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The Atacama Pathfinder Experiment (APEX) 12m telescope was used to observe the N=1-0, J=0-1 ground state transitions of OH+ at 909.1588 GHz with the CHAMP+ heterodyne array receiver. Two blended hyperfine structure transitions were detected…

Astrophysics of Galaxies · Physics 2015-05-18 F. Wyrowski , K. M. Menten , R. Guesten , A. Belloche

We have carried out a sensitive search for OH (1720 MHz) masers in the Large Magellanic Cloud (LMC) toward five regions using the Australia Telescope Compact Array (ATCA). Our source list includes the 30 Doradus region, and four supernova…

Astrophysics · Physics 2009-11-10 C. L. Brogan , W. M. Goss , J. Lazendic , A. J. Green

We report one OH 1665-MHz detection in new observations with the NSF's Karl G. Jansky Very Large Array. To the authors' knowledge, this is the first OH maser detection in M33. The source occurs at a position of $\alpha=23.50069(9)^{\circ}$…

Astrophysics of Galaxies · Physics 2018-02-01 Eric Koch , Erik Rosolowsky , Megan C. Johnson , Amanda A. Kepley , Adam Leroy

We have used the Australia Telescope Compact Array (ATCA) to make a sensitive search for maser emission from the 4765-MHz transition of OH towards a sample of 55 star formation regions. Maser emission with peak flux densities in excess of…

Astrophysics · Physics 2007-05-23 R. Dodson , S. Ellingsen

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

Massive O-type stars play a dominant role in our Universe, but many of their properties remain poorly constrained. In the last decade magnetic fields have been detected in all Galactic members of the distinctive Of?p class, opening the door…

Solar and Stellar Astrophysics · Physics 2017-05-24 S. Bagnulo , Y. Naze , I. D. Howarth , N. Morrell , J. S. Vink , G. A. Wade , N. Walborn , M. Romaniello , R. Barba

We measure carbon radio recombination line (RRL) emission at 5.3 GHz toward four HII regions with the Green Bank Telescope (GBT) to determine the magnetic field strength in the photodissociation region (PDR) that surrounds the ionized gas.…

Astrophysics of Galaxies · Physics 2016-01-13 Dana S. Balser , D. Anish Roshi , S. Jeyakumar , T. M. Bania , Benjamin T. Montet , J. A. Shitanishi

Radio quasar sightlines with strong MgII absorption lines display statistically enhanced Faraday Rotation Measures (RM) indicating the presence of additional magneto-active plasma with respect to sightlines free of such absorption. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 M. L. Bernet , F. Miniati , S. J. Lilly

The majority of the observed planetary nebulae exhibit elliptical or bipolar structures. Theoretical modeling has indicated that magnetically collimated jets may be responsible for the formation of the non-spherical planetary nebulae. The…

Solar and Stellar Astrophysics · Physics 2015-05-14 N. Amiri , W. H. T. Vlemmings , H. J. van Langevelde

Context: OH masers trace diverse physical processes, from the expanding envelopes around evolved stars to star-forming regions or supernovae remnants. Aims: We identify the ground-state OH masers at 18cm wavelength in the area covered by…

High-resolution VLA observations of 1720 MHz OH maser emission from Sgr A East and the circumnuclear disk with spatial and spectral resolutions of $\approx$ 2\dasec5 $\times$ 1\dasec3 and 0.27 \kms are reported. This follow-up observational…

Astrophysics · Physics 2009-10-30 F. Yusef-Zadeh , D. A. Roberts , W. M. Goss , D. A. Frail , A. J. Green

We present the first view of the magnetic field structure in the OH shell of the extreme OH/IR star OH 26.5+0.6. MERLIN interferometric observations of this object were obtained in December 1993 in full polarisation, at 1612, 1665 and 1667…

Astrophysics of Galaxies · Physics 2015-05-18 S. Etoka , P. J. Diamond

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

We present models for the chemistry in gas moving towards the ionization front of an HII region. When it is far from the ionization front, the gas is highly depleted of elements more massive than helium. However, as it approaches the…

Astrophysics · Physics 2009-11-13 S. Viti , T. W. Hartquist , P. C. Myers

We report on the first space-VLBI observations of the OH masers in two main-line OH transitions at 1665 and 1667 MHz. The observations involved the space radio telescope on board the Japanese satellite HALCA and an array of ground radio…

Astrophysics · Physics 2007-05-23 V. I. Slysh , M. A. Voronkov , I. E. Val'tts , V. Migenes , K. M. Shibata , T. Umemoto

OH absorption against PSR B1718-35 at (l,b) =351.688,+0.671 has been discovered at 1665 and 1667 MHz using the Green Bank Telescope. The absorption appears to arise at the interface of an HII region and a molecular cloud which are likely…

Astrophysics · Physics 2009-11-13 Anthony H. Minter

We present initial results of a project to measure mean longitudinal magnetic fields in a group of sdB/OB/O stars. The project was inspired by the discovery of three super-metal-rich sdOB stars, each having metals (e.g. Ti, V) enhanced by…

Astrophysics · Physics 2007-05-23 S. J. O'Toole , S. Jordan , S. Friedrich , U. Heber

We present a new database of circumstellar OH masers at 1612, 1665, and 1667 MHz in the Milky Way galaxy. The database (version 2.4) contains 13655 observations and 2341 different stars detected in at least one transition. Detections at…

Solar and Stellar Astrophysics · Physics 2015-10-14 D. Engels , F. Bunzel

Bright OH megamaser galaxies, radiating 1667/1665 MHz lines, could be detected at redshifts from z from 1 to 3 in moderate integration times with existing radio telescopes. The superluminous FIR galaxies that host the megamasers are…

Astrophysics · Physics 2007-05-23 F. H. Briggs

We present the results of a survey for OH maser emission at 1612 MHz from dust-enshrouded AGB stars and supergiants in the LMC and SMC, with the Parkes radio telescope, aimed at deriving the speed of the superwind from the double-peaked OH…

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