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Related papers: OH (1720 MHz) Masers and Mixed-Morphology Supernov…

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OH(1720 MHz) masers are excellent signposts of interaction between supernova remnants(SNRs) and molecular clouds. Using the GBT and VLA we have surveyed 75 SNRs and six candidates for maser emission. Four new interacting SNRs are detected…

Astrophysics of Galaxies · Physics 2009-11-13 John W. Hewitt , Farhad Yusef-Zadeh

We present the results of GBT observations of all four ground-state hydroxyl (OH) transitions toward 15 supernova remnants (SNRs) which show OH(1720 MHz) maser emission. This species of maser is well established as an excellent tracer of an…

Astrophysics · Physics 2009-11-13 J. W. Hewitt , F. Yusef-Zadeh , M. Wardle

A new class of OH (1720 MHz) masers unaccompanied by main-line transitions have recently been discovered (Frail, Goss and Slysh 1994). These masers lie at the interface between supernova remnants (SNRs) interacting with molecular clouds. We…

Astrophysics · Physics 2007-05-23 F. Yusef-Zadeh , D. A. Roberts , G. Bower , M. Wardle

OH(1720 MHz) masers unaccompanied by 1665/7 MHz line masers have recently been proposed as indicators of the interaction of supernova remnants (SNRs) and molecular clouds. We present a model for the masing region in which water produced in…

Astrophysics · Physics 2007-05-23 Mark Wardle , Farhad Yusef-Zadeh , T. R. Geballe

A survey of the inner 8$^\circ \times 1^\circ$ of the Galactic plane toward the Galactic center has been carried out at the 1720 MHz transition of OH molecule using the VLA in its D configuration with a resolution of…

Astrophysics · Physics 2009-05-20 F. Yusef-Zadeh , W. M. Goss , D. A. Roberts , B. Robinson , D. A. Frail

Compact OH(1720 MHz) masers have proven to be excellent signposts for the interaction of supernova remnants with adjacent molecular clouds. Less appreciated has been the weak, extended OH(1720 MHz) emission which accompanies strong compact…

Astrophysics · Physics 2009-11-13 J. W. Hewitt , F. Yusef-Zadeh , M. Wardle , D. A. Roberts

The W28 supernova remnant is an excellent prototype for observing shocked gas resulting from the interaction of supernova remnants (SNRs) and adjacent molecular clouds (MCs). We present two new signatures of shocked molecular gas in this…

Astrophysics · Physics 2016-08-30 F. Yusef-Zadeh , M. Wardle , D. A. Roberts

We present the results of VLA observations in the ground-state hydroxyl (OH) transition at 1720 MHz toward 20 supernova remnants (SNRs). We detect compact emission from four objects. For three of these objects (G32.8-0.1, G337.8-0.1, and…

Astrophysics · Physics 2009-10-30 Barron Koralesky , D. A. Frail , W. M. Goss , M. J. Claussen , A. J. Green

The environs of three supernova remnants (SNR) with associated OH 1720 MHz masers, G349.7+0.2, CTB 37A and G16.7+0.1, have been surveyed in the CO J=1-0 transition with the 12 Meter Telescope of the NRAO, using the On-The-Fly technique.…

Astrophysics · Physics 2009-10-31 Estela M. Reynoso , Jeffrey G. Mangum

Supernova remnants expanding into adjacent molecular clouds are believed to be sites of cosmic ray acceleration and sources of energetic gamma-rays. Under certain environmental conditions, such interactions also give rise to unusual OH…

Astrophysics · Physics 2009-11-06 Z. Arzoumanian , F. Yusef-Zadeh , T. J. W. Lazio

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

We report new CO observations and a detailed molecular-line study of the mixed morphology (MM) supernova remnant (SNR) G359.1-0.5, which contains six OH (1720 MHz) masers along the radio shell, indicative of shock-cloud interaction.…

Astrophysics of Galaxies · Physics 2020-02-26 L. K. Eppens , E. M. Reynoso , J. Lazendic-Galloway , J. A. Combi , J. F. Albacete Colombo , -

We present molecular-line observations at millimetre, centimetre and infrared wavelengths of the region containing OH(1720 MHz) masers in the supernova remnant (SNR) G349.7+0.2, using the Australia Telescope (AT) Mopra antenna, the…

Astrophysics · Physics 2011-04-20 J. S. Lazendic , M. Wardle , J. B. Whiteoak , M. G. Burton , A. J. Green

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

We have undertaken a study of radio and infrared molecular-line emission towards several SNRs in order to investigate molecular signatures of SNR shocks, and to test models for OH maser production in SNRs. Here we present results on…

Astrophysics · Physics 2007-05-23 J. S. Lazendic , M. Wardle , A. J. Green , J. B. Whiteoak , M. G. Burton

Sgr B2 is a well-known star forming molecular cloud complex in the Galactic center region showing evidence of high energy activity as traced by the K$\alpha$ neutral FeI line at 6.4 keV, as well as GeV and TeV $\gamma$-ray emission. Here we…

High Energy Astrophysical Phenomena · Physics 2016-03-23 F. Yusef-Zadeh , W. Cotton , M. Wardle , H. Intema

We present Very Large Array (VLA) radio interferometry observations of the 1720 MHz OH masers in the Galactic Center (GC). Most 1720 MHz OH masers arise in regions where the supernova remnant Sgr A East is interacting with the interstellar…

Astrophysics · Physics 2009-11-13 L. O. Sjouwerman , Y. M. Pihlstrom

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

Astrophysics · Physics 2009-11-13 Korinne E. McDonnell , Alan E. Vaughan , Mark Wardle

OH(1720 MHz) masers are created by the interaction of supernova remnants with molecular clouds. These masers are pumped by collisions in warm, shocked molecular gas with OH column densities in the range 10^{16}--10^{17} cm^{-2}. Excitation…

Astrophysics of Galaxies · Physics 2015-06-04 Mark Wardle , Korinne McDonnell

We present observations of molecular gas made with the 15-m James Clark Maxwell Telescope toward the sites of OH(1720 MHz) masers in three supernova remnants: W28, W44 and 3C391. Maps made in the 12CO J=3-2 line reveal that the OH masers…

Astrophysics · Physics 2009-10-30 Dale A. Frail , George F. Mitchell
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