Methanol as a tracer of fundamental constants

Abstract

The methanol molecule CH3OH has a complex microwave spectrum with a large number of very strong lines. This spectrum includes purely rotational transitions as well as transitions with contributions of the internal degree of freedom associated with the hindered rotation of the OH group. The latter takes place due to the tunneling of hydrogen through the potential barriers between three equivalent potential minima. Such transitions are highly sensitive to changes in the electron-to-proton mass ratio, mu = m_e/m_p, and have different responses to mu-variations. The highest sensitivity is found for the mixed rotation-tunneling transitions at low frequencies. Observing methanol lines provides more stringent limits on the hypothetical variation of mu than ammonia observation with the same velocity resolution. We show that the best quality radio astronomical data on methanol maser lines constrain the variability of mu in the Milky Way at the level of |Delta mu/mu| < 28x10^{-9} (1sigma) which is in line with the previously obtained ammonia result, |Delta mu/mu| < 29x10^{-9} (1σ). This estimate can be further improved if the rest frequencies of the CH3OH microwave lines will be measured more accurately.

7 pages, 1 table, 1 figure. Accepted for publication in ApJ

References in corpus (9)

• Enhanced sensitivity to time-variation of m_p/m_e in the inversion spectrum of ammonia
• Class I methanol masers in the outflow of IRAS 16547-4247
• Constraining changes in the proton-electron mass ratio with inversion and rotational lines
• $\Lambda$-doublet spectra of diatomic radicals and their dependence on fundamental constants
• Discovery of the first methanol (CH3OH) maser in the Andromeda galaxy (M31)
• Methanol detection in M82
• Discovery of the new class I methanol maser transition at 23.4 GHz
• Sensitivity of the H3O+ inversion-rotational spectrum to changes in m_e/m_p
• Sensitivity of the isotopologues of hydronium to variation of the electron-to-proton mass ratio

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