| | |
| | |
Stat |
Members: 3645 Articles: 2'506'133 Articles rated: 2609
26 April 2024 |
|
| | | |
|
Article overview
| |
|
Improved constraints on possible variation of physical constants from H I 21cm and molecular QSO absorption lines | M. T. Murphy
; J. K. Webb
; V. V. Flambaum
; M. J. Drinkwater
; F. Combes
; T. Wiklind
; | Date: |
29 Dec 2000 | Journal: | Mon.Not.Roy.Astron.Soc. 327 (2001) 1244 | Subject: | astro-ph | Affiliation: | UNSW), J. K. Webb (UNSW), V. V. Flambaum (UNSW), M. J. Drinkwater (UMelb), F. Combes (Paris Obs.), T. Wiklind (OSO | Abstract: | QSO absorption spectra provide an extremely useful probe of possible cosmological variation in various physical constants. Comparison of H I 21cm absorption with corresponding molecular (rotational) absorption spectra allows us to constrain variation in y=alpha^2*g_p where alpha is the fine structure constant and g_p is the proton g-factor. We analyse spectra of two QSOs, PKS 1413+135 and TXS 0218+357, and derive values of dy/y at absorption redshifts of z=0.2467 and 0.6847 by simultaneous fitting of the H I 21cm and molecular lines. We find dy/y=(-0.20 +/- 0.44)*10^{-5} and dy/y=(-0.16 +/- 0.54)*10^{-5} respectively, indicating an insignificantly smaller y in the past. We compare our results with other recent constraints from the same two QSOs (Drinkwater et al. 1998; Carilli et al. 2000) and with our recent optical constraints which indicated a smaller alpha at higher redshifts. | Source: | arXiv, astro-ph/0101519 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |