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Related papers: OH Maser sources in W49N: probing differential ani…

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We present a parsec-scale image of the OH maser in the nucleus of the active galaxy IIIZw35, made using the Very Long Baseline Array at a wavelength of 18 cm. We detected two distinct components, with a projected separation of 50 pc (for…

Astrophysics · Physics 2016-08-30 A. S. Trotter , J. M. Moran , L. J. Greenhill , X. -W. Zheng , C. R. Gwinn

We present the results of multi-epoch VERA observations of W49N - OH43.8-0.1 water maser pair. Based on the dual-beam VLBI observation with VERA, we successfully obtained the phase-referenced maps of OH43.8-0.1 with respect to the W49N…

Astrophysics · Physics 2007-05-23 Mareki Honma

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

This Letter reports on initial Expanded Very Large Array (EVLA) observations of the 6035 MHz masers in ON 1. The EVLA data are of good quality, lending confidence in the new receiver system. Nineteen maser features, including six Zeeman…

Astrophysics · Physics 2015-05-13 Vincent L. Fish

Using the Very Long Baseline Array (VLBA) we performed a high resolution OH maser survey in Galactic star-forming regions (SFRs). We observed all the ground state spectral lines: the main lines at 1665 and 1667 MHz and the satellite lines…

Solar and Stellar Astrophysics · Physics 2016-03-28 A. E. Ruiz-Velasco , D. Felli , V. Migenes , B. K. Wiggins

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

Results of monitoring the H$_2$O and OH masers in W44C, located near the cometary HII region G34.3+0.15, are reported. Observations in the water-vapor line at $\lambda = 1.35$ cm were carried out on the 22-meter radio telescope of the…

Astrophysics of Galaxies · Physics 2011-11-22 E. E. Lekht , M. I. Pashchenko , G. M. Rudnitskii

Context: Ground-state OH maser emission from late-type stars is usually polarized and remains a powerful probe of the magnetic field structure in the outer regions of circumstellar envelopes if observed with high angular and spectral…

Astrophysics of Galaxies · Physics 2011-10-11 Paweł Wolak , Marian Szymczak , Eric Gérard

We analyze full-polarization VLBA data of ground-state, main-line OH masers in 18 massive star-forming regions previously presented in a companion paper. The OH masers often arise in the shocked neutral gas surrounding ultracompact Hii…

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

We report full polarimetric VLBA observations of water masers towards the Turner-Welch Object in the W3(OH) high-mass star forming complex. This object drives a synchrotron jet, which is quite exceptional for a high-mass protostar, and is…

Astrophysics of Galaxies · Physics 2016-12-28 C. Goddi , G. Surcis , L. Moscadelli , H. Imai , W. H. T. Vlemmings , H. J. van Langevelde , A. Sanna

We present global VLBI observations of the first-excited state OH masers in the massive star-forming region Onsala 1 (ON 1). The 29 masers detected are nearly all from the 6035 MHz transition, and nearly all are identifiable as Zeeman pair…

Astrophysics of Galaxies · Physics 2010-04-23 Vincent L. Fish , Loránt O. Sjouwerman

We present the results of MERLIN polarization mapping of OH masers at 1665 and 1667 MHz towards the Cepheus A star-forming region. The maser emission is spread over a region of 6 arcsec by 10 arcsec, twice the extent previously detected. In…

Astrophysics · Physics 2009-11-11 A. Bartkiewicz , M. Szymczak , R. J. Cohen , A. M. S. Richards

Full polarization measurements of 1665 and 1667-MHz OH masers at sites of massive star formation have been made with the Parkes 64-m radio telescope. Here we present the resulting spectra for 104 northerly sources. For more than 20 masers…

Astrophysics of Galaxies · Physics 2014-02-12 J. L. Caswell , J. A. Green , C. J. Phillips

We apply the anisotropic resonant scattering model developed to explain the presence of non-Zeeman circular polarization signals recently detected in the $^{12}\mathrm{CO}\;\left(J=2\rightarrow1\right)$ and $\left(J=1\rightarrow0\right)$…

Solar and Stellar Astrophysics · Physics 2015-06-22 Martin Houde

The ATCA has been used to measure positions with arcsecond accuracy for 379 masers at the 22-GHz transition of water. The principal observation targets were 202 OH masers of the variety associated with star formation regions (SFR)s in the…

Astrophysics of Galaxies · Physics 2015-05-18 Shari Breen , James Caswell , Simon Ellingsen , Chris Phillips

We have studied the OH masers in the star forming region, W3(OH), with data obtained from the Very Long Baseline Array (VLBA). The data provide an angular resolution of $\sim$5 mas, and a velocity resolution of 106 m s$^{-1}$. A novel…

Astrophysics · Physics 2008-11-26 R. Ramachandran , A. A. Deshpande , W. M. Goss

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

Using the Very Large Array (VLA), we observed all three of the 6-cm lines of the doublet Pi 1/2, J=1/2 state of OH with sub-arcsecond resolution (about 0.4 arcsec) in W49A. While the spatial distribution and the range in velocities of the…

Astrophysics · Physics 2009-09-29 Patrick Palmer , W. M. Goss

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

We have identified and classified Zeeman pairs in the survey by Argon, Reid, & Menten of massive star-forming regions with 18 cm (2 Pi 3/2, J = 3/2) OH maser emission. We have found a total of more than 100 Zeeman pairs in more than 50…

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