J/other/MmSAI/80.833 Variations of the fine-structure constant (Murphy+, 2009)
Keck constraints on a varying fine-structure constant:
wavelength calibration errors.
Murphy M.T., Webb J.K., Flambaum V.
<Mem. Soc. Astron. Ital., 80, 833-841 (2009)>
=2009MmSAI..80..833M 2009MmSAI..80..833M
ADC_Keywords: Atomic physics ; QSOs
Keywords: Instrumentation: spectrographs - Techniques: spectroscopic -
Cosmology: observations - Quasars: absorption lines - Line: profiles
Abstract:
The Keck telescope's High Resolution Spectrograph (HIRES) has
previously provided evidence for a smaller fine-structure constant,
α, compared to the current laboratory value, in a sample of 143
quasar absorption systems:
Δα/α=(-0.57±0.11)10-5. The analysis was based on
a variety of metal-ion transitions which, if alpha varies, experience
different relative velocity shifts. This result is yet to be robustly
contradicted, or confirmed, by measurements on other telescopes and
spectrographs; it remains crucial to do so.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 76 143 Values of Δ(α)/α and corrections
for possible intra-order distortions of the
wavelength scale
trans.dat 66 23 Transition codes, from Murphy et al.
(2003, Cat. J/MNRAS/345/609)
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See also:
J/MNRAS/345/609 : Variability of the fine-structure constant (Murphy+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name B1950 QSO name (HHMM-DDM)
12- 16 F5.3 --- zem ?=- Emission redshift
18- 24 F7.5 --- zabs Absorption redshift
26- 39 A14 --- Trans Transitions used to determine da/a in each
absorber (1)
43- 48 F6.3 --- da/a Δα/α value (relative
variation of the fine structure constant)
50- 54 F5.3 --- e_da/a Formal 1-sigma statistical error on da/a
56- 60 F5.3 --- d(da/a) Systematic error on da/a (2)
62- 67 F6.3 --- da/aC Estimate of the da/a correction, intra-order
distortions, to be added to da/a
69- 73 F5.3 --- d(da/aC) Systematic error term on da/acorr (3)
75- 76 A2 --- Sam Observational sub-samples employed (4)
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Note (1): Each letter represents a transition and the key is provided in
trans.dat file, from table 2 of Murphy et al. (2003, Cat. J/MNRAS/345/609)
Note (2): is non-zero only for "high-contrast" absorbers; see text for
explanation.
Note (3): which was calculated in the same way as delta(da/a)_sys but using
the corrected values of da/a.
Note (4): Sub-samples codes as follows:
A = "Previous low-z sample" from Murphy et al. (2003, J/MNRAS/345/609)
B1 = "Previous high-z sample" from Murphy et al. (2003, J/MNRAS/345/609)
B2 = The 15 absorbers added in Murphy et al. (2004, LNP, 648, 131)
C = "New sample" from Murphy et al. (2003, J/MNRAS/345/609)
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Byte-by-byte Description of file: trans.dat
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Bytes Format Units Label Explanations
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1 A1 --- Trans Transition code
3- 8 A6 --- Ion Ion
10- 19 F10.5 0.1nm lambda0 Laboratory wavelength
21- 41 A21 --- Ground Ground state
43- 66 A24 --- Upper Upper state
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History:
Copied at http://astronomy.swin.edu.au/~mmurphy/MurphyM_09a.dat
(End) Patricia Vannier [CDS] 25-Jan-2010