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A mildly relativistic radio jet from the otherwise normal type Ic supernova 2007gr


Paragi, Z and Taylor, GB and Kouveliotou, C and Granot, J and Ramirez-Ruiz, E and Bietenholz, M and van der Horst, AJ and Pidopryhora, Y and van Langevelde, HJ and Garrett, MA and Szomoru, A and Argo, MK and Bourke, S and Paczynski, B, A mildly relativistic radio jet from the otherwise normal type Ic supernova 2007gr, Nature, 463 pp. 516-518. ISSN 0028-0836 (2010) [Refereed Article]

Copyright Statement

Copyright 2010 MacMillan Publishing Group

DOI: doi:10.1038/nature08713


The class of type Ic supernovae have drawn increasing attention since 1998 owing to their sparse association (only four so far) with long duration γ-ray bursts (GRBs)1, 2, 3, 4. Although both phenomena originate from the core collapse of a massive star, supernovae emit mostly at optical wavelengths, whereas GRBs emit mostly in soft γ-rays or hard X-rays. Though the GRB central engine generates ultra-relativistic jets, which beam the early emission into a narrow cone, no relativistic outflows have hitherto been found in type Ib/c supernovae explosions, despite theoretical expectations5, 6, 7 and searches8. Here we report radio (interferometric) observations that reveal a mildly relativistic expansion in a nearby type Ic supernova, SN 2007gr. Using two observational epochs 60 days apart, we detect expansion of the source and establish a conservative lower limit for the average apparent expansion velocity of 0.6c. Independently, a second mildly relativistic supernova has been reported9. Contrary to the radio data, optical observations10, 11, 12, 13 of SN 2007gr indicate a typical type Ic supernova with ejecta velocities ~6,000 km s-1, much lower than in GRB-associated supernovae. We conclude that in SN 2007gr a small fraction of the ejecta produced a low-energy mildly relativistic bipolar radio jet, while the bulk of the ejecta were slower and, as shown by optical spectropolarimetry14, mildly aspherical.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Stellar astronomy and planetary systems
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Pidopryhora, Y (Dr Yurii Pidopryhora)
ID Code:95781
Year Published:2010
Web of Science® Times Cited:45
Deposited By:Mathematics and Physics
Deposited On:2014-10-08
Last Modified:2014-12-02

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