主要内容:
典型的伽马暴宿主星系--小的不规则星系，O的丰度也比较低12 + log(O/H) = 8.1 (~1/5 Solar)。
不过有氢线，是IIp型的超新星。
精彩摘抄:
文章信息:
- · arXiv e-print (arXiv:1107.5043)
- · References in the Article
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| Title: |
| SN 2008jb: A "Lost" Core-Collapse Supernova in a Star-Forming Dwarf Galaxy at ~10 Mpc |
| Authors: |
| Prieto, Jose L.; Lee, J. C.; Drake, A. J.; McNaught, R.; Garradd, G.; Beacom, J. F.; Beshore, E.;Catelan, M.; Djorgovski, S. G.; Pojmanski, G.; Stanek, K. Z.; Szczygiel, D. M. |
| Publication: |
| eprint arXiv:1107.5043 |
| Publication Date: |
| 07/2011 |
| Origin: |
| ARXIV |
| Keywords: |
| Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Cosmology and Extragalactic Astrophysics |
| Comment: |
| 40 pages, 10 figures, submitted to ApJ |
| Bibliographic Code: |
| 2011arXiv1107.5043P |
Abstract
We present the discovery and follow-up observations of SN 2008jb, a core-collapse supernova in the dwarf irregular galaxy ESO 302-14 at 9.6 Mpc. This transient was missed by galaxy-targeted surveys and was only found in archival optical images obtained by CRTS and ASAS. It was detected shortly after explosion and reached a bright optical maximum, Vmax = 13.6 mag (M_Vmax ~ -16.5). The shape of the light curve shows a plateau of 100 days, followed by a drop of 1.4 mag in V-band to a decline with the approximate Co 56 decay slope, consistent with 0.04 Msun of Ni 56 synthesized in the explosion. A spectrum obtained 2 years after explosion shows a broad, boxy Halpha emission line, which is unusual for type IIP supernovae. We detect the supernova in archival Spitzer and WISE images obtained 8-14 months after explosion, which show clear signs of warm dust emission. The dwarf irregular host galaxy has a low gas-phase oxygen abundance, 12 + log(O/H) = 8.1 (~1/5 Solar), similar to those of the SMC and the hosts of long gamma-ray bursts and luminous core-collapse supernovae. We study the host environment using GALEX FUV, R-band, and Halpha images and find that the supernova occurred in a large star-formation complex. The morphology of the Halpha emission appears as a large shell (R = 350 pc) surrounding the FUV and optical emission. We estimate an age of ~9 Myr and a total mass of ~2 x 10^5 Msun for the star-formation complex. These properties are consistent with the expanding Halpha supershells observed in well-studied nearby dwarf galaxies, which are tell-tale signs of feedback from the cumulative effect of massive star winds and supernovae. The age estimated for the star-forming region suggests a relatively high-mass progenitor star with initial mass of ~20 Msun. We discuss the implications of these findings in the study of core-collapse supernova progenitors. (Abridged)
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