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Title: FIRST COSMOLOGICAL CONSTRAINTS ON THE PROTON-TO-ELECTRON MASS RATIO FROM OBSERVATIONS OF ROTATIONAL TRANSITIONS OF METHANOL

Journal Article · · Astrophysical Journal Letters
;  [1];
  1. School of Mathematics and Physics, University of Tasmania, Private Bag 37, Hobart, TAS 7001 (Australia)

We have used the Australia Telescope Compact Array to measure the absorption from the 2{sub 0} {yields} 3{sub -1} E 12.2 GHz transition of methanol toward the z = 0.89 lensing galaxy in the PKS B1830-211 gravitational lens system. Comparison of the velocity of the main absorption feature with the published absorption spectrum from the 1{sub 0} {yields} 2{sub -1} E transition of methanol shows that they differ by -0.6 {+-} 1.6 km s{sup -1}. We can use these observations to constrain the changes in the proton-to-electron mass ratio {mu} from z = 0.89 to the present to 0.8 {+-} 2.1 Multiplication-Sign 10{sup -7}. This result is consistent, and of similar precision to recent observations at z = 0.68 achieved through comparison of a variety of rotational and inversion transitions, and approximately a factor of two better than previous constraints obtained in this source. Future more sensitive observations that incorporate additional rotational methanol transitions offer the prospect of improving current results by a factor of 5-10.

OSTI ID:
22048023
Journal Information:
Astrophysical Journal Letters, Vol. 747, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English