English
Related papers

Related papers: OH(1720 MHz) Masers at the Galactic Centre

200 papers

Class I methanol masers are collisionally pumped and are generally correlated with outflows in star forming sites in the Galaxy. Using the VLA in its A-array configuration, we present a spectral line survey to identify methanol…

Astrophysics of Galaxies · Physics 2016-12-14 W. Cotton , F. Yusef-Zadeh

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

We have observed six high-mass star-forming regions in the 2 Pi 3/2, J = 7/2 lines of OH using the GBT in order to investigate whether the magnetic field, and hence the density, measured in absorption differs from that implied by maser…

Astrophysics · Physics 2009-11-10 Vincent L. Fish , Mark J. Reid , Karl M. Menten

We study the structure and kinematics of the OH-streamer and the +80 km/s cloud and their interactions with the circumnuclear disk (CND) and with other molecular clouds in the vicinity of the Galactic centre (GC), and we map OH absorption…

Astrophysics of Galaxies · Physics 2015-11-04 Roland Karlsson , Aage Sandqvist , Kambiz Fathi , Sergio Martín

Mapping and monitoring observations of SiO maser sources near the Galactic center were made with the Nobeyama 45-m telescope at 43 GHz. Rectangular mapping an area of approximately 200'' x 100''$ in a 30'' grid, and triangular mapping in a…

Astrophysics · Physics 2015-06-24 Shuji Deguchi , Takahiro Fujii , Makoto Miyoshi , Jun-ichi Nakashima

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

We have searched for 22 GHz H2O and 43/86/129 GHz SiO masers in bright IRAS point sources in the SMC and LMC, to test whether the kinematics of the mass loss from these stars depends on metallicity. H2O masers were detected in the red…

Astrophysics · Physics 2009-11-06 Jacco Th. van Loon , Albert A. Zijlstra , Valentin Bujarrabal , Lars-Ake Nyman

We demonstrate that the observed characteristics of the 5 cm OH masers in star-forming regions can be explained with the same model and the same parameters as the 18 cm and the 6 cm OH masers. In our already published study of the 18 cm and…

Astrophysics · Physics 2009-10-31 K. G. Pavlakis , N. D. Kylafis

We report on a large 44 GHz ($7_0-6_1$ A$^+$) methanol (CH$_3$OH) maser survey of the Galactic Center (GC). The Karl G. Jansky Very Large Array was used to search for CH$_3$OH maser emission covering a large fraction of the region around…

Solar and Stellar Astrophysics · Physics 2016-12-07 Bridget McEwen , Loránt Sjouwerman , Ylva Pihlström

Full-polarization MERLIN and VLBA observations of the 1720-MHz maser emission from the OH molecule in the supernova remnant W44 are presented. Zeeman splitting has been directly resolved between right- and left-circularly polarized spectra…

Astrophysics · Physics 2009-11-10 Ian M. Hoffman , W. M. Goss , C. L. Brogan , M. J. Claussen

We have observed the central 45' region of the Galaxy at 620 MHz band of the Giant Metrewave Radio Telescope (GMRT) in radio continuum, and measured the polarisation properties of 64 small diameter background extragalactic sources seen…

Astrophysics · Physics 2007-05-23 Subhashis Roy

Several new main line OH masers have been detected in the nearby starburst galaxy M82. Eight masers have been detected to 5 sigma, six of which are new detections. Observations covering both the 1665 and 1667 MHz lines with both the Very…

Astrophysics · Physics 2007-05-23 M. K. Argo , A. Pedlar , T. W. B. Muxlow , R. J. Beswick , S. Aalto , K. Wills , R. Booth

We have made angular broadening measurements in the satellite line of the OH molecule at 1612 MHz of 8 OH/IR stars located near the Galactic Center with the Very Large Array. Early observations with the Very Long Baseline Array had revealed…

Astrophysics · Physics 2009-10-22 D. A. Frail , P. J. Diamond , J. M. Cordes , H. J. Van Langevelde

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

The first images of 6.7-GHz methanol masers in the massive star-forming regions DR21(OH) and DR21(OH)N are presented. By measuring the shapes, radial velocities and polarization properties of these masers it is possible to map out the…

Astrophysics · Physics 2009-11-13 L. Harvey-Smith , R. Soria-Ruiz , A. Duarte-Cabral , R. J. Cohen

We present the Australia Telescope Compact Array (ATCA) observations of the SiO masers in the Galactic center in transitions of v=1, J=2--1 at 86 GHz and v=1, J=1--0 at 43 GHz. Two 86-GHz SiO masers were detected within the central parsec,…

Astrophysics of Galaxies · Physics 2010-07-28 Juan Li , Tao An , Zhi-Qiang Shen , Atsushi Miyazaki

Full-polarization MERLIN and VLBA observations of the 1720 MHz maser emission from the OH molecule in the supernova remnant W28 are presented. Zeeman splitting (|B| \approx 0.75 mG) has been directly resolved between right- and…

Astrophysics · Physics 2009-11-10 Ian M. Hoffman , W. M. Goss , C. L. Brogan , M. J. Claussen

The southern maser site OH 300.969+1.147 has been studied using the Long Baseline Array of the Australia Telescope National Facility. The 1665- and 1667-MHz hydroxyl ground-state transitions were observed simultaneously. A series of maps…

Astrophysics of Galaxies · Physics 2015-05-13 J. L. Caswell , B. Hutawarakorn Kramer , J. E. Reynolds

MERLIN and VLBA observations of the 1720 MHz maser emission from the OH molecule in the supernova remnant IC443 are presented. Based on MERLIN data with a resolution of 160 mas, the deconvolved sizes of the maser sources are in the range 90…

Astrophysics · Physics 2009-11-07 Ian M. Hoffman , W. M. Goss , C. L. Brogan , M. J Claussen , A. M. S. Richards

We have detected the two 18cm OH satellite lines from the $z \sim 0.247$ source PKS1413+135, the 1720 MHz line in emission and the 1612 MHz line in absorption. The 1720 MHz luminosity is $L_{\rm OH} \sim 354 L_\odot$, more than an order of…

Astrophysics · Physics 2008-11-26 Nissim Kanekar , Jayaram N. Chengalur , Tapasi Ghosh