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We have used the Australia Telescope Compact Array (ATCA) to search for a number of centimetre wavelength methanol transitions which are predicted to show weak maser emission towards star formation regions. Sensitive, high spatial and…

Astrophysics of Galaxies · Physics 2016-11-15 Antony Chipman , Simon Ellingsen , Andrej Sobolev , Dinah Cragg

We present the results of a high sensitivity survey for 6.7 GHz methanol masers towards 22 GHz water maser using the 100 m Efflesberg telescope. A total of 89 sources were observed and 10 new methanol masers were detected. The new…

Astrophysics · Physics 2010-01-28 Y. Xu , J. J. Li , K. Hachisuka , J. D. Pandian , K. M. Menten , C. Henkel

Observing inversion lines of ammonia (NH3), complemented by rotational lines of NH3 and other molecular species, provides stringent constraints on potential variations of the proton-to-electron mass ratio. While a limit of one part per…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-07 C. Henkel , K. M. Menten , M. T. Murphy , V. V. Flambaum , S. A. Levshakov , A. V. Lapinov , P. Molaro , J. A. Braatz

We report the discovery of periodic flares of 6.7GHz methanol maser in the young massive stellar object G22.357+0.066. The target was monitored in the methanol maser line over 20 months with the Torun 32m telescope. The emission was also…

Astrophysics of Galaxies · Physics 2015-05-28 M. Szymczak , P. Wolak , A. Bartkiewicz , H. J. van Langevelde

MERLIN observations of 6.668-GHz methanol and both 6.031- and 6.035-GHz hydroxyl (OH) emission from the massive star-formation region ON1 are presented. These are the first methanol observations made in full polarization using 5 antennas of…

Astrophysics · Physics 2009-11-13 J. A. Green , A. M. S. Richards , W. H. T. Vlemmings , P. Diamond , R. J. Cohen

Context: We investigated the molecular gas associated with 6.7 GHz methanol masers throughout the Galaxy using a J=1-0 transition of the CO isotopologues. Methods:Using the 13.7-meter telescope at the Purple Mountain Observatory (PMO), we…

Solar and Stellar Astrophysics · Physics 2014-09-05 Zhiyuan Ren , Yuefang Wu , Tie Liu , Lixin Li , Di Li , Binggang Ju

We present the results of a targeted 3-mm spectral line survey towards the eighty-three 6.67 GHz methanol maser selected star forming clumps observed by Purcell et al. 2006. In addition to the previously reported measurements of HCO+ (1 -…

We present results on simultaneous observations of Class~I methanol masers at 25, 36, and 44 GHz towards 22 Galactic targets carried out with the Effelsberg 100-m telescope. The study investigates relations between the hyperfine (HF)…

The detection of the 6.7 GHz line of methanol (CH3OH) is reported for the first time toward an object beyond the Magellanic Clouds. Using the Effelsberg 100 m telescope, two absorption features were identified toward the Seyfert 2 galaxy…

Astrophysics · Physics 2009-11-13 C. M. V. Impellizzeri , C. Henkel , A. L. Roy , K. M. Menten

We have used the Australia Telescope National Facility Mopra 22m millimetre telescope to search for emission from the 85.5-GHz and 86.6-GHz transitions of methanol. The search was targeted towards 22 star formation regions which exhibit…

Astrophysics · Physics 2009-11-07 S. P. Ellingsen , D. M. Cragg , V. Minier , E. Muller , P. D. Godfrey

Strong evidence has recently emerged for a variation in the fine structure constant, $\alpha\equiv e^2/\hbar c$, over the history of the Universe. This was concluded from a detailed study of the relative positions of redshifted optical…

Astrophysics · Physics 2009-11-10 S. J. Curran , N. Kanekar , J. K. Darling

We present a survey for low-ionization metal absorption line systems towards 17 QSOs at redshifts z_em=5.8-6.4. Nine of our objects were observed at high resolution with either Keck/HIRES or Magellan/MIKE, and the remainder at moderate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 George D. Becker , Wallace L. W. Sargent , Michael Rauch , Alexander P. Calverley

Emission from the 6.7 GHz methanol maser transition is very strong, is relatively stable, has small internal motions, and is observed toward numerous massive star-forming regions in the Galaxy. Our goal is to perform high-precision…

Astrophysics of Galaxies · Physics 2015-05-14 K. L. J. Rygl , A. Brunthaler , M. J. Reid , K. M. Menten , H. J. van Langevelde , Y. Xu

Spectra of 6.7 GHz methanol masers from 21 pointings of known star-forming regions are reported. The C-band observations, using the Green Bank Telescope in full Stokes mode, have measured how polarization properties vary across the maser…

Astrophysics of Galaxies · Physics 2026-05-19 Paul Fallon , Derck P. Smits

We report simultaneous single-dish surveys of 22 GHz H2O and 44 and 95 GHz class I CH3OH masers toward 299 Red MSX Sources in the protostellar stage. The detection rates are 45% at 22 GHz, 28% at 44 GHz, and 23% at 95 GHz. There are 15, 53,…

Astrophysics of Galaxies · Physics 2018-05-23 Chang-Hee Kim , Kee-Tae Kim , Yong-Sun Park

The polarized emission of astrophysical masers, especially OH and methanol lines, is an effective tool to study the magnetic field in high-mass star-forming regions. The magnetic field strength measurement via the Zeeman effect of OH maser…

Astrophysics of Galaxies · Physics 2025-08-21 A. Kobak , G. Surcis , A. Bartkiewicz , W. H. T. Vlemmings , M. Szymczak

VLA 1.4 GHz (rms noise ~0.012 mJy) and MIPS 24 and 70 micron (rms noise ~0.02 and ~1.7 mJy, respectively) observations covering the 2 square degree COSMOS field are combined with an extensive multi-wavelength data set to study the evolution…

We present results of the investigations of the properties of the methanol $J_1 - J_0$ A$^{-+}$ line series motivated by the recent serendipitous detection of the maser emission in the $14_1 - 14_0$ A$^{-+}$ line at 349~GHz in S255IR-SMA1…

Astrophysics of Galaxies · Physics 2022-03-30 Svetlana V. Salii , Igor I. Zinchenko , Sheng-Yuan Liu , Andrej M. Sobolev , Artis Aberfelds , Yu-Nung Su

Quasar absorption spectra at 21-cm and UV rest-wavelengths are used to estimate the time variation of x=alpha^2 g_p mu, where alpha is the fine structure constant, g_p the proton g factor, and m_e/m_p=mu the electron/proton mass ratio. Over…

Astrophysics · Physics 2009-08-18 P. Tzanavaris , J. K. Webb , M. T. Murphy , V. V. Flambaum , S. J. Curran

We present high resolution (arcsecond or better) observations made with the Karl G. Jansky Very Large Array of 123 radio-loud quasars with redshifts in the range $2.5 \leq z \leq 5.28$ that form a complete flux limited sample ($\geq 70$ mJy…

Astrophysics of Galaxies · Physics 2014-06-19 Doug B. Gobeille , John F. C. Wardle , C. C. Cheung