Infrared supernova remnants and their infrared-to-X-ray flux ratios

Journal Article · Sun Apr 10 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/821/1/20· OSTI ID:22890085

Koo, Bon-Chul; Jeong, Il-Gyo; Kim, Hyun-Jeong ^[1]; Lee, Jae-Joon ^[2]

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1. Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
2. Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

Recent high-resolution infrared space missions have revealed supernova remnants (SNRs) of diverse morphology in infrared (IR) dust emission that are often very different from their X-ray appearance. The observed range of infrared-to-X-ray (IRX) flux ratios of SNRs is also wide. For a sample of 20 Galactic SNRs, we obtain their IR and X-ray properties and investigate the physical causes for such large differences. We find that the observed IRX flux ratios (R{sub IRX,obs}) are related to the IRX morphology, with SNRs with the largest R{sub IRX,obs} showing anticorrelated IRX morphology. By analyzing the relation of R{sub IRX,obs} to X-ray and IR parameters, we show that the R{sub IRX,obs} of some SNRs agrees with theoretical ratios of SNR shocks in which dust grains are heated and destroyed by collisions with plasma particles. For the majority of SNRs, however, R{sub IRX,obs} values are either significantly smaller or significantly larger than the theoretical ratios. The latter SNRs have relatively low dust temperatures. We discuss how the natural and/or environmental properties of SNRs could have affected the IRX flux ratios and the IRX morphology of these SNRs. We conclude that the SNRs with largest R{sub IRX,obs} are probably located in a dense environment and that their IR emission is from dust heated by shock radiation rather than by collisions. Our result suggests that the IRX flux ratio, together with dust temperature, can be used to infer the nature of unresolved SNRs in external galaxies.

• OSTI ID: 22890085
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 821; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COLLISIONS
COSMIC DUST
EMISSION
GALAXIES
INFRARED RADIATION
PLASMA
SHOCK WAVES
SPACE
SUPERNOVA REMNANTS