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 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:
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FileName Lrecl Records Explanations
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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 114 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
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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
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Bytes Format Units Label Explanations
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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 ?
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Note (1): Derived from Schlegel et al. (1998ApJ...500..525S 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 2002AJ....123..485S) for a list of the different targeting
algorithms and their corresponding bits.
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Byte-by-byte Description of file: table2.dat table4.dat
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Bytes Format Units Label Explanations
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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
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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'.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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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
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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
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Mar-2006