@inproceedings{e7a7305c1e33452f94566db7ca02f702,
title = "Four epochs of VLBA/HSA observations of SN 2001em",
abstract = "SN 2001em is a peculiar supernova (SN) which has been reclassified from Type Ib/c to IIn. We deduced the limits for its proper motion as well as the expansion velocity by analysing four epochs of VLBI observations. Our 2 sigma upper limit of its proper motion is (23,000 30,000) km s(-1) and for the expansion velocity is 9000 km s(-1) with 95% confidence. Thus we confirm the analysis of Bietenholz & Bartel that this was not a jet-driven gamma my burst event. The supernova is unresolved 6 years after the explosion. We find no evidence for the existence of a jet. These values suggest interaction of the SN ejecta with a dense circumstellar medium. VLA observations of the flux density over 4 years of observations show a power law decay.",
keywords = "supernova : core collapse, type IIn, sn2001em, techniques : image processing, VLBI, instruments : VLBA",
author = "Schinzel, {F. K.} and Taylor, {G. B.} and Stockdale, {C. J.} and J. Granot and E. Ramirez-Ruiz",
note = "Original paper can be found at: http://proceedings.aip.org/proceedings/ Copyright AIP [Full text of this paper is not available in the UHRA]; GAMMA-RAY BURSTS 2007 ; Conference date: 05-11-2007 Through 09-11-2007",
year = "2008",
doi = "10.1063/1.2943520",
language = "English",
isbn = "978-0-7354-0533-2",
volume = "1000",
series = "AIP Conference Proceedings",
publisher = "American Institute of Physics (AIP)",
pages = "509--512",
editor = "M Galassi and D Palmer and E Fenimore",
booktitle = "Gamma-ray bursts 2007",
address = "United States",
}