VII/241 The 2dF QSO Redshift Survey (Croom+ 2004)
The 2dF QSO Redshift Survey (2QZ)
Croom S.M., Smith R.J., Boyle B.J., Shanks T., Miller L., Outram P.J.,
Loaring N.S.
<Mon. Not. R. Astron. Soc. 349, 1397 (2004)>
=2004MNRAS.349.1397C 2004MNRAS.349.1397C
ADC_Keywords: Active gal. nuclei; QSOs; Redshifts; Spectroscopy;
Stars, white dwarf; Stars, normal; Galaxies, spectra
Keywords: catalogues - surveys - white dwarfs - galaxies: active -
quasars: general - galaxies: Seyfert
Abstract:
The final catalogue of the 2dF QSO Redshift Survey (2QZ) is based on
Anglo-Australian Telescope 2dF spectroscopic observations of 44576
colour-selected (ubJr) objects with 18.25<bJ< 20.85 selected from
automated plate measurement scans of UK Schmidt Telescope (UKST)
photographic plates. The 2QZ comprises 23338 quasi-stellar objects
(QSOs), 12292 galactic stars (including 2071 white dwarfs) and 4558
compact narrow emission-line galaxies. We obtained a reliable
spectroscopic identification for 86 per cent of objects observed with
2dF. We also report on the 6dF QSO Redshift Survey (6QZ), based on
UKST 6dF observations of 1564 brighter (16<bJ<18.25) sources selected
from the same photographic input catalogue. In total, we identified
322 QSOs spectroscopically in the 6QZ. The completed 2QZ is, by more
than a factor of 50, the largest homogeneous QSO catalogue ever
constructed at these faint limits (bJ<20.85) and high QSO surface
densities (35 QSOs/deg2). As such, it represents an important
resource in the study of the Universe at moderate-to-high redshifts.
Description:
Spectroscopic observations of the input catalogue were made with the
2dF instrument at the Anglo-Australian Telescope (AAT; the 2QZ sample)
and the 6dF instrument at the UKST (the 6QZ sample). 2dF spectroscopic
observations began in January 1997 and were completed in April 2002.
Six-degree Field observations were performed over the period 2001
March-2002 September.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
2qz.dat 354 49425 2QZ catalogue: includes North and South galactic
poles, and 6QZ with another 1657 lines.
ngp_rep.dat 144 926 Additional spectra when more than 2 spectra (NGP)
sgp_rep.dat 145 1047 Additional spectra when more than 2 spectra (SGP)
6qz_rep.dat 145 87 Additional spectra when more than 2 spectra (6QZ)
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See also:
http://www.2dfquasar.org/ : the 2QZ Home Page
II/268 : 2QZ Photometric Catalog (Croom et al., 2005)
VII/235 : Quasars and Active Galactic Nuclei (11th Ed.) (Veron+, 2003)
Byte-by-byte Description of file: 2qz.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2QZ Name of the source in 2QZ (JHHMMSS.S+DDMMSS)
18- 19 I2 h RAh Right ascension (J2000)
21- 22 I2 min RAm Right ascension (J2000)
24- 28 F5.2 s RAs Right ascension (J2000)
30 A1 --- DE- Declination sign (J2000)
31- 32 I2 deg DEd Declination (J2000)
34- 35 I2 arcmin DEm Declination (J2000)
37- 40 F4.1 arcsec DEs Declination (J2000)
42- 46 I5 --- intNo Internal catalog object number
48- 57 A10 --- intName Internal name of the object
59- 83 A25 --- Sector Name of the sector this object inhabits
85- 86 I2 h RA1950h Right Ascension B1950 (hours)
88- 89 I2 min RA1950m Right Ascension B1950 (minutes)
91- 95 F5.2 s RA1950s Right Ascension B1950 (seconds)
97 A1 --- DE1950- Declination B1950 (sign)
98- 99 I2 deg DE1950d Declination B1950 (degrees)
101-102 I2 arcmin DE1950m Declination B1950 (minutes)
104-107 F4.1 arcsec DE1950s Declination B1950 (seconds)
109-111 I3 --- Field UKST Survey field number
113-121 F9.2 pix Xpos APM scan X position (1pix=8um)
123-131 F9.2 pix Ypos APM scan Y position (1pix=8um)
133-143 F11.8 rad RArad Right ascension B1950 (radians)
145-155 F11.8 rad DErad Declination B1950 (radians)
160-165 F6.3 mag bJmag bJ magnitude
170-175 F6.3 mag u-bJ u-bJ colour index
179-185 F7.3 mag bJ-r bJ-r colour index (G1)
189 I1 --- Nsp Number of observations (1)
191-196 F6.4 --- z1 Redshift from first spectrum
198-199 I2 --- q_z1 Quality flag for first spectrum (G3)
201-209 A9 --- ID1 Identification for first spectrum (G4)
212-219 I8 "YYYYMMDD" Date1 ? Date of observation for first spectrum
221-224 I4 --- Field1 field and spectrograph for first spectrum (G2)
226-228 I3 --- Fiber1 2dF fiber number
231-236 F6.2 --- S/N1 Signal-to-noise ratio for first spectrum (G5)
238-243 F6.4 --- z2 ?=0 Redshift from second spectrum
245-246 I2 --- q_z2 Quality flag for second spectrum (G3)
248-256 A9 --- ID2 Identification for second spectrum (G4)
259-266 I8 "YYYYMMDD" Date2 ? Date of observation for second spectrum
268-271 I4 --- Field2 field and spectrograph for 2nd spectrum (G2)
273-275 I3 --- Fiber2 2dF fiber number
278-283 F6.2 --- S/N2 Signal-to-noise ratio for second spectrum (G5)
285-289 F5.3 --- zprev ?=0 Redshift if previously known (2)
291-294 I4 mJy F21cm ?=0 Flux at 1.4GHz from NVSS (3)
295-296 A2 --- --- [.0]
298-304 F7.4 10-16W/m2 FX ?=0 Flux at 0.1-2.4keV from RASS (4)
306-312 F7.5 mag E(B-V) Reddening E(B-V) from Schegel et al.,
1998ApJ...500..525S 1998ApJ...500..525S
314-333 A20 --- Com1 Specific Comment on observation 1
335-354 A20 --- Com2 Specific Comment on observation 2
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Note (1): The number of independent spectra taken.
The highest quality spectrum is always spectrum 1.
When there are more than 2 spectra, details of the additional
spectral are given in the files ngp_rep.dat, sgp_rep.dat and
6qz_rep.dat (North and South galactic poles, and 6QZ, respectively)
Note (2): The previously known redshift is taken from the
"Quasars and Active Galactic Nuclei (9th Ed.)", Veron-Cetty M.P.,
Veron P., 2000, ESO Scientific Report 19, Cat. VII/215
Note (3): 1.4GHz radio flux is taken from the NRAO VLA Sky Survey (NVSS),
Condon et al., 1998AJ....115.1693C 1998AJ....115.1693C, Cat. VIII/65
Note (4): The X-ray flux is taken from the ROSAT All Sky Survey,
Voges et al., 1999A&A...349..389V 1999A&A...349..389V, Cat. IX/10; Voges et al.,
2000IAUC.7432R...1V 2000IAUC.7432R...1V. Counts/s in the 0.1 to 2.4keV band were converted
to flux in 10-13erg/s/cm2 (or equivalently 10-13mW/m2) assuming
a photon index of -2 giving a conversion factor of 5.6x10-12.
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Byte-by-byte Description of file: ngp_rep.dat sgp_rep.dat 6qz_rep.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2QZ Name of the source in 2QZ (JHHMMSS.S+DDMMSS)
18- 19 I2 h RAh Right ascension (J2000)
21- 22 I2 min RAm Right ascension (J2000)
24- 28 F5.2 s RAs Right ascension (J2000)
30 A1 --- DE- Declination sign
31- 32 I2 deg DEd Declination (J2000)
34- 35 I2 arcmin DEm Declination (J2000)
37- 40 F4.1 arcsec DEs Declination (J2000)
42- 51 A10 --- intName Internal name of the object
53- 58 F6.3 mag bJmag bJ magnitude
61- 66 F6.3 mag u-bJ u-bJ colour index
68- 74 F7.3 mag bJ-r bJ-r colour index (G1)
76- 81 F6.4 --- z Redshift from first spectrum
83- 84 I2 --- q_z Quality flag for first spectrum (G3)
86- 94 A9 --- ID Identification for first spectrum (G4)
97-104 I8 "YYYYMMDD" Date ? Date of observation for first spectrum
106-109 I4 --- Field field and spectrograph for first spectrum (G2)
111-113 I3 --- Fiber 2dF fiber number
115-120 F6.2 --- S/N1 Signal-to-noise ratio for first spectrum (G5)
121 A1 --- --- [0]
124 I1 --- No [3,6] Observation number
126-145 A20 --- Com Comment on observation
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Gloval Notes:
Note (G1): In the case of an object having only an upper limit in the
r-band, the bJ-r colour is defined as (bJ-rlim)-10. All r-band
detections have bJ-r>-1.5 while this definition gives all upper
limits bJ-r←9.8.
Note (G2): The number is defined as
2dF field number x10 + 2dF spectrograph number
e.g. field number 218 and spectrograph 2 gives 2182.
(the spectrograph number is 1 or 2)
Note (G3): Both redshift and identification are given separate quality
flags (1 = high-quality, 2 = low-quality, 3 = unclassifiable).
The quality number is set as
identification quality x 10 + redshift quality
Note (G4): The spectra are classified in six main categories:
QSO = for a spectrum with broad emission lines
NELG = (narrow-emission line galaxy) for a spectrum with narrow
emission lines
gal = a galaxy spectrum with no emission lines
star = a Galactic star spectrum
cont = a high signal-to-noise (S/N>10) spectrum with no identifiable
emission of absorption features
?? = an unclassifiable spectrum
Sub-classes are contained within parentheses after the main classifications:
DA = a DA white dwarf
DB = a DB white dwarf
DO = a DO white dwarf
DZ = a DZ white dwarf
CV = a star with strong hydrogen Balmer emission lines
DAM = a DA white dwarf - M-dwarf binary
DBM = a DB white dwarf - M-dwarf binary
BAL = a broad absorption line QSO
For example QSO(BAL), star(DA), star(CV). If the identification
has a class 2 quality then there is a ? appended to the end of
the identification.
Note (G5): Signal-to-noise calculated in a 400-490nm band
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History:
From the 2QZ site at http://www.2dfquasar.org/
(End) Francois Ochsenbein [CDS] 01-Jun-2006