Abstract
The optical spectra of objects classified as QSOs in the SDSS DR6 are analyzed with the aim of determining the value of the fine structure constant in the past and then check for possible changes in the constant over cosmological timescales. The analysis is done by measuring the position of the fine structure lines of the [OIII] doublet (λλ4959 and λλ5008) in QSO nebular emission. From the sample of QSOs at redshifts z < 0. 8 a sub sample was selected on the basis of the amplitude and width of the [OIII] lines. Two different method were used to determine the position of the lines of the [OIII] doublet, both giving similar results. Using a clean sample containing 1568 of such spectra, a value of \(\Delta \alpha /\alpha = (+2.4 \pm 2.5) \times 1{0}^{-5}\) (in the range of redshifts z ∼ 0 − 0. 8) was determined. The use of a larger number of spectra allows a factor ∼ 5 improvement on previous constraints based on the same method. On the whole, we find no evidence of changes in α on such cosmological timescales. The mean variation compatible with our results is \(1/ < t >\Delta \alpha /\alpha = (+0.7 \pm 0.7) \times 1{0}^{-14}\) yr − 1.
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References
J.N. Bahcall and E.E. Salpeter, Astrophys. J. 142 (1965) 1677
J.N. Bahcall, W.L.W. Sargent and M. Schmidt, Astrophys. J, 149 (1967) 211
J.N. Bahcall, C.L. Steinhardt and D. Schlegel, Astrophys. J, 600 (2004) 520
H. Chand, et al., A&A 430 (2005) 47
E. García-Berro, J. Isern and Y.A. Kubyshin, A&AR, 14 (2007) 113
D. Grupe, A.K. Pradhan and S. Frank, AJ, 130 (2005) 355
K. Ichikawa and M. Kawasaki, Phys. Rev. D65 (2002) 123511
N. Kanekar et al., Mod. Phys. Lett. A23 (2008) 2711.
S.J. Landau and C. Simeone, 487 (2008) 857
S.A. Levshakov et al., A&A 434 (2005) 827
S.A. Levshakov et al., A&A, 466 (2007) 1077
P. Molaro et al., Eur. Phys. J. Special Topics 163 (2008) 173
M.T. Murphy, J.K. Webb and V.V. Flambaum, MNRAS 345 (2003) 609
M. Nakashima, R. Nagata and J. Yokoyama, P. Th. Ph. 120 (2008) 1207
J.-P. Uzan, Rev. Mod. Phys. 75 (2003) 403
J.K. Webb et al., Phys. Rev. Lett. 82 (1999) 884
Acknowledgements
We have used the following online databases: Sloan Digital Sky Survey (http://www.sdss.org/), the Atomic Line List (http://www.pa.uky.edu/~peter/atomic/), and NIST Atomic Spectra Database (http://physics.nist.gov/PhysRefData/ASD).
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Gutiérrez, C.M., López-Corredoira, M. (2011). The Value of the Fine Structure Constant Over Cosmological Times. In: Martins, C., Molaro, P. (eds) From Varying Couplings to Fundamental Physics. Astrophysics and Space Science Proceedings. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-19397-2_8
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DOI: https://doi.org/10.1007/978-3-642-19397-2_8
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