A Near‐Infrared and X‐Ray Study of W49 B: A Wind Cavity Explosion
Autor: | Jonathan W. Keohane, William T. Reach, Jeonghee Rho, Thomas H. Jarrett |
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Rok vydání: | 2007 |
Předmět: |
Physics
Jet (fluid) Astrophysics::High Energy Astrophysical Phenomena Molecular cloud Astrophysics (astro-ph) Near-infrared spectroscopy Interstellar cloud FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics law.invention Telescope Supernova Stars Space and Planetary Science law Astrophysics::Solar and Stellar Astrophysics Supernova remnant Caltech Library Services Astrophysics::Galaxy Astrophysics |
Zdroj: | The Astrophysical Journal. 654:938-944 |
ISSN: | 1538-4357 0004-637X |
Popis: | We present near-infrared narrow-band images of the supernova remnant W49B, taken with the WIRC instrument on the Hale 200 inch telescope on Mt. Palomar. The 1.64 micron [Fe II] image reveals a barrel-shaped structure with coaxial rings, which is suggestive of bipolar wind structures surrounding massive stars. The 2.12 micron shocked molecular hydrogen image extends 1.9 pc outside of the [Fe II] emission to the southeast. We also present archival Chandra data, which show an X-ray jet-like structure along the axis of the [Fe II] barrel, and flaring at each end. Fitting single temperature X-ray emission models reveals: an enhancement of heavy elements, with particularly high abundances of hot Fe and Ni, and relatively metal-rich core and jet regions. We interpret these findings as evidence that W49B originated inside a wind-blown bubble (R ~ 5 pc) interior to a dense molecular cloud. This suggests that W49B's progenitor was a supermassive star, that could significantly shape its surrounding environment. We also suggest two interpretations for the jet morphology, abundance variations and molecular hydrogen emission: (1) the explosion may have been jet-driven and interacting with the molecular cavity (i.e. a Gamma-ray burst); or (2) the explosion could have been a traditional supernova, with the jet structure being the result of interactions between the shock and an enriched interstellar cloud. Comment: 9 pages with embedded figures Accepted by the Astrophysical Journal |
Databáze: | OpenAIRE |
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