Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/82379

Download PDF (Accepted manuscript) (Adobe Acrobat PDF, -1 bytes)

Title

Keck telescope constraint on cosmological variation of the proton-to-electron mass ratio

Author(s)

Malec, A. L.;  Buning, R.;  Murphy, M. T.;  Milutinovic, N.;  Ellison, S. L.;  Prochaska, J. X.;  Kaper, L.;  Tumlinson, J.;  Carswell, R. F.;  Ubachs, W.

Abstract

Molecular transitions recently discovered at redshift zabs= 2.059 towards the bright background quasar J2123−0050 are analysed to limit cosmological variation in the proton-to-electron mass ratio, μ≡mp/me . Observed with the Keck telescope, the optical echelle spectrum has the highest resolving power and largest number (86) of H2 transitions in such analyses so far. Also, (seven) HD transitions are used for the first time to constrain μ-variation. These factors, and an analysis employing the fewest possible free parameters, strongly constrain μ's relative deviation from the current laboratory value: Δμ/μ= (+5.6 ± 5.5stat± 2.9sys) × 10−6 , indicating an insignificantly larger μ in the absorber. This is the first Keck result to complement recent null constraints from three systems at zabs > 2.5 observed with the Very Large Telescope. The main possible systematic errors stem from wavelength calibration uncertainties. In particular, distortions in the wavelength solution on echelle order scales are estimated to contribute approximately half the total systematic error component, but our estimate is model dependent and may therefore under or overestimate the real effect, if present. To assist future μ-variation analyses of this kind, and other astrophysical studies of H2 in general, we provide a compilation of the most precise laboratory wavelengths and calculated parameters important for absorption-line work with H2 transitions redwards of the hydrogen Lyman limit.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Monthly Notices of the Royal Astronomical Society, Vol. 403, no. 3 (Apr 2010), pp. 1541-1555

Publication year

2010

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

Absorption lines;  Atomic data;  Quasars;  Spectroscopic techniques

Publisher

Wiley-Blackwell Publishing

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1111/j.1365-2966.2009.16227.x

Copyright

Copyright © 2010 The Authors. Journal compilation copyright © 2010 Royal Astronomical Society. The accepted manuscript is reproduced in accordance with the copyright policy of the publisher. The definitive publication is available at www.interscience.wiley.com.

Research Projects

Galaxy formation and femtosecond frequency combs, Australian Research Council grant number DP0877998

Full text

Peer reviewed