J/A+A/537/A99 Large Quasar Astrometric Catalogue 2 (LQAC-2) (Souchay+, 2012)
The second release of the Large Quasar Astrometric Catalogue (LQAC-2).
Souchay J., Andrei A.H., Barache C., Bouquillon S., Suchet D., Taris F.,
Peralta R.
<Astron. Astrophys. 537, A99 (2012)>
=2012A&A...537A..99S 2012A&A...537A..99S
ADC_Keywords: QSOs ; Positional data ; Photometry, UVBGRI ;
Photometry, infrared ; Radio lines
Keywords: cosmological parameters - astrometry - quasars: general - catalogs
Description:
First of all we make a substantial review of the definitions and
properties of quasars and AGN (Active Galactic Nuclei), the
differenciation of these objects being unclear in the literature and
even for specialists. This will serve our purpose when deciding which
kinds of objects will be taken into account in our compilation. Then
we carry out the cross-identification between the 9 catalogues of
quasars chosen for their accuracy and their huge number of objects,
using a flag for each of them, and including all the available data
related to magnitudes (infrared and optical), radiofluxes and
redshifts. We also perform cross identification with external
catalogues 2MASS, B1.0 and GSC2.3 in order to complete photometric
data of the objects. Moreover we compute the absolute magnitude of
our extragalactic objects by taking into account the recent studies
concerning the galactic absorption. In addition substantial
improvements are brought with respect to the first release of the
LQAC (Souchay et al., 2009, Cat. J/A+A/494/799).
At first a LQAC name is given for each object based on its equatorial
coordinates with respect to the ICRS, following a procedure which
creates no ambiguity for identification. At second the equatorial
coordinates of the objects are recomputed more accurately according to
the algorithms used for the elaboration of the Large Quasar Reference
Frame (LQRF) (Andrei et al., 2009, Cat. I/313). At third we introduce
a morphological classification for the objects which enables in
particular to define clearly if the object is point-like or extended.
Our final catalogue, called LQAC-2, contains 187 504 quasars. This is
roughly larger than the 113 666 quasars recorded in the first version
of the LQAC (Souchay et al., 2009, Cat. J/A+A/494/799) and a little
more than the number of quasars recorded in the up-dated version of
the Veron Cetty and Veron (2010, Cat. VII/258) catalogue, which was
the densest compilation of quasars up to now. In addition to the
quantitative and qualitative improvements brought by our compilation,
we discuss the homogeneity of the data and carry out statistical
analysis concerning the spatial density and the distance to the
closest neighbour.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lqac2.dat 298 187504 Quasars LQAC-2
refs.dat 189 1397 Reference of Redshift LQAC-2
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See also:
J/AJ/127/3587 : VLBI ICRF. II (Fey+, 2004)
J/ApJS/141/13 : First VLBA calibrator survey: VCS1 catalog (Beasley+, 2002)
J/AJ/126/2562 : Second VLBA calibrator survey: VCS2 (Fomalont+, 2003)
J/AJ/129/1163 : Third VLBA calibrator survey: VCS3 (Petrov+, 2005)
J/AJ/131/1872 : Fourth VLBA calibrator survey: VCS4 (Petrov+, 2006)
J/AJ/136/580 : Sixth VLBA calibrator survey: VCS6 (Petrov+, 2008)
J/MNRAS/372/425 : 2dF-SDSS Luminous Red Galaxy Survey, 2SLAQ (Cannon+, 2006)
J/MNRAS/392/19 : The 2dF-SDSS QSO survey (Croom+, 2009)
VIII/60 : Interferometer phase calibration sources (Patnaik+ 1998)
II/282 : SDSS Photometric Catalog, Release 6 (Adelman-McCarthy+, 2007)
VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)
VIII/71 : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)
VII/158 : Revised and Updated Catalog of QSO (Hewitt+ 1993)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
http://www.aoc.nrao.edu/~gtaylor/csource.html : VLA catalog
J/A+A/494/799 : Large Quasar Astrometric Catalogue (LQAC) (Souchay+, 2009)
Byte-by-byte Description of file: lqac2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [LQAC_]
6- 16 A11 --- LQAC Name given for each object based on
its equatorial coordinates (DDD+0DD_NNN),
LQACDDD+0DDNNN
19- 31 F13.9 deg RAdeg Right Ascension in decimal degrees (J2000) (1)
34- 46 F13.9 deg DEdeg Declination in decimal degrees (J2000) (1)
51- 61 F11.7 deg RA2deg ? Right Ascension in decimal degrees (J2000)
given by LQRF-2
66- 76 F11.7 deg DE2deg ? Declination in decimal degrees (J2000)
given by LQRF-2
78- 90 A13 --- Ref [A-M-] Flags indicating the presence of the
quasar in one of the 13 catalogues
from A to M (2)
92 A1 --- FS [*!x?- ] Flag characteristic of the
cross-identification ambiguity of quasars
involving HB and VV06 (3)
95 I1 --- FB [0/1] Flag when a quasar has a bad position in
the original catalogue (1=bad)
97-101 F5.2 mag Umag ?=0 Photometric magnitude in Optical U band
between 300 and 400nm (4)
103-107 F5.2 mag Bmag ?=0 Photometric magnitude in Optical B band
between 400 and 500nm
109-113 F5.2 mag Vmag ?=0 Photometric magnitude in Optical V band
between 500 and 600nm
115-119 F5.2 mag Gmag ?=0 Photometric magnitude in Optical G band
between 400 and 500nm
121-125 F5.2 mag Rmag ?=0 Photometric magnitude in Optical R band
between 600 and 700nm
127-131 F5.2 mag Imag ?=0 Photometric magnitude in Optical I band
between 700 and 900nm
133-137 F5.2 mag Zmag ?=0 Photometric magnitude in Optical I band
between 800 and 1000nm
139-143 F5.2 mag Jmag ?=0 Photometric magnitude in Infrared
between 1000 and 1500nm
145-149 F5.2 mag Kmag ?=0 Photometric magnitude in Infrared
between 2000 and 3000nm
151-155 F5.2 Jy S1.4 ?=0 Radio flux between 750 and 1500MHz (20cm)
157-161 F5.2 Jy S2.0 ?=0 Radio flux between 1500 and 3000MHz (13cm)
163-167 F5.2 Jy S5.0 ?=0 Radio flux between 3 and 6GHz (6 cm)
170-173 F4.2 Jy S8.4 ?=0 Radio flux between 6 and 12GHz (3.6cm)
175-179 F5.2 Jy S23 ?=0 Radio flux between 12 and 30GHz (1.2cm)
184-188 F5.3 --- z ?=0 Redshift
190-193 A4 --- r_z Redshift reference (5)
200-208 F9.3 Mpc Dist ?=0 The value of the bolometric distance
211-217 F7.3 mag E(B-V) E(B-V) reddening value
221-226 F6.3 mag Kcor.B K-correction in band B
230-235 F6.3 mag Kcor.K K-correction in band I
238-244 F7.3 mag BMAG ?=0 Absolute magnitude in B band
247-253 F7.3 mag IMAG ?=0 Absolute magnitude in I band
255-258 F4.2 --- I1B [0/10[? SHARP (probing skewness) in band B
260-263 F4.2 --- I2B [0/10[? SROUND (probing roundness) in band B
265-268 F4.2 --- I3B [0/10[? GROUND (probing normalness) in band B
270-273 F4.2 --- I1R [0/10[? SHARP (probing skewness) in band R
275-278 F4.2 --- I2R [0/10[? SROUND (probing roundness) in band R
280-283 F4.2 --- I3R [0/10[? GROUND (probing normalness) in band R
285-288 F4.2 --- I1I [0/10[? SHARP (probing skewness) in band I
290-293 F4.2 --- I2I [0/10[? SROUND (probing roundness) in band I
295-298 F4.2 --- I3I [0/10[? GROUND (probing normalness) in band I
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Note (1): The RA, DE coordinates of the quasar in the ICRS. These two
coordinates are given in degree, with a precision of 1x10-8 (36uas).
Note that no quasar,even those belonging to the ICRF2, guarantees this
level of accuracy, this lack of accuracy justifies that several final
digits are zero value.
Note (2): Reference catalogues are flagged with:
A = ICRF2 (Ma et al., 2009, IERS, Technical Note No. 35;
Boboltz et al., 2010, Bull. of the Am. Astron. Soc. 42,512)
B = VLBI (VCS Petrov et al., Cat. J/AJ/136/580, version 2010c)
C = VLA (Cat. J/ApJS/141/13, J/AJ/126/2562, J/AJ/129/1163, J/AJ/131/1872)
D = JVAS (Patnaik et al., Cat. VIII/60)
E = SDSS DR8, http://www.sdss8.org
F = 2QZ (Croom et al., Cat. VII/241)
G = 2df-SDSS (2df-SDSS LRG and QSO survey (2009));
da Angela et al., 2008MNRAS.383..565D 2008MNRAS.383..565D;
LRG: Cannon et al., Cat. J/MNRAS/372/425;
QOS: Croom et al., Cat. J/MNRAS/392/19
H = FIRST (Becker et al., Cat. VIII/71)
I = Hewitt with corrected position (Hewitt and Burbridge, VII/158)
J = 2MASS (just to complete magnitude) (Cutri et al., Cat. II/246)
K = GSC2.3 (just to complete magnitude) (Lasker et al., Cat. I/305)
L = B1.0 (just to complete magnitude) (Monet et al., Cat. I/284)
M = VV10 - QSO SDSS DR1 to DR7 (Veron and Veron 2010, Cat. VII/258)
Note (3): Cross-identification ambiguity of quasars:
* For 2 arcsec < cross-identification A-L and VV10 < 5 arcsec
z_1 > 0, z_2 > 0, Δz < 0.1 FS = *
z_1 > 0, z_2 > 0, Δz > 0.1 FS = !
z_1 = 0 or/and z_2 = 0 FS = !
* For 5 arcsec < cross-identification A-L and VV10 < 10 arcsec
z_1 > 0, z_2 > 0, Δz < 0.1 FS = x
z_1 > 0, z_2 > 0, Δz > 0.1 FS = ?
z_1 = 0 or/and z_2 = 0 FS = ?
* if no cross-identification ambiguity FS = -
Note (4): For each bandwidth the photometric system in which these magnitudes
have been measured are not homogeneous, the priority being indicated
by the flag in decreasing order of the letter corresponding catalogue.
Note (5): The redshift reference of catalogue from which it has been taken
respectively. This reference is a letter chosen from A to I if the
value of z has been taken from one of the 5 basic catalogues of the
compilation where this item is present. In the opposite, when the
value of z has been taken in VV10, a number linked to the catalogue
reference in VV10 is given, from 1 to 1392. These numbers are release
for the origine of each redshift value. We order our catalogue
reference numbers by decreasing number of quasars.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 4 A4 ---- Ref Redshift reference in LQAC-2
6- 9 I4 ---- V+V ? Redshift reference in Veron & Veron 2010
(Cat. VII/258)
11- 16 I6 ---- Nqso Number of QSO with this reference in LQAC-2
18- 36 A19 ---- BibCode The 19-digit bibcode
38-189 A152 ---- Reference Bibliography reference
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Acknowledgements:
Christophe Barache, christophe.barache(at)obspm.fr
Jean Sourchay, jean.souchay(at)obspm.fr
Observatoire Paris/SYRTE/CNRS UMR8630/UPMC
(End) C. Barache, J. Souchay [Obs. Paris], Patricia Vannier [CDS] 05-Dec-2011