CLASS I METHANOL MASER CONDITIONS NEAR SNRS

McEwen, Bridget C.

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https://hdl.handle.net/2142/79419 Copy

Description

Title

CLASS I METHANOL MASER CONDITIONS NEAR SNRS

Author(s)

McEwen, Bridget C.

Contributor(s)

• Sjouwerman, Lorﾇnt O.
• Pihlstrﾚm, Ylva M.

Issue Date

25-Jun-15

Keyword(s)

Astronomy

Abstract

We present results from calculations of the physical conditions necessary for the occurrence of 36.169 ($4_{-1}-3_{0}, E$), 44.070 ($7_{0}-6_{1},A^+$), 84.521 ($5_{-1}-4_{0},E$), and 95.169 ($8_{0}-7_{1},A^+$) GHz methanol (CH$_3$OH) maser emission lines near supernova remnants (SNRs), using the MOLPOP-CEP program. The calculations show that given a sufficient methanol abundance, methanol maser emission arises over a wide range of densities and temperatures, with optimal conditions at $nsim 10^4-10^6$ cm$^{-3}$ and $T>60$ K. The 36~GHz and 44~GHz transitions display more significant maser optical depths compared to the 84~GHz and 95~GHz transitions over the majority of physical conditions. It is also shown that line ratios are an important and applicable probe of the gas conditions. The line ratio changes are largely a result of the $E$-type transitions becoming quenched faster at increasing densities. The modeling results will be discussed using recent observations of CH$_3$OH masers near the SNRs G1.4$-$0.1, W28, and Sgr,A,East and used as a diagnostic tool to estimate densities and temperatures of the regions in which the CH$_3$OH masers are observed.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/79419

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