2005/10/26 by Yuichiro Ezoe, M. Kokubun, Motohide Kokubun +4 · 1 citation
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/499120
published as Astrophys.J.638:860-877,2006 · 43 pages, 14 figures, accepted for publication in ApJ, A full resolution ot the paper can be found at http://www.astro.isas.jaxa.jp/~ezoe/ngc6334/yezoe2005apj_chandra_ngc6334.pdf
arxiv created 2005/10/26 · openalex publication_date 2006/02/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Chandra ACIS-I data of the molecular cloud and H II region complex NGC 6334 were analyzed. The hard X-ray clumps detected with ASCA (Sekimoto and coworkers) were resolved into 792 point sources. After removing the point sources, an extended X-ray emission component was detected over a 5 × 9 pc 2 region, with the 0.5-8 keV absorption-corrected luminosity of 2 × 10 33 ergs s -1 . The contribution from faint point sources to this extended emission was estimated as at most ~20%, suggesting that most of the emission is diffuse in nature. The X-ray spectrum of the diffuse emission was observed to vary from place to place. In tenuous molecular cloud regions with hydrogen column density of (0.5-1) × 10 22 cm -2 , the spectrum can be represented by a thermal plasma model with temperatures of several keV. The spectrum in dense cloud cores exhibits harder continuum, together with higher absorption of more than ~3 × 10 22 cm -2 . In some of such highly obscured regions, the spectra show extremely hard continua equivalent to a photon index of ~1, and favor a nonthermal interpretation. These results are discussed in the context of thermal and nonthermal emission, both powered by fast stellar winds from embedded young early-type stars through shock transitions.