stripe 82) has been imaged repeatedly from 1998 to 2005 by the Sloan Digital Sky Survey (SDSS). A new catalogue of ∼4 million light-motion curves, together with over 200 derived statistical quantities, for objects in Stripe 82 brighter than r∼21.5 has been constructed by combining these data by Bramich et al. (2008MNRAS.386..887B). This catalogue is at present the deepest catalogue of its kind. Extracting ∼130000 objects with highest signal-to-noise ratio proper motions, we build a reduced proper motion diagram to illustrate the scientific promise of the catalogue. In this diagram, disc and halo subdwarfs are well-separated from the cool white dwarf sequence. Our sample of 1049 cool white dwarf candidates includes at least eight and possibly 21 new ultracool H-rich white dwarfs (Teff<4000K) and one new ultracool He-rich white dwarf candidate identified from their SDSS optical and UKIDSS infrared photometry. At least 10 new halo white dwarfs are also identified from their kinematics. Description: SDSS is an imaging and spectroscopic survey that has mapped more than a quarter of the sky. Imaging data are produced simultaneously in five photometric bands, namely u, g, r, i and z. The data are processed through pipelines to measure photometric and astrometric properties . SDSS Stripe 82 covers a ∼250deg2 area of sky, consisting of a 2.5° strip along the celestial equator from right ascension -49.5° to +49.5°. The stripe has been repeatedly imaged between June and December each year from 1998 to 2005. Sixty-two of the total of 134 available imaging runs were obtained in 2005. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 136 24 Properties of the ultracool white dwarf candidates table2.dat 136 34 Properties of the halo white dwarf candidates notes.dat 74 34 Notes
See also: II/282 : The SDSS Photometric Catalog, Release 6 (Adelman-McCarthy+, 2007) http://www.sdss.org : SDSS Home Page Byte-by-byte Description of file: table[12].dat
Bytes Format Units Label Explanations
1- 18 A18 --- SDSSJ Object SDSS J name (HHMMSS.ss+DDMMSS.s) 19 A1 --- f_SDSSJ [*] Not fully confirmed halo WD candidate (1) 20 A1 --- n_SDSSJ Note on SDSSJ, in notes.dat file 22- 26 F5.2 mag gmag SDSS g magnitude in AB system 28- 31 F4.2 mag e_gmag rms uncertainty on gmag 33- 37 F5.2 mag rmag SDSS r magnitude in AB system 39- 42 F4.2 mag e_rmag rms uncertainty on rmag 44- 48 F5.2 mag imag SDSS i magnitude in AB system 50- 53 F4.2 mag e_imag rms uncertainty on imag 55- 59 F5.2 mag zmag SDSS z magnitude in AB system 61- 64 F4.2 mag e_zmag rms uncertainty on zmag 66- 70 F5.2 mag Jmag ? J magnitude in AB system (2) 72- 75 F4.2 mag e_Jmag ? rms uncertainty on Jmag (2) 77 A1 --- l_Hmag Limit flag on Hmag 78- 82 F5.2 mag Hmag ? H magnitude in AB system (2) 83 A1 --- n_Hmag [c] 5σ detection limit 84- 87 F4.2 mag e_Hmag ? rms uncertainty on Hmag (2) 89 A1 --- l_Kmag Limit flag on Kmag 90- 94 F5.2 mag Kmag ? K magnitude in AB system (2) 95 A1 --- n_Kmag [c] 5σ detection limit 96- 99 F4.2 mag e_Kmag ? rms uncertainty on Kmag (2) 101-104 I4 mas/yr pm Total proper motion 106-107 I2 mas/yr e_pm rms uncertainty on pm 109-111 I3 deg pmPA Proper motion position angle 113-116 I4 pc Dist Heliocentric distance 118-120 I3 km/s Vt Tangential velocity 122-126 I5 K Teff Effective temperature 128-131 F4.1 ---- chi2 chi2 value 133-136 A4 --- Type [H/He ] H-rich and/or He-rich white dwarf
Note (1): * = Only the best and not also the second best solution predict a halo white dwarf candidate. Note (2): The UKIDSS Vega magnitudes are converted to the AB system adopting a magnitude for Vega of +0.03 and the pass-band zero-point offsets from Hewett et al. (2006MNRAS.367..454H).
Byte-by-byte Description of file: notes.dat
Bytes Format Units Label Explanations
1 A1 --- ID Note identification letter 3- 74 A72 --- Note Text of the note
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 10-Nov-2008
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

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