Minimal HCN emission from molecular clouds in M33

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 星系中的恒星形成研究团组

	Minimal HCN emission from molecular clouds in M33
	Rosolowsky, Erik 1; Pineda, Jaime E.2,3; Gao, Yu4
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2011-08-01
卷号	415 期号:2 页码:1977-1984
关键词	stars: formation ISM: clouds galaxies: individual: M33 radio lines: ISM
ISSN号	0035-8711
英文摘要	Since HCN emission has been shown to be a linear tracer of ongoing star formation activity, we have searched for HCN (J = 1 -> 0) emission from known GMCs in the nearby galaxy M33. No significant HCN emission has been found along any of the lines of sight. We find two lines of sight with CO-to-HCN integrated intensity ratios up to 280, nearly a factor of 6 above what is found in comparable regions of the Milky Way. Star formation tracers suggest that the HCN-to-star formation rate ratio (L-HCN/(M) over dot(star)) is a factor of 6 lower than what is observed in the Milky Way (on average) and local extragalactic systems. Simple chemical models accounting for the subsolar N/O ratio suggest that depletion cannot account for the high CO-to-HCN ratios. Given HCN formation requires high extinction (A(V) > 4), low metallicity may yield reduced dust shielding and thus a high CO/HCN ratio. The turbulence and structure of GMCs in M33 are comparable to those found in other systems, so the differences are unlikely to result from different GMC properties. Since lower CO-to-HCN ratios are associated with the highest rates of star formation, we attribute the deficits in part to evolutionary effects within GMCs.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	STAR-FORMING GALAXIES ; DENSE GAS ; FORMATION LAW ; SCHMIDT LAW ; CO ; GRADIENT ; TRACERS ; REGIONS ; COMPLEX ; CORES
收录类别	SCI
语种	英语
WOS记录号	WOS:000293756300080
公开日期	2012-08-07
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/4523]
专题	紫金山天文台_星系中的恒星形成研究团组
作者单位	1.Univ British Columbia Okanagan, Kelowna, BC V1V 1V7, Canada 2.Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA 3.Univ Manchester, Sch Phys & Astron, Jodrell Bank Ctr Astrophys, Manchester M13 9PL, Lancs, England 4.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China
推荐引用方式 GB/T 7714	Rosolowsky, Erik,Pineda, Jaime E.,Gao, Yu. Minimal HCN emission from molecular clouds in M33[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2011,415(2):1977-1984.
APA	Rosolowsky, Erik,Pineda, Jaime E.,&Gao, Yu.(2011).Minimal HCN emission from molecular clouds in M33.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,415(2),1977-1984.
MLA	Rosolowsky, Erik,et al."Minimal HCN emission from molecular clouds in M33".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 415.2(2011):1977-1984.