WHAT DRIVES THE EXPANSION OF GIANT H II REGIONS?: A STUDY OF STELLAR FEEDBACK IN 30 DORADUS

Journal Article · Wed Apr 20 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/731/2/91· OSTI ID:21574724

Lopez, Laura A; Krumholz, Mark R; Prochaska, J Xavier; Ramirez-Ruiz, Enrico ^[1]

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1. Department of Astronomy and Astrophysics, University of California Santa Cruz, 159 Interdisciplinary Sciences Building, 1156 High Street, Santa Cruz, CA 95064 (United States)

Observations show that star formation is an inefficient and slow process. This result can be attributed to the injection of energy and momentum by stars that prevents free-fall collapse of molecular clouds. The mechanism of this stellar feedback is debated theoretically; possible sources of pressure include the classical warm H II gas, the hot gas generated by shock heating from stellar winds and supernovae, direct radiation of stars, and the dust-processed radiation field trapped inside the H II shell. In this paper, we measure observationally the pressures associated with each component listed above across the giant H II region 30 Doradus in the Large Magellanic Cloud. We exploit high-resolution, multi-wavelength images (radio, infrared, optical, ultraviolet, and X-ray) to map these pressures as a function of position. We find that radiation pressure dominates within 75 pc of the central star cluster, R136, while the H II gas pressure dominates at larger radii. By contrast, the dust-processed radiation pressure and hot gas pressure are generally weak and not dynamically important, although the hot gas pressure may have played a more significant role at early times. Based on the low X-ray gas pressures, we demonstrate that the hot gas is only partially confined and must be leaking out the H II shell. Additionally, we consider the implications of a dominant radiation pressure on the early dynamics of 30 Doradus.

• OSTI ID: 21574724
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 731; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BINARY STARS
ERUPTIVE VARIABLE STARS
EVOLUTION
FEEDBACK
GALAXIES
HEATING
MAGELLANIC CLOUDS
PLASMA HEATING
RADIATION PRESSURE
SHOCK HEATING
STAR CLUSTERS
STAR EVOLUTION
STARS
STELLAR ACTIVITY
STELLAR WINDS
SUPERNOVAE
VARIABLE STARS