J/AJ/125/1711 Broad Absorption Line Quasars from SDSS (Reichard+, 2003)
A catalog of Broad Absorption Line Quasars from the
Sloan Digital Sky Survey Early Data Release.
Reichard T.A., Richards G.T., Schneider D.P., Hall P.B., Tolea A.,
Krolik J.H., Tsvetanov Z., Vanden Berk D.E., York D.G., Knapp G.R.,
Gunn J.E., Brinkmann J.
<Astron. J. 125, 1711 (2003)>
=2003AJ....125.1711R 2003AJ....125.1711R
ADC_Keywords: QSOs ; Redshifts ; Photometry, SDSS
Keywords: quasars: absorption lines - quasars: general
Abstract:
We present a catalog of 224 broad absorption line quasars (BALQSOs)
from the Sloan Digital Sky Survey's Early Data Release Quasar Catalog,
(Schneider et al., 2002, Cat. J/AJ/123/567) including a relatively
complete and homogeneous subsample of 131 BALQSOs. Since the
identification of BALQSOs is subject to considerable systematic
uncertainties, we attempt to create a complete sample of SDSS BALQSOs
by combining the results of two automated selection algorithms and a
by-eye classification scheme. One of these automated algorithms finds
broad absorption line troughs by comparing with a composite quasar
spectrum. We present the details of this algorithm and compare this
method with one that uses a power-law fit to the continuum. The
BALQSOs in our sample are further classified as high-ionization
BALQSOs (HiBALs), low-ionization BALQSOs (LoBALs), and BALQSOs with
excited iron absorption features (FeLoBALs); composite spectra of each
type are presented. We further present a study of the properties of
the BALQSOs in terms of the balnicity distribution, which rises with
decreasing balnicity. This distribution of balnicities suggests that
the fraction of quasars with intrinsic outflows may be significantly
underestimated.
The balnicity index defined by Weymann et al. (1991ApJ...373...23W 1991ApJ...373...23W)
amounts to a sort of equivalent width: a quasar is declared to be a
BAL when its balnicity index is ≥0.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 100 185 SDSS EDR BALQSO Catalog: Objects with 1.7≤z≤4.2
table2.dat 99 39 Supplementary SDSS EDR BALQSO Catalog
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See also:
J/AJ/123/567 : SDSS quasar catalog (Schneider+, 2002)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSS SDSS object name (1)
20- 22 I3 --- PNum Plate number
24- 26 I3 --- FNum Fiber number
28- 32 I5 d MJD Modified Julian Date of observation
34 I1 --- Final [0/1] Final quasar target candidate (2)
36 I1 --- EDR [0/1] Early Data Release quasar target
candidate (2)
38 I1 --- Ser [0/1] Early Data Release serendipity target
candidate (2)
40- 44 F5.2 mJy 20cm ? FIRST peak flux density at 20cm (3)
46- 50 F5.3 --- z Redshift
52- 56 F5.2 mag i*mag Apparent i*-band magnitude (4)
58- 63 F6.2 mag i*Mag Resulting absolute i*-band magnitude
65- 69 I5 km/s CIV1 ? C IV balnicity index (5)
71- 75 I5 km/s CIV2 ? C IV balnicity index from Tolea et al.,
2002ApJ...578L..31T 2002ApJ...578L..31T (6)
77- 80 I4 km/s MgII ? Mg II balnicity index (5)
82 A1 --- C1 [HN] Fitted composite algorithm
classification (7)
84 A1 --- C2 [HN] The Tolea et al., 2002ApJ...578L..31T 2002ApJ...578L..31T
classification (7)
86- 91 A6 --- C3 Visual classification (8)
93- 96 A4 --- C4 Overall classification (9)
98- 99 A2 --- Notes Additional notes (10)
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Note (1): Using the SDSS format of J2000 right ascension (hhmmss.ss) and
declination (±ddmmss.s). The "J" prefix should be added.
Note (2): Final quasar target candidate:
1 = Selected;
0 = Not selected.
Note (3): Null value indicates that the object is undetected in the FIRST
survey at the ∼1mJy limit.
Note (4): Corrected for Galactic reddening using Schlegel, Finkbeiner,
& Davis, 1998ApJ...500..525S 1998ApJ...500..525S.
Note (5): Computed using a fitted EDR composite spectrum as the continuum.
Note (6): Computed using a power law with Gaussian C IV emission line as
the continuum.
Note (7): Classification:
H = HiBAL;
N = Non-BALQSO.
Note (8): A question mark means uncertainty in the previous code;
e.g., ``HiLo?'' means a tentative LoBAL through in a definite HiBAL.
HiZ = HiBAL at z≥3.90, where LoBALs could be missed because
λAlIII>9150Å;
Hiz/Loz = Hi/LoBAL at z≥2.26, where LoBALs could be missed because
λMgII>9150Å;
Hi = Only high-ionization lines are present;
Lo = Both high- and low-ionization lines are present;
LoZ = LoBAL at z≥3.90, where LoBALs could be missed because
λAlIII>9150Å;
FeLo = High-, low-, and metastable Fe II/Fe III lines (∼2600Å,
or otherwise) or atypical absorption that more readily
classifies the object as an unusual or extreme BALQSO,
usually with strong iron absorption;
no = No broad absorption lines are present (non-BAL).
Note (9): Overall classification:
Lo = LoBAL if visual inspection classified the object as a LoBAL;
FeLo = Visual inspection also revealed a few unusual LoBALs with
iron absorption (FeLoBALs);
Hi = The remaining objects are those classified as HiBALs by at
least one of the three classification methods.
Note (10): Additional notes:
e: The balnicity indexes of these objects are formally zero (or
unmeasured), but visual inspection suggests that the objects
belong in this table.
For SDSS 0149-0114 and SDSS 1132+0104 a small change in redshift
would yield a positive BI.
In the case of SDSS 1730+5850, Hall et al., 2002ApJS..141..267H 2002ApJS..141..267H
found a BI greater than 10,900.
f: See also Hall et al., 2002ApJS..141..267H 2002ApJS..141..267H;
g: See also Menou et al., 2001ApJ...561..645M 2001ApJ...561..645M;
h: This quasar was selected for spectroscopic follow-up as a star;
i: This quasar was selected for spectroscopic follow-up as a galaxy.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 13-May-2003