Related papers: Constraints on changes in the proton-electron mass…

Numerous accidental near-degeneracies exist between the $2\nu_2$ and $\nu_4$ rotation-vibration energy levels of ammonia. Transitions between these two states possess significantly enhanced sensitivity to a possible variation of the…

Molecular hydrogen (H2) absorption features observed in the line-of-sight to Q2348-011 at redshift zabs = 2.426 are analysed for the purpose of detecting a possible variation of the proton-to-electron mass ratio mu=mp/me. By its structure…

The Standard Model of particle physics assumes that the so-called fundamental constants are universal and unchanging. Absorption lines arising in molecular clouds along quasar sightlines offer a precise test for variations in the…

We have used the Karl G. Jansky Very Large Array (VLA) to search for 36 GHz and 44 GHz methanol (CH3OH) lines in a sample of 21 Galactic supernova remnants (SNRs). Mainly the regions of the SNRs with 1720 MHz OH masers were observed.…

We calculate the sensitivity of the inversion spectrum of ammonia to possible time-variation of the ratio of the proton mass to the electron mass, mu=m_p/m_e. For the inversion transition (lambda= 1.25 cm^{-1}) the relative frequency shift…

Methanol masers at 6.7 GHz have been found exclusively towards high-mass star forming regions. Recently, some Class 0 protostars have been found to display conditions similar to what are found in hot cores that are associated with massive…

We report on one of the highest sensitivity surveys for molecular lines in the frequency range 6.0 to 7.4 GHz conducted to date. The observations were done with the 305m Arecibo Telescope toward a sample of twelve intermediate/high-mass…

We present results from calculations of the physical conditions necessary for the occurrence of 36.169 ($4_{-1}-3_{0}\, E$), 44.070 ($7_{0}-6_{1}\,A^+$), 84.521 ($5_{-1}-4_{0}\,E$), and 95.169 ($8_{0}-7_{1}\,A^+$) GHz methanol (CH$_3$OH)…

We have used the Australia Telescope Compact Array (ATCA) to undertake the first high angular resolution observations of 37.7-GHz ($7_{-2} - 8_{-1}E$) methanol masers towards a sample of eleven high-mass star formation regions which host…

So far the only seemingly significant indication of a cosmological variation exists for the proton-to-electron mass ratio as stated by Reinhold et al. (2006). The measured indication of variation is based on the combined analysis of H2…

Absorption-line systems detected in high resolution quasar spectra can be used to compare the value of dimensionless fundamental constants such as the fine-structure constant, alpha, and the proton-to-electron mass ratio, mu = m_p/m_e, as…

Methanol (CH$_3$OH) is at the root of organic ice chemistry in protoplanetary disks. However, its weak emission has made detections difficult. To date, gas-phase CH$_3$OH has been detected in only one Class II disk, TW Hya. We use the…

We present results from the first molecular line survey to search for the fundamental complex organic molecule, methanol (CH$_{3}$OH), in 14 Class 0/I proto-brown dwarfs (proto-BDs). IRAM 30-m observations over the frequency range of 92-116…

The recent detection of gas-phase methanol (CH$_3$OH) lines in the disc of TW Hya by Walsh et al. provided the first observational constraints on the complex O-bearing organic content in protoplanetary discs. The emission has a ring-like…

We report a constraint on the cosmological variation of the proton g-factor, $g_p$. By comparing the measured redshifts between \mbox{H\,{\sc i}} 21 cm and OH 18 cm lines observed with the newly commissioned Five-hundred-meter Aperture…

We report the first observations in a rare family of class II methanol maser transitions in both CH$_3$OH and $^{13}$CH$_3$OH toward three southern high-mass star formation regions, along with the first maser detected in the $^{13}$CH$_3$OH…

We report the detection of the satellite 18 cm OH lines at 1612 and 1720 MHz in the z=0.2467 molecular absorption system toward the radio source PKS 1413+135. The two OH lines are conjugate; the 1612 MHz line is seen in absorption while the…

Transitions in atoms and molecules provide an ideal test ground for constraining or detecting a possible variation of the fundamental constants of nature. In this Perspective, we review molecular species that are of specific interest in the…

We report the discovery of 6.7 GHz methanol maser periodic flares in four massive star forming regions and the updated light curve for the known periodic source G22.357+0.066. The observations were carried out with the Torun 32 m radio…

The possible cosmological variation of the proton-to-electron mass ratio was estimated by measuring the H_2 wavelengths in the high-resolution spectrum of the quasar Q~0347-382. Our analysis yielded an estimate for the possible deviation of…