CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Linear Polarization of Class I Methanol Masers in Massive Star-forming Regions

Ji-hyun Kang ; Do-Young Byun ; Kee-Tae Kim ; Jongsoo Kim ; A.-Ran Lio ; Wouter Vlemmings (Institutionen för rymd- och geovetenskap, Radioastronomi och astrofysik)
Astrophysical Journal Supplement Series (0067-0049). Vol. 227 (2016), 2,
[Artikel, refereegranskad vetenskaplig]

Class I methanol masers are found to be good tracers of the interaction between outflows from massive young stellar objects with their surrounding media. Although polarization observations of Class II methanol masers have been able to provide information about magnetic fields close to the central (proto)stars, polarization observations of Class I methanol masers are rare, especially at 44 and 95 GHz. We present the results of linear polarization observations of 39 Class I methanol maser sources at 44 and 95 GHz. These two lines are observed simultaneously with one of the 21 m Korean VLBI Network telescopes in single-dish mode. Approximately 60% of the observed sources have fractional polarizations of a few percent in at least one transition. This is the first reported detection of linear polarization of the 44 GHz methanol maser. The two maser transitions show similar polarization properties, indicating that they trace similar magnetic environments, although the fraction of the linear polarization is slightly higher at 95 GHz. We discuss the association between the directions of polarization angles and outflows. We also discuss some targets having different polarization properties at both lines, including DR21(OH) and G82.58+0.20, which show the 90° polarization angle flip at 44 GHz.

Nyckelord: ISM: magnetic fields, masers, polarization, stars: massive, stars: protostars, surveys



Denna post skapades 2016-12-19. Senast ändrad 2017-01-17.
CPL Pubid: 246349

 

Läs direkt!

Lokal fulltext (fritt tillgänglig)

Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för rymd- och geovetenskap, Radioastronomi och astrofysik (2010-2017)

Ämnesområden

Astronomi
Stjärnors bildning och utveckling

Chalmers infrastruktur

Onsala rymdobservatorium

 


Projekt

Denna publikation är ett resultat av följande projekt:


Magnetic fields and the outflows during the formation and evolution of stars (OUTFLOWMAGN) (EC/FP7/614264)