VLA Observations of J1228+441, a Luminous Supernova Remnant in NGC 4449

The luminous, oxygen-rich supernova remnant J1228+441 is located in the irregular galaxy NGC 4449 and has been observed at radio wavelengths for 30 years. An analysis of recent Very Large Array (VLA) observations of NGC 4449, combined with VLA archive data and previously published VLA and Westerbork...

Full description

Saved in:
Bibliographic Details
Published in:The Astronomical journal 2007-05, Vol.133 (5), p.2156-2162
Main Authors: Lacey, Christina K, Goss, W. M, Mizouni, Leila K
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The luminous, oxygen-rich supernova remnant J1228+441 is located in the irregular galaxy NGC 4449 and has been observed at radio wavelengths for 30 years. An analysis of recent Very Large Array (VLA) observations of NGC 4449, combined with VLA archive data and previously published VLA and Westerbork Synthesis Radio Telescope observations, yields light curves at 6 and 20 cm from 1972 to 2002. The light curves at all radio frequencies exhibit a marked decline in radio emission, confirming past findings. This paper presents and discusses the radio light curves and spectral index a variations from 1972 to 2002, where Sn {proportional to} n-a, and compares J1228+441 with other radio supernovae. The spectral index of J1228+441 appears to have steepened in the last 5 years at higher frequencies, from a = 0.64 - 0.02 in 1996 to a = 1.01 - 0.02 in 2001-2002.
ISSN:1538-3881
0004-6256
1538-3881
DOI:10.1086/512187