Parsec-scale X-ray Flows in High-mass Star-forming Regions

Proceedings of the International Astronomical Union 06/2005; DOI: 10.1017/S1743921305004667
Source: arXiv

ABSTRACT The Chandra X-ray Observatory is providing remarkable new views of massive star-forming regions, revealing all stages in the life cycle of high-mass stars and their effects on their surroundings. We present a Chandra tour of several high-mass star-forming regions, highlighting physical processes that characterize the life of a cluster of high-mass stars, from deeply-embedded cores too young to have established an HII region to superbubbles so large that they shape our views of galaxies. Along the way we see that X-ray observations reveal hundreds of stellar sources powering great HII region complexes, suffused by both hard and soft diffuse X-ray structures caused by fast O-star winds thermalized in wind-wind collisions or by termination shocks against the surrounding media. Finally, we examine the effects of the deaths of high-mass stars that remained close to their birthplaces, exploding as supernovae within the superbubbles that these clusters created. We present new X-ray results on W51 IRS2E and 30 Doradus and we introduce new data on Trumpler 14 in Carina and the W3 HII region complexes W3 Main and W3(OH). Comment: 6 pages, 3 figures, to appear in the proceedings of IAU Symposium 227,"Massive Star Birth - A Crossroads of Astrophysics," eds. R. Cesaroni, E. Churchwell, M. Felli, and C.M. Walmsley

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    ABSTRACT: Stellar clusters are potential acceleration sites of very-high-energy (VHE, E > 100GeV) particles since they host supernova remnants (SNRs) and pulsar wind nebulae (PWNe). Additionally, in stellar clusters, particles can also be accelerated e.g. at the boundaries of wind-blown bubbles, in colliding wind zones in massive binary systems or in the framework of collective wind or wind/supernova(SN) ejecta scenarios. Motivated by the detection of VHE gamma-ray emission towards Westerlund 2 and assuming similar particle acceleration mechanisms at work, Westerlund 1 is an even more promising target for VHE gamma-ray observations given that massive star content and distance are more favorable for detectable VHE gamma-ray emission compared to Westerlund 2. Here, H.E.S.S. observations of massive stellar clusters in general with special emphasis on the most massive stellar cluster in the galaxy, Westerlund 1 are summarized. Comment: Invited talk at HEPIMS Workshop (Jaen 2009); 10 pages, 4 figures, to appear in PASP
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    ABSTRACT: We present an X-ray tour of diffuse emission in the 30 Doradus star-forming complex in the Large Magellanic Cloud using high spatial resolution X-ray images and spatially resolved spectra obtained with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. The dominant X-ray feature of the 30 Doradus nebula is the intricate network of diffuse emission generated by interacting stellar winds and supernovae working together to create vast superbubbles filled with hot plasma. We construct maps of the region showing variations in plasma temperature (T = 3-9 million degrees), absorption [NH = (1-6) × 1021 cm-2], and absorption-corrected X-ray surface brightness [SX = (3-126) × 1031 ergs s-1 pc-2]. Enhanced images reveal the pulsar wind nebula in the composite supernova remnant N157B, and the Chandra data show spectral evolution from nonthermal synchrotron emission in the N157B core to a thermal plasma in its outer regions. In a companion paper we show that R136, the central massive star cluster, is resolved at the arcsecond level into almost 100 X-ray sources. Through X-ray studies of 30 Doradus the complete life cycle of such a massive stellar cluster can be revealed.
    The Astronomical Journal 12/2007; 131(4):2140. · 4.97 Impact Factor
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    ABSTRACT: We report here results from a Chandra ACIS observation of the stellar populations in and around the M17 H II region. The field reveals 886 sources with observed X-ray luminosities (uncorrected for absorption) between ~ 29.3 ergs s-1 < log LX < 32.8 ergs s-1, 771 of which have stellar counterparts in infrared images. In addition to comprehensive tables of X-ray source properties, several results are presented:
    The Astrophysical Journal Supplement Series 12/2008; 169(2):353. · 16.24 Impact Factor

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