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J/AJ/129/2542       BL Lac from SDSS                         (Collinge+, 2005)

Optically identified BL Lacertae objects from the Sloan Digital Sky Survey. Collinge M.J., Strauss M.A., Hall P.B., Ivezic Z., Munn J.A., Schlegel D.J., Zakamska N.L., Anderson S.F., Harris H.C., Richards G.T., Schneider D.P., Voges W., York D.G., Margon B., Brinkmann J. <Astron. J., 129, 2542-2561 (2005)> =2005AJ....129.2542C
ADC_Keywords: BL Lac objects ; Photometry, SDSS ; Redshifts ; Proper motions ; Radio lines Keywords: BL Lacertae objects: general - galaxies: active - quasars: general Abstract: We present a sample of 386 BL Lacertae candidates identified from 2860deg2 of the Sloan Digital Sky Survey (SDSS) spectroscopic database. The candidates are primarily selected to have quasi-featureless optical spectra and low proper motions as measured from SDSS and USNO-B positions; however, our ability to separate Galactic from extragalactic quasi-featureless objects (QFOs) on the basis of proper motion alone is limited by the lack of reliable proper motion measurements for faint objects. Based largely on this remarkably clean color separation, we subdivide the sample into 240 probable candidates and 146 additional less probable (likely stellar) candidates. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 117 10 SDSS photometric and spectroscopic measurements, proper motions, and previous identifications for "probable" BL Lac candidates table2.dat 110 10 Multiwavelength data for "probable" BL Lac candidates table3.dat 117 10 SDSS photometric measurements and proper motions for "possible" BL Lac candidates table4.dat 110 10 Multiwavelength limits for "possible" BL Lac candidates table5.dat 69 27 Potential radio-weak BL Lac candidates
See also: III/241 : Spectroscopy of SDSS Data Release 3 (SDSS-DR3) (ARC, 2005) http://www.sdss.org/ : SDSS Home Page Byte-by-byte Description of file: table1.dat table3.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS designation (JHHMMSS.ss+DDMMSS.s) 25 A1 --- n_SDSS [*] *: SDSS data using DR2 reductions were not available for the object (G1) 27- 31 F5.2 mag umag SDSS u magnitude 33- 36 F4.2 mag e_umag rms uncertainty on umag 38- 42 F5.2 mag gmag SDSS g magnitude 44- 47 F4.2 mag e_gmag rms uncertainty on gmag 49- 53 F5.2 mag rmag SDSS r magnitude 55- 58 F4.2 mag e_rmag rms uncertainty on rmag 60- 64 F5.2 mag imag SDSS i magnitude 66- 69 F4.2 mag e_imag rms uncertainty on imag 71- 75 F5.2 mag zmag SDSS z magnitude 77- 80 F4.2 mag e_zmag rms uncertainty on zmag 82- 85 F4.2 mag Ar Absorption in rband (1) 87 A1 --- Morph [pr] Optical morphology (G2) 89- 97 I9 --- Target Target code (2) 99-100 A2 --- l_z [≥ ] Limit flag on z 101-106 F6.4 --- z ? Redshift 107 A1 --- u_z [?] Uncertainty flag on z 109-113 F5.1 mas/yr pm ? Proper motion 114 A1 --- u_pm [?] Uncertainty flag on pm 117 A1 --- Ident [Y/N] Previously reported in NED as a BL Lac object ?
Note (1): Derived from Schlegel et al. (1998ApJ...500..525S). Note (2): SDSS primary spectroscopic target code, in which each (binary) bit represents a flag for a different targeting algorithm; see Stoughton et al. (2002AJ....123..485S) for a list of the different targeting algorithms and their corresponding bits.
Byte-by-byte Description of file: table2.dat table4.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS designation (JHHMMSS.ss+DDMMSS.s) 26- 29 F4.2 10+20cm-2 NH Hydrogen column density 31 A1 --- Xray [BFU] X-ray match (1) 33- 36 F4.1 arcsec Sep1 ? RASS Separation 39 A1 --- l_CR Limit flag on CR 40- 43 F4.2 ct/s CR RASS Count rate 45- 48 F4.2 ct/s e_CR ? rms uncertainty on CR 50- 54 F5.1 s Exp RASS Exposition time 56 A1 --- l_F1keV Limit flag on F1keV 57- 60 F4.1 10-16W/m2/keV F1keV Energy flux at 1keV 62 A1 --- l_FX Limit flag on FX 63- 66 F4.1 10-16W/m2 FX RASS X-ray flux 68- 71 F4.2 arcsec Sep2 ? FIRST separation 73 A1 --- l_F1.4GHz Limit flag on F1.4GHz 74- 78 F5.1 mJy F1.4GHz ? FIRST flux at 1.4GHz 80- 83 F4.2 mJy rms ? FIRST rms level appropriate to the object's coordinates 85- 87 F3.1 arcsec Sep3 ? NVSS separation 89- 93 F5.1 mJy F1.4GHz2 ? NVSS flux at 1.4GHz 95- 98 F4.1 mJy e_F1.4GHz2 ? rms uncertainty on F1.4GHz2 100 A1 --- l_alphaOX Limit flag on alphaOX 101-104 F4.2 --- alphaOX Spectral index between optical and X-ray 106 A1 --- l_alphaRO Limit flag on alphaRO 107-110 F4.2 --- alphaRO ? Spectral index between radio and optical
Note (1): Match as follows: B = match in the RASS bright source catalog F = match in the RASS faint source catalog U = object was undetected, i.e. here was no match in either the BSC or the FSC within 1'.
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS designation (JHHMMSS.ss+DDMMSS.s) 25 A1 --- n_SDSS [*] *: SDSS data using DR2 reductions were not available for the object (G1) 27 A1 --- Morph [pr] Optical morphology (G2) 29- 30 A2 --- l_z [≥ ] Limit flag on z 31- 36 F6.4 --- z ? Redshift 37 A1 --- u_z [?] Uncertainty flag on z 39- 43 F5.1 mas/yr pm ? Proper motion 44 A1 --- u_pm [?] Uncertainty flag on pm 46 A1 --- l_alphaOX Limit flag on alphaOX 47- 51 F5.2 --- alphaOX Spectral index between optical and X-ray 53 A1 --- l_alphaRO Limit flag on alphaRO 54- 57 F4.2 --- alphaRO ? Spectral index between radio and optical 59 A1 --- l_logL5GHz Limit flag on logL5GHz 60- 63 F4.1 [10-7W/Hz] logL5GHz ? Luminosity at 5GHz
Global notes: Note (G1): The data reported are from the DR1 reductions. Note (G2): Optical morphology as follows: p = point-like in the SDSS image r = resolved
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Mar-2006
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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