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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
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:
FileName Lrecl Records Explanations
ReadMe 80 . This file lqac2.dat 298 187504 Quasars LQAC-2 refs.dat 189 1397 Reference of Redshift LQAC-2
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) : VLA catalog J/A+A/494/799 : Large Quasar Astrometric Catalogue (LQAC) (Souchay+, 2009) Byte-by-byte Description of file: lqac2.dat
Bytes Format Units Label Explanations
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
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, 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; 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.
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
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
Acknowledgements: Christophe Barache, christophe.barache(at) Jean Sourchay, jean.souchay(at) Observatoire Paris/SYRTE/CNRS UMR8630/UPMC
(End) C. Barache, J. Souchay [Obs. Paris], Patricia Vannier [CDS] 05-Dec-2011
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

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