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J/MNRAS/450/3904     Quasars narrow absorption lines from SDSS     (Chen+, 2015)

Narrow absorption lines with two observations from the Sloan Digital Sky Survey. Chen Z.-F., Gu Q.-S., Chen Y.-M., Cao Y. <Mon. Not. R. Astron. Soc., 450, 3904-3919 (2015)> =2015MNRAS.450.3904C (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Photometry, SDSS ; Redshifts ; Equivalent widths Keywords: catalogues - surveys - quasars: absorption lines - quasars: general Abstract: We assemble 3524 quasars from the Sloan Digital Sky Survey (SDSS) with repeated observations to search for variations of the narrow C IV λλ1548, 1551 and Mg II λλ2796, 2803 absorption doublets in spectral regions shortward of 7000Å in the observed frame, which corresponds to time-scales of about 150-2643d in the quasar rest frame. In these quasar spectra, we detect 3580 CIV absorption systems with zabs=1.5188-3.5212 and 1809 MgII absorption systems with zabs=0.3948-1.7167. In term of the absorber velocity (β) distribution in the quasar rest frame, we find a substantial number of CIV absorbers with β<0.06, which might be connected to absorption of quasar outflows. The outflow absorption peaks at υ∼2000km/s and drops rapidly below this peak value. Among 3580 CIV absorption systems, 52 systems (∼1.5 percent) show obvious variations in equivalent widths in the absorber rest frame (Wr): 16 enhanced, 16 emerged, 12 weakened and 8 disappeared systems, respectively. We find that changes in Wrλ1548 are related neither to the time-scales of the two SDSS observations nor to absorber velocities in the quasar rest frame. Variable absorption in low-ionization species is important to constrain the physical conditions of the absorbing gas. There are two variable MgII absorption systems measured from SDSS spectra detected by Hacker et al. (2013, J/MNRAS/434/163). However, in our MgII absorption sample, we find that neither shows variable absorption with confident levels of >4σ for λ2796 lines and >3σ for λ2803 lines. Description: The Baryon Oscillation Spectroscopic Survey (BOSS: Eisenstein et al. 2011AJ....142...72E; Paris et al. 2012, Cat. VII/269) is the main dark-time legacy survey of the third stage of the SDSS, which used the same 2.5-m telescope (Gunn et al. 2006AJ....131.2332G; Ross et al. 2012, J/ApJS/199/3) as the first and second stages of the SDSS (hereafter SDSS-I/II). SDSS-I/II spectra have a wavelength coverage from 3800-9200Å with a spectral resolution of 1800-2200 (e.g. York et al. 2000AJ....120.1579Y). BOSS spectra span a range from 3600-10500Å at a resolution of 1300-2500 (Paris et al. 2012, Cat. VII/269). During the first two years, BOSS detected 87822 quasars over an area of 3275 deg2, including 7932 quasars that were observed by SDSS-I/II as well. Quasars observed by both SDSS-I/II and BOSS provide a remarkable chance to study the variabilities of absorption lines in a large population. Throughout this work, we take the quasar emission redshifts provided by Hewett & Wild (2010, J/MNRAS/405/2302, http://das.sdss.org/va/Hewett_Wild_dr7qso_newz/) directly. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea1.dat 104 3580 Catalog of C IV λλ1548, 1551 Absorption Systems tablea2.dat 104 1808 Catalog of Mg II λλ2796, 2803 Absorption Systems
See also: VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012) VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017) J/ApJ/613/129 : Equivalent widths of QSOs (Wise+, 2004) J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010) J/ApJS/199/3 : The quasars MMT-BOSS pilot survey (Ross+, 2012) J/MNRAS/434/163 : QSOs narrow absorption line variability (Hacker+, 2013) J/ApJS/210/7 : BOSS narrow CIV absorption lines. I. zem≤2.4 (Chen+, 2014) J/ApJS/215/12 : BOSS narrow CIV absorption lines. II. zem>2.4 (Chen+, 2014) Byte-by-byte Description of file: tablea1.dat
Bytes Format Units Label Explanations
1- 18 A18 --- SDSS SDSS identifier (HHMMSS.ss+DDMMSS.s) 20- 25 F6.4 --- zem Redshift derived from emission lines 27- 32 F6.4 --- zabs Redshift derived from absorption lines 34- 37 I4 --- Plate-S SDSS-I/II plate identifier 39- 43 I5 d MJD-S Modified Julian Date of the observation 45- 48 I4 --- Fiber-S SDSS-I/II fiber identifier 50- 53 F4.2 0.1nm EW1548-S SDSS-I/II Rest equivalent width of C IV 1548Å (G1) 55- 58 F4.2 0.1nm e_EW1548-S SDSS-I/II EW1548-S divided by its 1σ error 60- 63 F4.2 0.1nm EW1551-S SDSS-I/II Rest equivalent width of C IV 1551Å (G1) 65- 68 F4.2 0.1nm e_EW1551-S SDSS-I/II EW1551-S divided by its 1σ error 70- 73 I4 --- Plate-B BOSS plate identifier 75- 79 I5 d MJD-B Modified Julian Date of the observation 81- 84 I4 --- Fiber-B BOSS fiber identifier 86- 89 F4.2 0.1nm EW1548-B BOSS Rest equivalent width of C IV 1548Å (G1) 91- 94 F4.2 0.1nm e_EW1548-B BOSS EW1548-B divided by its 1σ error 96- 99 F4.2 0.1nm EW1551-B BOSS Rest equivalent width of C IV 1551Å (G1) 101-104 F4.2 0.1nm e_EW1551-B BOSS EW1551-B divided by its 1σ error
Byte-by-byte Description of file: tablea2.dat
Bytes Format Units Label Explanations
1- 18 A18 --- SDSS SDSS identifier (HHMMSS.ss+DDMMSS.s) 20- 25 F6.4 --- zem Redshift derived from emission lines 27- 32 F6.4 --- zabs Redshift derived from absorption lines 34- 37 I4 --- Plate-S SDSS-I/II plate identifier 39- 43 I5 d MJD-S Modified Julian Date of the observation 45- 48 I4 --- Fiber-S SDSS-I/II fiber identifier 50- 53 F4.2 0.1nm EW2796-S SDSS-I/II Rest equivalent width of Mg II 2796Å (G1) 55- 58 F4.2 0.1nm e_EW2796-S SDSS-I/II EW2796-S divided by its 1σ error 60- 63 F4.2 0.1nm EW2803-S SDSS-I/II Rest equivalent width of Mg II 2803Å (G1) 65- 68 F4.2 0.1nm e_EW2803-S SDSS-I/II EW2803-S divided by its 1σ error 70- 73 I4 --- Plate-B SDSS-III plate identifier 75- 79 I5 d MJD-B Modified Julian Date of the observation 81- 84 I4 --- Fiber-B BOSS fiber identifier 86- 89 F4.2 0.1nm EW2796-B BOSS Rest equivalent width of Mg II 2796Å (G1) 91- 94 F4.2 0.1nm e_EW2796-B BOSS EW2796-B divided by its 1σ error 96- 99 F4.2 0.1nm EW2803-B BOSS Rest equivalent width of Mg II 2803Å (G1) 101-104 F4.2 0.1nm e_EW2803-B BOSS EW2803-B divided by its 1σ error
Global notes: Note (G1): In units of Angstroms.
History: From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 13-Dec-2017
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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