Constraining the variation in the fine-structure constant using SDSS DR7 quasi-stellar object spectra
DSpace at IIT Bombay
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Title |
Constraining the variation in the fine-structure constant using SDSS DR7 quasi-stellar object spectra
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Creator |
RAHMANI, H
MAHESHWARI, N SRIANAND, R |
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Subject |
atomic data
line: profiles quasars: absorption lines quasars: emission lines TESTING FUNDAMENTAL PHYSICS SPACE-TIME VARIATION UVES LARGE PROGRAM COSMIC TIME SPECTROGRAPH VARIABILITY BOUNDS LIMITS ATOMS VARY |
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Description |
We report on a robust constraint on the possible variation of the fine-structure constant, alpha equivalent to e(2)/(h) over barc, obtained using O III lambda lambda 4959,5007 nebular emission lines from quasi-stellar objects (QSOs). We find Delta alpha/alpha = -(2.1 +/- 1.6) x 10(-5), based on a well-selected sample of 2347 QSOs from the Sloan Digital Sky Survey Data Release 7 with 0.02 < z < 0.74. Our result is consistent with a non-varying a at a level of 2 x 10(-5) over approximately 7 Gyr. This is the largest sample of extragalactic objects yet used to constrain the variation of alpha. While this constraint is not as stringent as those determined using the many-multiplet method, it is free from various systematic effects. A factor of similar to 4 improvement in Delta alpha/alpha achieved here compared to a previous study is consistent with what is expected based on the sample used here, which is a factor of 14 times larger. This suggests that errors are mainly dominated by statistical uncertainty. We also find that the ratio of transition probabilities corresponding to the O III lambda 5007 and lambda 4959 lines is 2.933 +/- 0.002, in good agreement with the measurements of the National Institute of Standards and Technology.
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Publisher |
OXFORD UNIV PRESS
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Date |
2014-12-28T11:42:28Z
2014-12-28T11:42:28Z 2014 |
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Type |
Article
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Identifier |
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 439(1)L70-L74
0035-8711 1365-2966 http://dx.doi.org/10.1093/mnrasl/slt183 http://dspace.library.iitb.ac.in/jspui/handle/100/16387 |
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Language |
English
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