Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-08-05
Astronomy and Astrophysics
Astrophysics
17 pages, 10 figures, 8 tables
Scientific paper
(Abridged) Radio-astronomical observations of molecular cores in lines of NH3 (J,K)=(1,1), CCS J_N=2_1-1_0, HC3N J=5-4, and N2H+ J=1-0 are used to measure the relative radial velocity offsets, Delta V, between the NH3 (1,1) and other molecular transitions. Robust statistical analysis is applied to the n=207 individual measurements in the Perseus molecular cloud (PC), the Pipe Nebula (PN), and the infrared dark clouds (IRDCs) to deduce the mean value of Delta V and its uncertainty. The measured values of Delta V from the PC, PN, and IRDCs show statistically significant positive velocity shifts between the line centers of NH3 and other molecules. The most accurate estimates are obtained from subsamples of the NH3/CCS pairs observed in the PC (n=21) and the PN (n=8), Delta V = 36+/-7_stat+/-13.5_sys} m/s and 53+/-11_stat+/-13.5_sys m/s, respectively, and from the n=36 NH3/N2H+ and n=27 NH3/HC3N pairs observed in the IRDCs, Delta V = 148+/-32_stat+/-13.6_sys m/s and 115+/-37_stat+/-31_sys m/s, respectively. Being interpreted in terms of the electron-to-proton mass ratio variation, this gives Delta mu/mu = (4-14)10^{-8}, which is an order of magnitude more sensitive than previous astronomical constraints on this quantity.
Kozlov MiKhail G.
Levshakov Sergei A.
Molaro Paolo P.
No associations
LandOfFree
On spatial variations of the electron-to-proton mass ratio in the Milky Way does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On spatial variations of the electron-to-proton mass ratio in the Milky Way, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On spatial variations of the electron-to-proton mass ratio in the Milky Way will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-549883