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Related papers: OH in Messier 82

200 papers

We have used the NRAO Very Long Baseline Array (VLBA) to image OH(1720 MHz) masers in the supernova remnants W28 and W44 at a resolution of 40 mas. We also used MERLIN to observe the same OH(1720 MHz) masers in W44 at a resolution of 290 x…

Astrophysics · Physics 2009-10-31 M. J. Claussen , W. M. Goss , D. A. Frail , K. Desai

We present high spatial resolution observations of ground-state OH masers achieved with the Australia Telescope Compact Array (ATCA). These observations targeted 253 pointing centres containing OH maser candidates at all four ground-state…

OH masers at 1720 MHz have proven to be excellent indicators of interactions between supernova remnants and molecular clouds. OH excitation calculations suggest that the 6049 MHz OH maser line is excited for higher column densities than for…

Astrophysics · Physics 2008-10-28 Korinne E. McDonnell , Mark Wardle , Alan E. Vaughan

The ATCA, MERLIN and VLA interferometers were used to measure the absolute positions of 35 6.7 GHz methanol masers to subarcsecond or higher accuracy. Our measurements represent essential preparatory data for Very Long Baseline…

Astrophysics of Galaxies · Physics 2015-05-14 Y. Xu , M. A. Voronkov , J. D. Pandian , J. J. Li , A. M. Sobolev , A. Brunthaler , B. Ritter , K. M. Menten

The collisionally pumped, ground-state 1720 MHz maser line of OH is widely recognized as a tracer for shocked regions and observed in star forming regions and supernova remnants. Whereas some lines of excited states of OH have been detected…

We present the serendipitous detection of the two main OH maser lines at 1667 and 1665 MHz associated with IRAS 10597+5926 at z = 0.19612 in the untargeted Apertif Wide-area Extragalactic Survey (AWES), and the subsequent measurement of the…

OH megamasers (OHMs) are rare, luminous masers found in gas-rich major galaxy mergers. In untargeted neutral hydrogen ($\mathrm{HI}$) emission-line surveys, spectroscopic redshifts are necessary to differentiate the $\lambda_\text{rest}=18$…

Astrophysics of Galaxies · Physics 2021-04-15 Hayley Roberts , Jeremy Darling , Andrew J. Baker

We present high angular resolution observations of OH maser emission towards the high-mass star forming region IRAS 06056+2131. The observations were carried out using the UK radio interferometer array, Multi-Element Radio Linked…

Solar and Stellar Astrophysics · Physics 2021-01-19 Mohamed Said darwish , Anita M. S. Richards , Sandra Etoka , Khaled Edris , Somaya Saad , Mohamed Beheary , Gary Fullar

The OH main line masers in circumstellar shells were observed with astrometric VLBI in order to accurately determine the position of the star, as well as its motion, including the parallax. Results are presented on 4 Mira stars monitored…

Astrophysics · Physics 2007-05-23 Wouter Vlemmings , Huib Jan van Langevelde , Phil Diamond

A survey for H2O megamaser emission from 354 active galaxies has resulted in the detection of 10 new sources, making 16 known altogether. The galaxies surveyed include a distance-limited sample (covering Seyferts and LINERs with recession…

Astrophysics · Physics 2009-10-30 J. A. Braatz , A. S. Wilson , C. Henkel

Results of observations of the maser sources toward the W33C region (G12.8-0.2) carried out on the 22-m radio telescope of the Pushchino Radio Astronomy Observatory in the 1.35-cm H2O line and on the Large radio telescope in Nancay (France)…

Astrophysics of Galaxies · Physics 2015-06-11 P. Colom , E. E. Lekht , M. I. Pashchenko , G. M. Rudnitskij

We report on a second epoch of VLBA observations of the 1665 and 1667 MHz OH masers in the massive star-forming region W75 N. We find evidence to confirm the existence of very strong (~40 mG) magnetic fields near source VLA 2. The masers…

Astrophysics · Physics 2008-11-26 Vincent L. Fish , Mark J. Reid

We present global VLBI observations of the first-excited state OH masers in the massive star-forming region Onsala 1 (ON 1). The 29 masers detected are nearly all from the 6035 MHz transition, and nearly all are identifiable as Zeeman pair…

Astrophysics of Galaxies · Physics 2010-04-23 Vincent L. Fish , Loránt O. Sjouwerman

Circumstellar OH maser lines are useful for studying the dynamics of the circumstellar envelope (CSE) around evolved stars. This study aims to identify CSEs around cold stars, which exhibit deviations from the spherical expansion, by…

Solar and Stellar Astrophysics · Physics 2024-12-03 Jia-Yong Xie , Jun-ichi Nakashima , Yong Zhang

From targeted observations of ground-state OH masers towards 702 Multibeam (MMB) survey 6.7-GHz methanol masers, between Galactic longitudes 186$^{\circ}$ through the Galactic centre to 20$^{\circ}$, made as part of the `MAGMO' project, we…

Astrophysics of Galaxies · Physics 2020-01-29 C. S. Ogbodo , J. A. Green , J. R. Dawson , S. L. Breen , S. A. Mao , N. M. McClure-Griffiths , T. Robishaw , L. Harvey-Smith , .

We present VLA observations in the hydroxyl line OH(1720 MHz) towards the supernova remnant W28. These high resolution images show a more extensive distribution of 1720 MHz emission than had previously been suspected from earlier…

Astrophysics · Physics 2009-10-22 D. A. Frail , W. M. Goss , V. I. Slysh

Discovered in 1995 at the Caltech Submillimeter Observatory (CSO), the vibrationally-excited water maser line at 658 GHz (455 micron) is seen in oxygen-rich giant and supergiant stars. Because this maser can be so strong (up to thousands of…

Astrophysics · Physics 2015-03-30 T. R. Hunter , K. H. Young , R. D. Christensen , M. A. Gurwell

The 22 GHz H_2O masers in the circumstellar envelope of the Mira variable star U Her have been observed with MERLIN using a phase referencing technique to determine accurate astrometric positions. The positions were compared with the…

Astrophysics · Physics 2009-11-07 W. H. T. Vlemmings , H. J. van Langevelde , P. J. Diamond

We report on high spatial resolution observations, using the Australia Telescope Compact Array (ATCA), of ground-state OH masers. These observations were carried out toward 196 pointing centres previously identified in the Southern Parkes…

We report the detection of a new H_2O megamaser in the Seyfert 2 galaxy Mrk 348 with the MPIfR 100 m telescope in Effelsberg. With an apparent isotropic luminosity of L_H2O ~ 420 L_sun the maser is the third most luminous maser discovered…