English
Related papers

Related papers: High Spectral and Spatial Resolution Observations …

200 papers

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

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

OH(1720 MHz) masers permit direct measurements of the magnetic field strength at the Galactic Centre, and their angular broadening constrains models for the medium that scatters radio waves in the central 100 pc of the Galaxy. As the 1720…

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

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(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 a synthesis of a number of recent observations in the near-IR H_2 and [Fe II] lines, OH (1720 MHz) maser line and various radio continuum measurements using the NICMOS of the HST, UNSWIRF on the AAT and the VLA. These…

Astrophysics · Physics 2007-05-23 F. Yusef-Zadeh , S. Stolovy , M. Burton , M. Wardle , F. Melia , J. Lazio , N. Kassim

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

We present the first variability study of the 1720 MHz OH masers located in the Galactic Center. Most of these masers are associated with the interaction between the supernova remnant SgrAEast and the interstellar medium, but a few masers…

Astrophysics of Galaxies · Physics 2015-05-28 Y. M. Pihlström , L. O. Sjouwerman , R. A. Mesler

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 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

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

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

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

Radio surveys of supernova remnants (SNRs) in the Galaxy have uncovered 19 SNRs accompanied by OH maser emission at 1720 MHz. This unusual class of maser sources is suggested to be produced behind a shock front from the expansion of a…

Astrophysics · Physics 2009-11-07 F. Yusef-Zadeh , M. Wardle , J. Rho , M. Sakano

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 have obtained maps of the molecular emission within the central five arcminutes (12 pc) of the Galactic center (GC) in selected molecular tracers: SiO(2-1), HNCO(5_{0,5}-4_{0,4}), and the J=1-->0 transition of H^{13}CO+, HN^{13}C, and…

Astrophysics of Galaxies · Physics 2015-05-20 M. A. Amo-Baladrón , J. Martín-Pintado , S. Martín

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 have detected the v=1-0 S(1) (2.1218 um) and v=2-1 S(1) (2.2477 um) lines of H_2 in the Galactic centre, in a 90 x 27 arcsec region between the northeastern boundary of the non-thermal source, Sgr A East, and the giant molecular cloud…

We have found a bar of shocked molecular hydrogen (H2) towards the OH(1720 MHz) maser located at the projected intersection of supernova remnant (SNR) G359.1-0.5 and the nonthermal radio filament, known as the Snake. The H2 bar is well…

We report the first study of OH(1720 MHz) masers in the LMC in order to probe regions where supernova remnants interact with adjacent molecular clouds. Using the ATCA, we observed four sources in the LMC and detected a single OH(1720 MHz)…

Astrophysics · Physics 2007-05-23 D. A. Roberts , F. Yusef-Zadeh
‹ Prev 1 2 3 10 Next ›