J/AJ/126/2125 SDSS candidate type II quasars (Zakamska+, 2003)
Candidate type II quasars from the Sloan Digital Sky Survey.
I. Selection and optical properties of a sample at 0.3<z<0.83.
Zakamska N.L., Strauss M.A., Krolik J.H., Collinge M.J., Hall P.B., Hao L.,
Heckman T.M., Ivezic Z., Richards G.T., Schlegel D.J., Schneider D.P.,
Strateva I., Vanden Berk D.E., Anderson S.F., Brinkmann J.
<Astron. J., 126, 2125-2144 (2003)>
=2003AJ....126.2125Z 2003AJ....126.2125Z
ADC_Keywords: QSOs ; Photometry, SDSS ; Spectroscopy
Keywords: galaxies: active - quasars: emission lines - quasars: general -
surveys
Abstract:
Type II quasars are the long-sought luminous analogs of type 2 (narrow
emission line) Seyfert galaxies, suggested by unification models of
active galactic nuclei (AGNs) and postulated to account for an
appreciable fraction of the cosmic hard X-ray background. We present a
sample of 291 type II AGNs at redshifts 0.3<z<0.83 from the
spectroscopic data of the Sloan Digital Sky Survey. These objects have
narrow (FWHM<2000km/s), high equivalent width emission lines with
high-ionization line ratios. We describe the selection procedure and
discuss the optical properties of the sample. About 50% of the objects
have [O III] λ5008 line luminosities in the range
3x108-1010L☉, comparable to those of luminous (-27<MB←23)
quasars; this, along with other evidence, suggests that the objects in
the luminous subsample are type II quasars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 125 291 SDSS Type II AGNs at Redshifts 0.3<z<0.83
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See also:
J/AJ/123/567 : SDSS quasar catalog, I: Early Data Release (Schneider+, 2002)
J/AJ/126/2579 : SDSS quasar catalog. II. First data release (Schneider+, 2003)
J/AJ/128/1002 : SDSS candidate type II quasars. II (Zakamska+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [SDSS]
6- 24 A19 --- SDSS The SDSS name (1)
26 I1 --- DR1 [0/1] Availability in Data Release 1
(1 = Yes, 0 = No)
28- 32 F5.3 --- z Redshift based on [O II] (3728) emission line
34- 40 A7 --- TCode The seven-digit target code (2)
42- 46 F5.2 mag u*mag SDSS u*-band PSF magnitude
48- 51 F4.2 mag e_u*mag Error in u*mag
53- 57 F5.2 mag g*mag SDSS g*-band PSF magnitude
59- 62 F4.2 mag e_g*mag Error in g*mag
64- 68 F5.2 mag r*mag SDSS r*-band PSF magnitude
70- 73 F4.2 mag e_r*mag Error in r*mag
75- 79 F5.2 mag i*mag SDSS i*-band PSF magnitude
81- 84 F4.2 mag e_i*mag Error in i*mag
86- 90 F5.2 mag z*mag SDSS z*-band PSF magnitude
92- 95 F4.2 mag e_z*mag Error in z*mag
97- 99 I3 0.1nm EW[OII] Equivalent width of [O II] (3728)
101-104 I4 0.1nm EW[OIII] Equivalent width of [O III] (5008)
106-109 F4.2 [solLum] L[OII] Log of [O II] (3728) luminosity
111-115 F5.2 [solLum] L[OIII] Log of [O III] (5008) luminosity
117-123 F7.2 mJy Flux The FIRST 20cm flux (3)
125 I1 --- Com [0/1] Asymmetric lines (1 = Yes, 0 = No)
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Note (1): Coordinates are given in the Name as hhmmss.ss+ddmmss.s (J2000).
Note (2): The targeting information is in the 5+2 digit target code
that shows how the object was targeted for spectroscopy. The first
five digits indicate whether the object was targeted on one of the
main spectroscopic plates by the Galaxy, LRG, Quasar, High-redshift
quasar or Serendipity algorithms, in that order. A digit of 0 means
the object was not targeted by this method, while 1 means targeted.
The algorithms have different selection criteria and limiting
magnitudes, as described in section 2. The last two digits show
whether the object was targeted on one of the DSES or one of the
Special plates.
Note (3): Note on Flux:
0 = Not detected;
-1 = The field was not observed by FIRST.
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History:
From electronic version of the journal
References:
Zakamska et al., Paper II 2004AJ....128.1002Z 2004AJ....128.1002Z, Cat. J/AJ/128/1002
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 19-Dec-2003