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J/AJ/130/1345      Optical-infrared colors of CORALS QSOs       (Ellison+, 2005)

The optical-infrared colors of CORALS QSOs: searching for dust reddening associated with high-redshift damped Lyα systems. Ellison S.L., Hall P.B., Lira P. <Astron. J., 130, 1345-1357 (2005)> =2005AJ....130.1345E
ADC_Keywords: QSOs ; Redshifts ; Interstellar medium ; Photometry ; Abundances Keywords: dust, extinction - galaxies: high-redshift - ISM: general - quasars: absorption lines Abstract: The presence of dust in quasar absorbers, such as damped Lyα (DLA) systems, may cause the background QSO to appear reddened. We investigate the extent of this potential reddening by comparing the optical-to-infrared colors of QSOs with and without intervening absorbers. Our QSO sample is based on the Complete Optical and Radio Absorption Line System (CORALS) survey of Ellison and coworkers. The CORALS data set consists of 66 radio-selected QSOs at zem≥2.2 with complete optical identifications. We have obtained near-simultaneous B- and K-band magnitudes for a subset of the CORALS sample and supplemented our observations with further measurements published in the literature. In total, we have B-K colors for 42 of the 66 QSOs, of which 14 have intervening DLA systems. To account for redshift-related color changes, the B-K colors are normalized using the Sloan Digital Sky Survey QSO composite. Description: Since flat-spectrum radio-loud QSOs (RLQs) are highly variable, it is important to obtain optical and IR data from near-simultaneous epochs. We achieved this by using the optical (SuSI2) and IR (SofI) imagers on the New Technology Telescope (NTT) at La Silla Observatory. Our data were obtained during two runs in 2003 October and 2004 March. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 64 66 CORALS QSO magnitudes table3.dat 54 42 Normalized colors and intervening absorber properties for CORALS QSOs with near-simultaneous B-K colors
See also: J/MNRAS/354/L31 : SDSS DR2 QSO and DLA properties (Murphy+, 2004) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 9 A9 --- QSO The QSO name 11- 15 F5.3 --- z Redshift from emission lines 17- 20 F4.1 mag Bjmag ? The UKST Bj magnitude 22- 26 F5.2 mag Bmag ? The B band magnitude 28- 31 F4.2 mag e_Bmag ? Error in Bmag 33- 37 F5.2 mag Vmag ? The V band magnitude 39- 42 F4.2 mag e_Vmag ? Error in Vmag 44- 48 F5.2 mag Ksmag ? The Ks band magnitude 50- 53 F4.2 mag e_Ksmag ? Error in Ksmag 55- 63 A9 --- Ref Photometry reference (1)
Note (1): Photometry reference: This work, or FWW00 = Francis, Whiting & Webster (2000PASA...17...56F).
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 9 A9 --- QSO QSO name 11- 15 F5.3 --- zem ? Redshift from emission lines 17- 21 F5.3 --- zabs ? Absorption redshift 23- 27 F5.2 [cm-2] N(HI) ? HI column density 30- 34 F5.2 mag B-K ? Normalized (B-K) color index 36- 39 F4.2 mag e_B-K ? Error in B-K 41 A1 --- l_[Zn/H] Upper limit flag on [Zn/H] 42- 46 F5.2 [Sun] [Zn/H] ? [Zn/H] abundance 48- 52 F5.2 [Sun] [Fe/H] ? [Fe/H] abundance 54 I1 --- Ref ? Abundance origin (1)
Note (1): Abundance references, defined as follows: 1 = Akerman et al. 2005A&A...440..499A 2 = Ellison & Lopez 2001A&A...380..117E
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 24-Feb-2006
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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