AN INFRARED THROUGH RADIO STUDY OF THE PROPERTIES AND EVOLUTION OF IRDC CLUMPS

被引:77
作者
Battersby, Cara [1 ,2 ]
Bally, John [1 ]
Jackson, James M. [2 ]
Ginsburg, Adam [1 ]
Shirley, Yancy L. [3 ]
Schlingman, Wayne [3 ]
Glenn, Jason [1 ]
机构
[1] Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA
[2] Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA
[3] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA
基金
美国国家科学基金会;
关键词
dust; extinction; ISM: clouds; stars: formation; stars: pre-main sequence; MASSIVE STAR-FORMATION; YOUNG STELLAR OBJECT; DARK CLOUDS; GALACTIC PLANE; PHYSICAL-PROPERTIES; MOLECULAR CLOUDS; INNER GALAXY; MILKY-WAY; MU-M; CORES;
D O I
10.1088/0004-637X/721/1/222
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We examine the physical properties and evolutionary stages of a sample of 17 clumps within 8 Infrared Dark Clouds (IRDCs) by combining existing infrared, millimeter, and radio data with new Bolocam Galactic Plane Survey (BGPS) 1.1 mm data, Very Large Array radio continuum data, and Heinrich Hertz Telescope dense gas (HCO(+) and N(2)H(+)) spectroscopic data. We combine literature studies of star formation tracers and dust temperatures within IRDCs with our search for ultracompact (UC) H II regions to discuss a possible evolutionary sequence for IRDC clumps. In addition, we perform an analysis of mass tracers in IRDCs and find that 8 mu m extinction masses and 1.1 mm BGPS masses are complementary mass tracers in IRDCs except for the most active clumps (notably those containing UC H II regions), for which both mass tracers suffer biases. We find that the measured virial masses in IRDC clumps are uniformly higher than the measured dust continuum masses on the scale of similar to 1 pc. We use (13)CO, HCO(+), and N(2)H(+) to study the molecular gas properties of IRDCs and do not see any evidence of chemical differentiation between hot and cold clumps on the scale of similar to 1 pc. However, both HCO(+) and N(2)H(+) are brighter in active clumps, due to an increase in temperature and/or density. We report the identification of four UC H II regions embedded within IRDC clumps and find that UC H II regions are associated with bright (greater than or similar to 1 Jy) 24 mu m point sources, and that the brightest UC H II regions are associated with "diffuse red clumps" (an extended enhancement at 8 mu m). The broad stages of the discussed evolutionary sequence (from a quiescent clump to an embedded H II region) are supported by literature dust temperature estimates; however, no sequential nature can be inferred between the individual star formation tracers.
引用
收藏
页码:222 / 250
页数:29
相关论文
共 56 条
  • [51] NH3 observations of the infrared dark cloud G28.34+0.06
    Wang, Y.
    Zhang, Q.
    Pillai, T.
    Wyrowski, F.
    Wu, Y.
    [J]. ASTROPHYSICAL JOURNAL LETTERS, 2008, 672 (01): : L33 - L36
  • [52] New catalogs of compact radio sources in the Galactic plane
    White, RL
    Becker, RH
    Helfand, DJ
    [J]. ASTRONOMICAL JOURNAL, 2005, 130 (02) : 586 - 596
  • [53] THE MORPHOLOGIES AND PHYSICAL-PROPERTIES OF ULTRACOMPACT H-II REGIONS
    WOOD, DOS
    CHURCHWELL, E
    [J]. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1989, 69 (04) : 831 - 895
  • [54] WYROWSKI F, 2000, BAAS, V197, P515
  • [55] FRAGMENTATION AT THE EARLIEST PHASE OF MASSIVE STAR FORMATION
    Zhang, Qizhou
    Wang, Yang
    Pillai, Thushara
    Rathborne, Jill
    [J]. ASTROPHYSICAL JOURNAL, 2009, 696 (01) : 268 - 273
  • [56] Toward understanding massive star formation
    Zinnecker, Hans
    Yorke, Harold W.
    [J]. ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, 2007, 45 : 481 - 563