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Related papers: Strong magnetic field in W75N OH maser flare

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A flare of maser radio emission in the OH-line 1665 MHz has been discovered in the star forming region W75 N in 2003, with the flux density of about 1000 Jy. At the time it was the strongest OH maser detected during the whole history of…

Astrophysics · Physics 2009-11-10 A. V. Alakoz , V. I. Slysh , M. V. Popov , I. E. Val'tts

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

W75N is a star-forming region containing various ultracompact HII regions and OH, water, and methanol maser emission. Our VLBA map shows that the OH masers are located in a thin disk rotating around an O-star which is the exciting star of…

The star-forming region W75N hosts bright OH masers that are observed to be variable. We present observations taken in 2008 of the ground-state OH maser transitions with the Very Long Baseline Array (VLBA) and the Multi-Element Radio-Linked…

Astrophysics of Galaxies · Physics 2015-05-28 Vincent L. Fish , Malcolm Gray , W. M. Goss , A. M. S. Richards

We have observed the OH (1720 MHz) line in five galactic SNRs with the VLA to measure their magnetic field strengths using the Zeeman effect. We detected all 12 of the bright ($S_{\nu} > 200$ mJy) OH (1720 MHz) masers previously detected by…

Astrophysics · Physics 2009-10-31 C. L. Brogan , D. A. Frail , W. M. Goss , T. H. Troland

We aim to detect the magnetic field and infer its properties around four AGB stars using H$_2$O maser observations. The sample we observed consists of the following sources: the semi-regular variable RT Vir and the Mira variables AP Lyn, IK…

Solar and Stellar Astrophysics · Physics 2015-06-15 M. L. Leal-Ferreira , W. H. T. Vlemmings , A. Kemball , N. Amiri

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

We present data of proper motions of OH masers in the massive star-forming regions ON 1, K3-50, and W51 Main/South. OH maser motions in ON 1 are consistent with expansion at approximately 5 km/s, likely tracing the expanding ultracompact H…

Astrophysics · Physics 2009-11-13 Vincent L. Fish , Mark J. Reid

A debated topic in star formation theory is the role of magnetic fields during the protostellar phase of high-mass stars. It is still unclear how magnetic fields influence the formation and dynamics of massive disks and outflows. Most…

Solar and Stellar Astrophysics · Physics 2015-05-27 G. Surcis , W. H. T. Vlemmings , S. Curiel , B. Hutawarakorn Kramer , J. M. Torrelles , A. P. Sarma

Context: The role of magnetic fields during high-mass star formation is a matter of fierce debate, yet only a few direct probes of magnetic field strengths are available. Aims: The magnetic field is detected in a number of massive…

Astrophysics · Physics 2009-11-13 W. H. T. Vlemmings

The role of magnetic fields during the protostellar phase of high-mass star-formation is a debated topic. In particular, it is still unclear how magnetic fields influence the formation and dynamic of disks and outflows. Most current…

Solar and Stellar Astrophysics · Physics 2015-05-14 G. Surcis , W. H. T. Vlemmings , R. Dodson , H. J. van Langevelde

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

Context. Maser emission is a strong tool for studying high mass star forming regions and their evolutionary stages. OH masers in particular can trace the circumstellar material around protostars and determine their magnetic field strengths…

Astrophysics of Galaxies · Physics 2017-12-13 K. A. Edris , G. A. Fuller , S. Etoka , R. J. Cohen

We present VLBA observations of 1667 MHz OH maser emission from the massive star formation region G5.89-0.39. The observations were phase referenced allowing the absolute positions of the masers to be obtained. The 1667 MHz masers have…

Astrophysics · Physics 2008-11-26 D. P. Stark , W. M. Goss , E. Churchwell , V. L. Fish , I. M. Hoffman

(Abridged) Recently, the magnetic field induced Zeeman splitting was measured for the strongest known 6.7 GHz methanol maser, which arises in the massive star forming region G09.62+0.20. This maser is one of a handful of periodically…

Astrophysics of Galaxies · Physics 2015-05-13 W. H. T. Vlemmings , S. Goedhart , M. J. Gaylard

We have measured the Zeeman splitting of OH megamaser emission at 1667 MHz from five (ultra)luminous infrared galaxies ([U]LIRGs) using the 305 m Arecibo telescope and the 100 m Green Bank Telescope. Five of eight targeted galaxies show…

Astrophysics · Physics 2009-11-13 Timothy Robishaw , Eliot Quataert , Carl Heiles

The massive star-forming region G11.904-0.141 is one of only 11 sources to show maser emission in the highly-excited 13441 MHz transition of OH. VLBA observations of the 1665, 1667, 4765, and 13441 MHz transitions of OH toward G11.904-0.141…

Astrophysics · Physics 2009-11-13 Vincent L. Fish

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 , .

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 phase-referenced polarimetric observations towards the W51 complex were carried out in March 2006 in the Class II methanol maser transition at 6.668 GHz and three of the four excited OH maser hyperfine transitions at 6 GHz. Methanol…

Astrophysics of Galaxies · Physics 2015-06-04 Sandra Etoka , Malcolm D. Gray , Gary A. Fuller
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