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Related papers: Magnetic Field Structure of Orion Source I

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We present the first images of the 28SiO v=1, J=2-1 maser emission around the closest known massive young stellar object Orion Source I observed at 86 GHz (3mm) with the VLBA. These images have high spatial (~0.3 mas) and spectral (~0.054…

Astrophysics of Galaxies · Physics 2017-10-25 S. Issaoun , C. Goddi , L. D. Matthews , L. J. Greenhill , M. D. Gray , E. M. L. Humphreys , C. J. Chandler , M. Krumholz , H. Falcke

Three deep radio continuum surveys of the Andromeda galaxy, M 31, were performed at 11.3, 6.2, and 3.6 cm wavelength with the Effelsberg 100-m telescope. At all wavelengths, the total and polarized emission is concentrated in a ring-like…

Astrophysics of Galaxies · Physics 2019-12-25 R. Beck , E. M. Berkhuijsen , R. Gießübel , D. D. Mulcahy

The canonical theory of star formation in a magnetized environment predicts the formation of hourglass-shaped magnetic fields during the prestellar collapse phase. In protostellar cores, recent observations reveal complex and strongly…

Solar and Stellar Astrophysics · Physics 2022-09-07 Gianfranco Bino , Shantanu Basu , Masahiro N Machida , Aris Tritsis , Mahmoud Sharkawi , Kundan Kadam , Indrani Das

We present the first circular polarization measurements of circumstellar H2O masers. Previously the magnetic field in circumstellar envelopes has been estimated using polarization observations of SiO and OH masers. SiO masers are probes of…

Astrophysics · Physics 2009-11-06 W. Vlemmings , P. J. Diamond , H. J. van Langevelde

We present a study of the line-of-sight magnetic fields in five large-diameter Galactic HII regions. Using the Faraday rotation of background polarized radio sources, as well as dust-corrected H-alpha surface brightness as a probe of…

Astrophysics of Galaxies · Physics 2015-05-28 Lisa Harvey-Smith , Gregory J. Madsen , Bryan M. Gaensler

We present ALMA observations of SiO, SiS, H$_2$O , NaCl, and SO line emission at ~30 to 50 mas resolution. These images map the molecular outflow and disk of Orion Source I (SrcI) on ~12 to 20 AU scales. Our observations show that the flow…

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.…

Astrophysics · Physics 2007-05-23 Fabrice Herpin , Alain Baudry , Clemens Thum , Dave Morris , Helmut Wiesemeyer

The forthcoming new-generation radio telescope SKA (Square Kilometre Array) and its precursors will provide a rapidly growing number of polarized radio sources. Our analysis aims on what can be learned from these sources concerning the…

Astrophysics · Physics 2009-11-13 Rodion Stepanov , Tigran G. Arshakian , Rainer Beck , Peter Frick , Marita Krause

We present CO(2-1), $^{13}$CO(2-1), CO(6-5), CO(7-6), and SO(6$_5-5_4$) line observations made with the {\it IRAM 30 m} and {\it APEX} radiotelescopes and the {\it Submillimeter Array} toward the highly collimated and extended southwest…

Astrophysics of Galaxies · Physics 2015-05-13 Luis A. Zapata , Johannes Schmid-Burgk , Dirk Muders , Peter Schilke , Karl Menten , Rolf Guesten

The Class 0 protostar IRAS 16293$-$2422 Source A is known to be a binary system (A1 and A2) or even a multiple system, which processes a complex outflow structure. We have observed this source in the C$^{34}$S, SO, and OCS lines at 3.1 mm…

The {\em B}-field Orion Protostellar Survey (BOPS) recently obtained polarimetric observations at 870 ${\rm \mu m}$ towards 61 protostars in the Orion molecular clouds with $\sim 1^{\prime\prime}$ spatial resolution using the Atacama Large…

Faraday rotation of radio source polarization provides a measure of the integrated magnetic field along the observational lines of sight. We compare a new, large sample of Faraday rotation measures (RMs) of polarized extragalactic sources…

Astrophysics · Physics 2009-11-13 Yongzhong Xu , Philipp P. Kronberg , Salman Habib , Quentin W. Dufton

The goal of this work is to constrain the strength and structure of the magnetic field associated with the environment of the radio source 3C 449, using observations of Faraday rotation, which we model with a structure function technique…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 D. Guidetti , R. A. Laing , M. Murgia , F. Govoni , L. Gregorini , P. Parma

Using the linearly polarized intensity and polarization angle data at 3.6, 6.2 and 20 cm, we determine variations of Faraday rotation and depolarization across the nearby galaxy M33. A 3-D model of the regular magnetic field is fitted to…

Astrophysics · Physics 2009-11-13 F. S. Tabatabaei , M. Krause , A. Fletcher , R. Beck

We present multi-epoch VLBA imaging of the 28SiO v=1 & v=2, J=1-0 maser emission toward the massive YSO Orion Source I. Both SiO transitions were observed simultaneously with an angular resolution of ~0.5 mas (~0.2 AU for d=414 pc). Here we…

Solar and Stellar Astrophysics · Physics 2014-11-20 L. D. Matthews , L. J. Greenhill , C. Goddi , C. J. Chandler , E. M. L. Humphreys , M. Kunz

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…

Astrophysics · Physics 2009-11-07 W. H. T. Vlemmings , P. J. Diamond , H. J. van Langevelde

Total magnetic fields in spiral galaxies, as observed through their total synchrotron emission, are strongest (up to \simeq 30\mu G) in the spiral arms. The degree of radio polarization is low; the field in the arms must be mostly turbulent…

Astrophysics · Physics 2009-11-11 Rainer Beck

The configuration of the regular magnetic field in M31 is deduced from radio polarization observations at the wavelengths 6, 11 and 20 cm. By fitting the observed azimuthal distribution of polarization angles, we find that the regular…

Astrophysics · Physics 2009-11-10 A. Fletcher , E. M. Berkhuijsen , R. Beck , A. Shukurov

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…

Astrophysics · Physics 2009-11-10 W. H. T. Vlemmings , H. J. van Langevelde , P. J. Diamond

We present Submillimeter Array (SMA) polarization observations of the CO $J$ = 3--2 line toward the NGC1333 IRAS 4A. The CO Stokes $I$ maps at an angular resolution of $\sim$1$\arcsec$ reveal two bipolar outflows from the binary sources of…

Solar and Stellar Astrophysics · Physics 2016-03-23 Tao-Chung Ching , Shih-Ping Lai , Qizhou Zhang , Louis Yang , Josep M. Girart , Ramprasad Rao