Collisional excitation of OH(6049 MHz) masers in supernova remnant - Molecular cloud interactions

Mark Wardle

doi:10.1017/S1743921307013300

Collisional excitation of OH(6049 MHz) masers in supernova remnant - Molecular cloud interactions

Mark Wardle^*

^*Corresponding author for this work

Research output: Contribution to journal › Article

2 Citations (Scopus)

Abstract

OH (1720 MHz) masers serve as indicators of SNR - molecular cloud interaction sites. These masers are collisionally excited in warm (50-100 K) shocked gas with densities of order 10⁵cm³ when the OH column density is in the range 10¹⁶10¹⁷cm². Here I present excitation calculations which show that when the OH column density exceeds 10¹⁷cm² at similar densities and temperatures, the inversion of the 1720 MHz line switches off and instead the 6049 MHz transition in the first excited rotational state of OH becomes inverted. This line may serve as a complementary signal of warm, shocked gas when the OH column density is large.

Original language	English
Pages (from-to)	336-337
Number of pages	2
Journal	Proceedings of the International Astronomical Union
Volume	3
Issue number	S242
DOIs	https://doi.org/10.1017/S1743921307013300
Publication status	Published - Mar 2007

Keywords

Molecular processes
Radiation mechanisms: nonthermal
Radio lines: ISM
Supernova remnants

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10.1017/S1743921307013300

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title = "Collisional excitation of OH(6049 MHz) masers in supernova remnant - Molecular cloud interactions",

abstract = "OH (1720 MHz) masers serve as indicators of SNR - molecular cloud interaction sites. These masers are collisionally excited in warm (50-100 K) shocked gas with densities of order 105cm3 when the OH column density is in the range 10161017cm2. Here I present excitation calculations which show that when the OH column density exceeds 1017cm2 at similar densities and temperatures, the inversion of the 1720 MHz line switches off and instead the 6049 MHz transition in the first excited rotational state of OH becomes inverted. This line may serve as a complementary signal of warm, shocked gas when the OH column density is large.",

keywords = "Molecular processes, Radiation mechanisms: nonthermal, Radio lines: ISM, Supernova remnants",

author = "Mark Wardle",

year = "2007",

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doi = "10.1017/S1743921307013300",

language = "English",

volume = "3",

pages = "336--337",

journal = "Proceedings of the International Astronomical Union",

issn = "1743-9213",

publisher = "Cambridge University Press (CUP)",

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T1 - Collisional excitation of OH(6049 MHz) masers in supernova remnant - Molecular cloud interactions

AU - Wardle, Mark

PY - 2007/3

Y1 - 2007/3

N2 - OH (1720 MHz) masers serve as indicators of SNR - molecular cloud interaction sites. These masers are collisionally excited in warm (50-100 K) shocked gas with densities of order 105cm3 when the OH column density is in the range 10161017cm2. Here I present excitation calculations which show that when the OH column density exceeds 1017cm2 at similar densities and temperatures, the inversion of the 1720 MHz line switches off and instead the 6049 MHz transition in the first excited rotational state of OH becomes inverted. This line may serve as a complementary signal of warm, shocked gas when the OH column density is large.

AB - OH (1720 MHz) masers serve as indicators of SNR - molecular cloud interaction sites. These masers are collisionally excited in warm (50-100 K) shocked gas with densities of order 105cm3 when the OH column density is in the range 10161017cm2. Here I present excitation calculations which show that when the OH column density exceeds 1017cm2 at similar densities and temperatures, the inversion of the 1720 MHz line switches off and instead the 6049 MHz transition in the first excited rotational state of OH becomes inverted. This line may serve as a complementary signal of warm, shocked gas when the OH column density is large.

KW - Molecular processes

KW - Radiation mechanisms: nonthermal

KW - Radio lines: ISM

KW - Supernova remnants

UR - http://www.scopus.com/inward/record.url?scp=38849174765&partnerID=8YFLogxK

U2 - 10.1017/S1743921307013300

DO - 10.1017/S1743921307013300

M3 - Article

AN - SCOPUS:38849174765

SN - 1743-9213

VL - 3

SP - 336

EP - 337

JO - Proceedings of the International Astronomical Union

JF - Proceedings of the International Astronomical Union

IS - S242

ER -

Collisional excitation of OH(6049 MHz) masers in supernova remnant - Molecular cloud interactions

Abstract

Keywords

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