J/AJ/121/2843 QSOs in 2MASS second incremental data release (Barkhouse+, 2001)
Quasars in the 2MASS second incremental data release. Barkhouse W.A., Hall P.B. <Astron. J. 121, 2843 (2001)> =2001AJ....121.2843B
ADC_Keywords: QSOs ; Radio sources ; Photometry, infrared Keywords: catalogs - galaxies: active - infrared: general - quasars: general Abstract: Using the 2MASS Second Incremental Data Release (Cat. <B/2mass>), we have searched for near-infrared counterparts to 13214 quasars from the Veron-Cetty & Veron (Cat. VII/215) catalog. We have detected counterparts within 4" for 2277 of the approximately 6320 quasars within the area covered by the 2MASS Second Incremental Data Release. Only 1.6% of these are expected to be chance coincidences. Though this sample is heterogeneous, we find that known radio-loud quasars are more likely to have large near-infrared-to-optical luminosity ratios than radio-quiet quasars are, at a statistically significant level. This is consistent with dust-reddened quasars being more common in radio-selected samples than in optically selected samples, due to stronger selection effects against dust-reddened quasars in the latter. We also find a statistically significant dearth of optically luminous quasars with large near-infrared-to-optical luminosity ratios. This can be explained in a dust obscuration model but not in a model where synchrotron emission extends from the radio into the near-infrared and creates such large ratios. We also find that selection of quasar candidates from the B-J/J-K color-color diagram, modeled on the V-J/J-K selection method of Warren, Hewett, & Foltz, is likely to be more sensitive to dust-obscured quasars than selection using only infrared-infrared colors. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 143 2277 VV00 Quasars Detected in 2MASS table2.dat 58 3999 VV00 Quasars With Only Upper Limits in 2MASS
See also: VII/215 : Quasars and Active Galactic Nuclei (9th Ed.) (Veron+ 2000) VII/224 : Quasars and Active Galactic Nuclei (10th Ed.) (Veron+ 2001) B/2mass : The 2MASS database (IPAC/UMass, 2000) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1 A1 --- f_2MASS [*] Indicates an object having two 2MASS counterparts within 4''. 2- 15 A14 --- 2MASS The 2MASS identification 17- 33 A17 --- VV00 Name entries of Veron-Cetty & Veron 2000 (1) 35- 44 F10.6 deg RAdeg Right Ascension in degrees (J2000) 46- 55 F10.6 deg DEdeg Declination in degrees (J2000) 57- 61 F5.2 [Jy] LNIR Log of the NIR luminosity 63- 67 F5.2 [Jy] Lopt Log of the Optical luminosity 69- 73 F5.2 mag bmag The bm band magnitude 75- 79 F5.2 mag rmag The rm band magnitude 81- 86 F6.3 mag Jmag The J band magnitude 88- 92 F5.3 mag e_Jmag Uncertainty in Jmag 94- 99 F6.3 mag Hmag The H band magnitude 101-105 F5.3 mag e_Hmag Uncertainty in Hmag 107-112 F6.3 mag Kmag The K band magnitude 114-118 F5.3 mag e_Kmag Uncertainty in Kmag 120-125 F6.2 mag BMag Absolute B band magnitude (2) 127-130 F4.2 arcsec Dis Distance to the associated optical source 132-137 F6.2 Jy Radio ?=-99.00 Flux density at 6 cm (3) 139-143 F5.3 --- z Redshift (2)
Note (1): Objects which have blank Name entries in Veron-Cetty & Veron (2000, Cat. VII/215) are identified here by the prefix VV followed by their coordinates in Veron-Cetty & Veron (2000, Cat. VII/215). Note (2): Data from Veron-Cetty & Veron (2000, Cat. VII/215). Note (3): Data from Veron-Cetty & Veron (2000, Cat. VII/215). Unavailable data entries are given as -99.00.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 17 A17 --- VV00 Name entry of Veron-Cetty & Veron (2000) (1) 19- 28 F10.6 deg RAdeg Right Ascension in degrees (J2000) 30- 39 F10.6 deg DEdeg Declination in degrees (J2000) 41- 45 F5.2 [Jy] Lopt Log of the optical luminosity 47- 52 F6.2 Jy Radio ?=-99.00 Flux density measured at 6 cm (2) 54- 58 F5.3 --- z Redshift
Note (1): Objects which have blank Name entries in Veron-Cetty & Veron (2000, Cat. VII/215) are identified here by the prefix VV followed by their coordinates in Veron-Cetty & Veron (2000, Cat. VII/215). Note (2): Unavailable data entries are given as -99.00.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 30-Aug-2001
|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|