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Statistics of the 6.7 GHz methanol maser variability from the Toruń survey

Published online by Cambridge University Press:  03 August 2017

Anna Niezurawska ,
Marian Szymczak ,
Grzegorz Hrynek  and
Andrzej J. Kus
Anna Niezurawska
Affiliation:
Toruń Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, PL-87100 Toruń, Poland
Marian Szymczak
Affiliation:
Toruń Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, PL-87100 Toruń, Poland
Grzegorz Hrynek
Affiliation:
Toruń Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, PL-87100 Toruń, Poland
Andrzej J. Kus
Affiliation:
Toruń Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, PL-87100 Toruń, Poland

Abstract

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A sample of 174 methanol sources has been observed with the 32 m Toruń radio telescope at four or five epochs separated by 3-7 months. Observations of the 6.7 GHz maser line revealed that about 80% of sources are variable. 20% of sources showed strong variations of the integrated flux density usually on time-scales of 5-12 months. These variations were associated with strong changes in the relative intensities of maser features. Methanol emission from five sources disappeared. The time-scales of variability were longer than 12 months for only 23% of variable sources. It is suggested that the variability of methanol emission is related to the dynamics of the maser regions.

Type
Part 1. Star Formation
Information
Symposium - International Astronomical Union , Volume 206: Cosmic Masers: From Protostars to Blackholes , 2002 , pp. 135 - 138
Copyright
Copyright © Astronomical Society of the Pacific 2002 

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