J/MNRAS/452/4153 SDSS DR12 QSOs [OIII] doublet (Albareti+, 2015)
Constraint on the time variation of the fine-structure constant with the
SDSS-III/BOSS DR12 quasar sample.
Albareti F.D., Comparat J., Gutierrez C.M., Prada F., Paris I.,
Schlegel D., Lopez-Corredoira M., Schneider D.P., Manchado A.,
Garcia-Hernandez D.A., Petitjean P., Ge J.
<Mon. Not. R. Astron. Soc., 452, 4153-4168 (2015)>
=2015MNRAS.452.4153A 2015MNRAS.452.4153A (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; QSOs ; Redshifts ; Spectroscopy
Keywords: line: profiles - surveys - quasars: emission lines -
cosmology: observations - large-scale structure of Universe
Abstract:
From the Sloan Digital Sky Survey (SDSS) Data Release 12, which covers
the full Baryonic Oscillation Spectroscopic Survey (BOSS) footprint,
we investigate the possible variation of the fine-structure constant
over cosmological time-scales. We analyse the largest quasar sample
considered so far in the literature, which contains 13175 spectra
(10363 from SDSS-III/BOSS DR12+2812 from SDSS-II DR7) with redshift
z<1. We apply the emission-line method on the [OIII] doublet
(λλ4960, 5008Å) and obtain
Δα/α=(0.9±1.8)x10-5 for the relative variation
of the fine-structure constant. We also investigate the possible
sources of systematics: misidentification of the lines, sky OH lines,
Hβ and broad line contamination, Gaussian and Voigt fitting
profiles, optimal wavelength range for the Gaussian fits, chosen
polynomial order for the continuum spectrum, signal-to-noise ratio and
good quality of the fits. The uncertainty of the measurement is
dominated by the sky subtraction. The results presented in this work,
being systematics limited, have sufficient statistics to constrain
robustly the variation of the fine-structure constant in redshift bins
(Δz∼0.06) over the last 7.9Gyr. In addition, we study the
[NeIII] doublet (λλ3869, 3968Å) present in 462 quasar
spectra and discuss the systematic effects on using these emission
lines to constrain the fine-structure constant variation. Better
constraints on Δα/α(<10-6) using the emission-line
method would be possible with high-resolution spectroscopy and large
galaxy/qso surveys.
Description:
All the spectra used in this investigation were downloaded from the
SDSS Database.
The wavelength coverage of the SDSS-III/BOSS spectrograph is
3600-10400Å and that of the SDSS-II spectrograph is 3800-9200Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 276 13175 Combined sample
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See also:
J/ApJ/773/14 : BOSS: quasar luminosity function (Ross+, 2013)
J/ApJ/778/98 : Cross-correlation of SDSS QSOs & BOSS galaxies (Shen+, 2013)
J/ApJS/199/3 : The quasars MMT-BOSS pilot survey (Ross+, 2012)
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)
J/MNRAS/418/1055 : BOSS morphology of galaxies (Masters+, 2011)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- SDSS SDSS-DR12 designation
HHMMSS.ss+DDMMSS.s (J2000)
20- 26 F7.3 deg RAdeg Right Ascension in decimal degrees (J2000)
28- 34 F7.3 deg DEdeg Declination in decimal degrees (J2000)
36- 53 A18 --- THING THING ID
55- 58 I4 --- Plate Spectroscopic plate number
60- 64 I5 d MJD Spectroscopic MJD (>55000 SDSS-III/BOSS
spectra, <55000 SDSS-II spectra)
66- 69 I4 -- Fiber Spectroscopic fibre number
71- 79 F9.7 --- zvi Redshift from visual inspection
81- 92 F12.9 --- zpipe ?=-1 Redshift from BOSS pipeline
94-107 F14.11 --- e_zpipe ?=-1 Error on BOSS pipeline redshift
109-123 F15.12 --- alpha δα/α from the Gaussian fits
125-135 F11.9 --- e_alpha Standard error for δα/α
from the Gaussian fits
137-147 F11.6 --- SNO1 S/N for the [OIII] 4960Å line
149-157 F9.4 --- SNO2 S/N for the [OIII] 5008Å line
159-169 F11.7 --- SNHb S/N for the Hβ 4861Å line
171-177 F7.2 --- O1fit Line centroid for the [OIII] 4960Å line
179-186 F8.2 --- O2fit Line centroid for the [OIII] 5008Å line
188-197 F10.7 --- e_O1fit Error on O1fit
199-209 F11.8 --- e_O2fit Error on O2fit
211-221 F11.7 --- O1Amp Gaussian amplitude at the centre for the
[OIII] 4960Å line (O1_FLUX)
223-234 F12.7 --- O2Amp Gaussian amplitude at the centre for the
[OIII] 5008Å line (O2_FLUX)
236-245 F10.7 --- O1Width Gaussian width for the [OIII] 4960Å line
247-254 F8.5 --- O2Width Gaussian width for the [OIII] 5008Å line
256-276 A21 --- FileName File name to download from the SDSS server
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 14-Mar-2016