Strong magnetic field in W75N OH maser flare
نویسنده
چکیده
A flare of OH maser emission was discovered in W75N in 2000. Its location was determined with the VLBA to be within 110 au from one of the ultra-compact H II regions, VLA2. The flare consisted of several maser spots. Four of the spots were found to form Zeeman pairs, all of them with a magnetic field strength of about 40 mG. This is the highest ever magnetic field strength found in OH masers , an order of magnitude higher than in typical OH masers. Three possible sources for the enhanced magnetic field are discussed: (a) the magnetic field of the exciting star dragged out by the stellar wind; (b) the general interstellar field in the gas compressed by the MHD shock; and (c) the magnetic field of planets which orbit the exciting star and produce maser emission in gaseous envelopes.
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