Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-05-28
Astronomy and Astrophysics
Astrophysics
Accepted for publication in A&A (22/05/07)
Scientific paper
10.1051/0004-6361:20077522
We report on 8.4GHz Very Long Baseline Interferometry (VLBI) observations of the type II-P supernova SN2004et in the spiral galaxy NGC 6946, made on 20 February 2005 (151 days after explosion). The Very Large Array (VLA) flux density was 1.23$\pm$0.07 mJy, corresponding to an isotropic luminosity at 8.4GHz of (4.45$\pm$0.3)$\times10^{25}$ erg s$^{-1}$ Hz$^{-1}$ and a brightness temperature of (1.3$\pm$0.3)$\times10^{8}$ K. We also provide an improved source position, accurate to about 0.5 mas in each coordinate. The VLBI image shows a clear asymmetry. From model fitting of the size of the radio emission, we estimate a minimum expansion velocity of 15,700$\pm$2,000 km s$^{-1}$. This velocity is more than twice the expected mean expansion velocity estimated from a synchrotron self-absorbed emission model, thus suggesting that synchrotron self-absorption is not relevant for this supernova. With the benefit of an optical spectrum obtained 12 days after explosion, we favor an emission model which consists of two hot spots on an underlying expanding shell of width comparable to that of SN 1993J.
Alberdi Antonio
Argo Megan K.
Beswick Rob J.
Guirado Jose C.
Lara Liana
No associations
LandOfFree
8.4GHz VLBI observations of SN2004et in NGC6946 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with 8.4GHz VLBI observations of SN2004et in NGC6946, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 8.4GHz VLBI observations of SN2004et in NGC6946 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-447712