相关论文: Polarization properties of OH masers in AGB and po…

(Abridged) The goal of this work is to investigate if SiO, H2O and HCN maser emission within the ALMA frequency range can be detected with observable levels of fractional linear polarization in the regime where the Zeeman frequency (gOmega)…

General solutions of the maser polarization problem are presented for arbitrary absorption coefficients. The results are used to calculate polarization for masers permeated by magnetic fields with arbitrary values of \xB, the ratio of…

We conducted radio observations searching for OH 18-cm maser emission from a sample of 169 unclassified MIPSGAL compact Galactic bubbles. These sources are thought to be the circumstellar envelopes of different kinds of evolved stars. Our…

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…

We investigated the main-line spectral evolution with shell thickness of oxygen rich AGB stars. The study is based on a sample of 30 sources distributed along the IRAS colour-colour diagram. The sources were chosen to trace the Miras with…

Our aim is to characterize the polarized continuum emission properties including intensity, polarization position angle, and polarization percentage of Sgr A* at $\sim$100 (3.0 mm), $\sim$230 (1.3 mm), $\sim$345 (0.87 mm), $\sim$500 (0.6…

Through polarization observations, circumstellar masers are excellent probes of the magnetic field in the envelopes of late-type stars. Whereas observations of the polarization of the SiO masers close to the star and on the OH masers much…

Full polarization measurements of 1665 and 1667-MHz OH masers at 261 sites of massive star formation have been made with the Parkes radio telescope. Here we present the resulting spectra for 157 southern sources, complementing our…

We present new optical broad-band (UBVRI) aperture polarimetric observations of 53 post-asymptotic giant branch (AGB) stars selected to exhibit a large near-infrared excess. 24 out of the 53 stars (45% of our sample) are presented for the…

We study the polarization of the SiO maser emission in a representative sample of evolved stars in order to derive an estimate of the strength of the magnetic field, and thus determine the influence of this magnetic field on evolved stars.…

Circumstellar OH maser lines are useful for studying the dynamics of the circumstellar envelope (CSE) around evolved stars. This study aims to identify CSEs around cold stars, which exhibit deviations from the spherical expansion, by…

We have monitored the SiO (v = 1, J = 2 -> 1) maser polarization in 17 variable stars (Miras, OH-IR stars, and supergiants) to investigate the long-term persistence of masers. The 8 epochs of observations span 2.5 years, thereby sampling…

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…

We present a survey of the polarization properties of mm-wavelength methanol masers, comprising both classes, and transitions from 84.5 to 157.0 GHz. Linear polarization is found in more than half of the observed objects, and circular…

We present Submillimeter Array observations of high frequency SiO masers around the supergiant VX Sgr and the semi-regular variable star W Hya. The J=5-4, v=1 28SiO and v=0 29SiO masers of VX Sgr are shown to be highly linearly polarized…

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…

Polarisation observations of masers in the circumstellar envelopes (CSEs) around Asymptotic Giant Branch (AGB) stars have revealed strong magnetic fields. However, masers probe only specific lines-of-sight through the CSE. Non-masing…

High resolution maps of maser emission provide very detailed information on processes occurring in circumstellar envelopes of late-type stars. A particularly detailed picture of the innermost shells around AGB stars is provided by SiO…

We report the detection of OH satellite line masers at 1720 MHz and 1612 MHz from the nuclear region of the starburst galaxy M82. The observations were aimed at detecting 1720 MHz maser emission from the known radio emitting SNR in the…

(abridged) The role of magnetic field in the shaping of Planetary Nebulae (PNe), either directly or indirectly after being enhanced by binary interaction, has long been a topic of debate. Large scale magnetic fields around pre-PNe have been…