Related papers: Parsec-scale magnetic fields in Arp 220
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…
With the recent advent of circular polarization capabilities at the Atacama Large Millimeter/submillimeter Array (ALMA), Zeeman effect measurements of spectral lines are now possible as a means to directly probe line-of-sight magnetic…
Recent high resolution near infrared (HST-NICMOS) and mm-interferometric imaging have revealed dense gas and dust accretion disks in nearby ultra-luminous galactic nuclei. In the best studied ultraluminous IR galaxy, Arp 220, the 2 micron…
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…
The relationship between galaxies and their supermassive black holes (SMBHs) is an area of active research. One way to investigate this is to compare parsec-scale jets formed by SMBHs with the projected shape of their kiloparsec-scale host…
Measurement of magnetic fields in dense molecular clouds is essential for understanding the fragmentation process prior to star formation. Radio interferometric observations of CCS 22.3 GHz emission, from the starless core TMC-1C, have been…
Aims: We have observed the 6030 and 6035 MHz transitions of OH in high-mass star-forming regions to obtain magnetic field estimates in both maser emission and absorption. Methods: Observations were taken with the Effelsberg 100 m telescope.…
Magnetism is one of the most important forces on the interstellar medium (ISM), anisotropically regulating the structure and star formation that drive galactic evolution. Recent high dynamic range observations of diffuse gas and molecular…
Our knowledge of the presence and the strength of magnetic fields in intermediate-mass pre-main-sequence stars remains very poor. We present new magnetic field measurements in six Herbig Ae/Be stars observed with HARPS in…
It is believed that dual active galactic nuclei (dual AGN) will form during galaxies merge. Studying dual-AGN emission can provide valuable insights into galaxy merging and evolution. To investigate parsec-scale radio emission properties,…
We have used the rocket-borne Wide-Field Imaging Survey Polarimeter (WISP) to image a 1.5 deg. by 4.8 deg. area of the western side of the LMC at a wavelength of 215 nm and a resolution of 1' x 1.5'. These are the first wide-field…
In this paper we use electrically detected optical excitation spectroscopy of individual erbium ions in silicon to determine their optical and paramagnetic properties simultaneously. We demonstrate that this high spectral resolution…
We report the first detection of circular polarization in 4.7 GHz excited OH masers in star-forming regions made using full Stokes measurements with the Green Bank 100m telescope. The Zeeman shift between the two circular components…
We present results of simultaneous dual-frequency (2 GHz and 8 GHz) very long baseline interferometry (VLBI) observations of 12 active galactic nuclei with prominent jets. Spectral properties of the jets and evolution of their brightness…
We present circular polarization measurements of circumstellar H_2O masers. The circular polarization detected in the (6_{16}-5_{23}) rotational transition of the H_{2}O maser can be attributed to Zeeman splitting in the intermediate…
We present the final results from the Arecibo Observatory OH megamaser survey. We discuss in detail the properties of the remaining 18 OH megamasers detected in the survey, including 3 redetections. We place upper limits on the OH emission…
The Zeeman effect and dust grain alignment are two major methods for probing magnetic fields (B-fields) in molecular clouds, largely motivated by the study of star formation, as the B-field may regulate gravitational contraction and channel…
This thesis reports on the application of new wide-field Very Long Baseline Interferometry (VLBI) imaging techniques using real data for the first time. These techniques are used to target three specific science areas: (i) a…
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…
We report dual-frequency very long baseline interferometry (VLBI) observations at 22 and 43 GHz toward the nucleus of a nearby radio galaxy NGC 4261. In particular, we present a VLBI image of the 22 GHz H2O maser line and its location in…