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A near-infrared and X-ray study of W49B: A wind cavity explosion

Keohane, Jonathan W. and Reach, William T. and Rho, Jeonghee and Jarrett, Thomas H. (2007) A near-infrared and X-ray study of W49B: A wind cavity explosion. Astrophysical Journal, 654 (2). pp. 938-944. ISSN 0004-637X.

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We present near-infrared narrowband images of the supernova remnant W49 B, taken with the WIRC instrument on the Hale 200 inch (5 m) telescope on Mount Palomar. The 1.64 μm [Fe II] image reveals a barrel-shaped structure with coaxial rings, which is suggestive of bipolar wind structures surrounding massive stars. The 2.12 μm 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 jetlike structure along the axis of the [Fe II] barrel, 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 W49 B originated inside a wind-blown bubble (R ∼ 5 pc) inside a dense molecular cloud. This suggests that W49 B'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, 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.

Item Type:Article
Related URLs:
URLURL TypeDescription
Reach, William T.0000-0001-8362-4094
Rho, Jeonghee0000-0003-3643-839X
Jarrett, Thomas H.0000-0002-4939-734X
Additional Information:© 2007 The American Astronomical Society. Received 2004 July 20; accepted 2006 September 1. We are grateful to L. Rudnick, who participated in the observing run and contributed significant insight. We are grateful to J. Hester, T. Pannuti, and W. Tucker for insightful discussions. We also thank R. Petre for discussions on W49 B prior to this work. Support for this work was provided by NASA through LTSA grant NRA-01-01-LTSA-013 and Chandra award GO3-4070C awarded to J. Rho.
Subject Keywords:circumstellar matter—gamma rays: bursts—infrared: ISM—supernova remnants—supernovae: individual (W49 B)—X-rays: ISM
Issue or Number:2
Record Number:CaltechAUTHORS:KEOapj07
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7779
Deposited By: Lindsay Cleary
Deposited On:18 Jul 2007
Last Modified:09 Mar 2020 13:19

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