Specific Star Forming Regions -- Poster Presentation

Investigation of Diffuse X-ray Emission in the Massive Star Forming Region NGC 6334 with Chandra and Future Prospects with Astro-E2

Yuichiro Ezoe, ISAS/JAXA

Motohide Kokubun (University of Tokyo), Kazuo Makishima (University of Tokyo)


Recent studies with Chandra have been revealing that there are various diffuse X-ray emission originated from 10$^{6-7}$ K plasma or possible accelerated particles in massive star forming regions (e.g., Wolk et al. 2002, Townsley et al. 2003). We analyzed Chandra data of the representative massive star-forming region NGC 6334 where hard X-ray emission have been detected with ASCA (Sekimoto et al. 2000). In addition to 800 point sources, we found diffuse X-ray emission (5x9 pc and 2e33 erg/s in the 0.5-8 keV luminosity). It shows positionally different spectra; thermal plasma emission of several keV in low absorption regions, while flat continua in dense cloud cores. The former emission can be explained by hot plasma heated at strong shocks of fast stellar-winds from young OB stars, while the latter by accelerated particles at the shock. We then roughly estimated possible contribution of diffuse X-ray emission in Galactic massive star forming regions to the puzzling Galactic Ridge X-ray emission (e.g., Kaneda et al. 1997) as $\sim10$\% in luminosity. Related to this issue, we show potential importance of simultaneous observation with Chandra and, the Japanese new X-ray observatory, Astro-E2.