Access to Astronomical Catalogues

← Click to display the menu
J/A+A/494/799       Large Quasar Astrometric Catalogue (LQAC)   (Souchay+, 2009)

The construction of the Large Quasar Astrometric Catalogue (LQAC). Souchay J., Andrei A.H., Barache C., Bouquillon S., Gontier A-M., Lambert S.B., Le Poncin-Lafitte C., Taris F., Arias E.F., Suchet D., Baudin M. <Astron. Astrophys. 494, 799 (2009)> =2009A&A...494..799S
ADC_Keywords: QSOs ; Positional data ; Photometry, UVBGRI ; Photometry, infrared ; Radio lines Keywords: reference systems - astrometry - quasars: general - catalogs Abstract: The very large and increasing number of quasars reckoned from various sky surveys leads to a large quantity of data which brings various and inhomogeneous information in the fields of astrometry, photometry, radioastronomy and spectroscopy. In this paper, we describe our work that aims to make available a general compilation of the largest number of recorded quasars obtained from all the available catalogues, with their best position estimates, and providing physical information at both optical and radio wavelengths. Description: We construct a catalogue compilation designated Large Quasar Astrometric Catalogue (LQAC) giving equatorial coordinates, multiband photometry, radio fluxes, redshift, luminosity distances and absolute magnitudes. For that construction, we gather the 12 largest quasar catalogues (4 from radio interferometry programs, 8 from optical surveys), and we carry out systematic cross-identifications of the objects. Informations concerning u, b, v, g, r, i, z, J, K photometry as well as redshift and radio fluxes at 1.4GHz, 2.3GHz, 5.0GHz, 8.4GHz and 24GHz are given when available. A small proportion of remaining objects, not reckoned by the 12 catalogues and included in the Veron-Cetty & Veron quasar catalogues, are added in the compilation. The LQAC contains 113666 quasars. We use up-to-date cosmological parameters as well as recent models for galactic extinction and K-correction in order to evaluate the absolute magnitudes of the objects. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file lqac.dat 221 113666 Quasars LQAC refs.dat 224 795 Reference of Redshift LQAC
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) 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/248 : Quasars and Active Galactic Nuclei (12th Ed.) (Veron+ 2006) : VLA catalog Byte-by-byte Description of file: lqac.dat
Bytes Format Units Label Explanations
1- 15 F15.11 deg RAdeg Right Ascension J2000 (degrees) (1) 17- 31 F15.11 deg DEdeg Declination J2000 (degrees) (1) 33- 52 A20 ---- Ref [A-M-] Flags indicating presence of the quasar in one of the 13 catalogues from A to M (2) 54- 55 A2 ---- FS [*!x?- ] Flag characteristic of the cross-identification ambiguity of quasars involving HB and VV06 (3) 57- 61 F5.2 mag Umag ?=0.00 Photometric magnitude in Optical U band between 300 and 400nm (4) 63- 67 F5.2 mag Bmag ?=0.00 Photometric magnitude in Optical B band between 400 and 500nm 69- 73 F5.2 mag Vmag ?=0.00 Photometric magnitude in Optical V band between 500 and 600nm 75- 79 F5.2 mag Gmag ?=0.00 Photometric magnitude in Optical G band between 400 and 500nm 81- 85 F5.2 mag Rmag ?=0.00 Photometric magnitude in Optical R band between 600 and 750nm 87- 91 F5.2 mag Imag ?=0.00 Photometric magnitude in Optical I band between 750 and 1000nm 93- 97 F5.2 mag Zmag ?=0.00 Photometric magnitude in Optical I band between 750 and 1000nm 99-103 F5.2 mag Jmag ?=0.00 Photometric magnitude in Infrared between 1000 and 1500nm 105-109 F5.2 mag Kmag ?=0.00 Photometric magnitude in Infrared between 2000 and 3000nm 111-121 F11.8 Jy S1.4 ?=0. Radio flux between 750 and 1500MHz (20cm) 123-133 F11.8 Jy S2.0 ?=0. Radio flux between 1500 and 3000MHz (13cm) 135-145 F11.8 Jy S5.0 ?=0. Radio flux between 3 and 6GHz (6cm) 147-157 F11.8 Jy S8.4 ?=0. Radio flux between 6 and 12GHz (3.6cm) 159-169 F11.8 Jy S23 ?=0. Radio flux between 12 and 30GHz (1.2cm) 171-175 F5.3 --- z ?=0.000 Redshift 177-179 A3 --- r_z Redshift reference (5) 181-189 F9.3 Mpc Dist ?=0. The value of the bolometric distance 191-195 F5.2 mag E(B-V) ?=99.90 E(B-V) reddening value (6) 197-201 F5.2 mag Kcor.B ?=99.90 K-correction in band B (6) 203-207 F5.2 mag Kcor.K ?=99.90 K-correction in band I (6) 209-214 F6.2 mag BMAG ?=0.00 Absolute magnitude at B band 216-221 F6.2 mag IMAG ?=0.00 Absolute magnitude at I band
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 (let 36 microas). Note that no quasar, even those belonging to the ICRF, 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 = ICRF-Ext2 (Fey et al., Cat. J/AJ/127/3587, ICRF-EXT.2) B = VLBA (Beasley et al., Cat. J/ApJS/141/13, VCS1, Fomalont et al., Cat. J/AJ/126/2562, VCS2) C = VLA-015, VLA catalog minus 15 sources, (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 (Adelman-McCarthy et al., Cat. II/282) F = 2QZ (Croom et al., Cat. VII/241) G = FIRST (Becker et al., Cat. VIII/71) H = VLA+015, VLA catalog (Cat. J/ApJS/141/13, J/AJ/126/2562, J/AJ/129/1163, J/AJ/131/1872) I = HB (Hewitt & Burbidge, Cat. VII/158) J = 2MASS (Cutri et al., 2003, Cat. II/246) K = GSC2.3 (Lasker et al., Cat. I/305) L = USNO B1.0 (Monet et al., Cat. I/284) M = VV06 (Veron et al., 2006, Cat. VII/248) Note (3): Cross-identification ambiguity of quasars: * For 2arcsec < cross-identification A and H<5arcsec z1 > 0, z2 > 0, Δz < 0.1 FS = * z1 > 0, z2 > 0, Δz > 0.1 FS = ! z1 = 0 or/and z2 = 0 FS = ! * For 5arcsec < cross-identification A and H<30arcsec z1 > 0, z2 > 0, Δz < 0.1 FS = x z1 > 0, z2 > 0, Δz > 0.1 FS = ? z1 = 0 or/and z2 = 0 FS = ? * For 2arcsec < cross-identification A-L and VV06<5arcsec z1 > 0, z2 > 0, Δz < 0.1 FS = * z1 > 0, z2 > 0, Δz > 0.1 FS = ! z1 = 0 or/and z2 = 0 FS = ! * For 5arcsec < cross-identification A-L and VV06<10arcsec z1 > 0, z2 > 0, Δz < 0.1 FS = x z1 > 0, z2 > 0, Δz > 0.1 FS = ? z1 = 0 or/and z2 = 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 D to I if the value of z has been taken from one of the six basic catalogues of the compilation where this item is present. In the opposite, when the value of z has been taken in VV06, a number linked to the catalogue reference in VV06 is given, from 1 to 791. These numbers are release for the origin of each redshift value. We order our catalogue reference numbers by decreasing number of quasars. If redshift is not known the reference is -- Note (6): Only for these columns, zero value are real. Unknown value are fixed to 99.90.
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 3 A3 ---- Ref Redshift reference in VLQAC 8- 11 I4 ---- V+V ?=-- Redshift reference in Veron & Veron 2006 (Cat. VII/248) 16- 20 I5 ---- Nqso Number of QSOs with this reference in VLQAC 22- 40 A19 ---- BibCode The 19-digit bibcode 42-224 A183 ---- Reference Bibliography reference
Acknowledgements: Christophe Barache, christophe.barache(at)
(End) C. Barache, J. Souchay [SYRTE], Patricia Vannier [CDS] 01-Dec-2008
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service