8.4 GHz VLBI observations of SN 2004et in NGC 6946
We report on 8.4 GHz very-long-baseline-interferometry (VLBI) observations of the type II-P supernova SN 2004et 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 ± 0.07 mJy, corresponding to an isotropic luminosity at...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
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EDP Sciences
2007
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| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.11937/26650 |
| _version_ | 1848752046601142272 |
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| author | Marti-Vidal, I. Marcaide, J. Alberdi, A. Guirado, J. Lara, L. Prez-Torres, M. Ros, E. Argo, Megan Beswick, R. Muxlow, T. Pedlar, A. Shapiro, I. Stockdale, C. Sramek, R. Weiler, K. Vinko, J. |
| author_facet | Marti-Vidal, I. Marcaide, J. Alberdi, A. Guirado, J. Lara, L. Prez-Torres, M. Ros, E. Argo, Megan Beswick, R. Muxlow, T. Pedlar, A. Shapiro, I. Stockdale, C. Sramek, R. Weiler, K. Vinko, J. |
| author_sort | Marti-Vidal, I. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We report on 8.4 GHz very-long-baseline-interferometry (VLBI) observations of the type II-P supernova SN 2004et 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 ± 0.07 mJy, corresponding to an isotropic luminosity at 8.4 GHz of (4.45±0.3) 10 25 erg s-1 Hz-1 and a brightness temperature of (1.3 ± 0.3) 108 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 ± 2000 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. |
| first_indexed | 2025-11-14T08:02:24Z |
| format | Journal Article |
| id | curtin-20.500.11937-26650 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:02:24Z |
| publishDate | 2007 |
| publisher | EDP Sciences |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-266502017-09-13T15:55:19Z 8.4 GHz VLBI observations of SN 2004et in NGC 6946 Marti-Vidal, I. Marcaide, J. Alberdi, A. Guirado, J. Lara, L. Prez-Torres, M. Ros, E. Argo, Megan Beswick, R. Muxlow, T. Pedlar, A. Shapiro, I. Stockdale, C. Sramek, R. Weiler, K. Vinko, J. galaxies individual radio continuum supernovae stars NGC 6946 SN We report on 8.4 GHz very-long-baseline-interferometry (VLBI) observations of the type II-P supernova SN 2004et 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 ± 0.07 mJy, corresponding to an isotropic luminosity at 8.4 GHz of (4.45±0.3) 10 25 erg s-1 Hz-1 and a brightness temperature of (1.3 ± 0.3) 108 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 ± 2000 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. 2007 Journal Article http://hdl.handle.net/20.500.11937/26650 10.1051/0004-6361:20077522 EDP Sciences fulltext |
| spellingShingle | galaxies individual radio continuum supernovae stars NGC 6946 SN Marti-Vidal, I. Marcaide, J. Alberdi, A. Guirado, J. Lara, L. Prez-Torres, M. Ros, E. Argo, Megan Beswick, R. Muxlow, T. Pedlar, A. Shapiro, I. Stockdale, C. Sramek, R. Weiler, K. Vinko, J. 8.4 GHz VLBI observations of SN 2004et in NGC 6946 |
| title | 8.4 GHz VLBI observations of SN 2004et in NGC 6946 |
| title_full | 8.4 GHz VLBI observations of SN 2004et in NGC 6946 |
| title_fullStr | 8.4 GHz VLBI observations of SN 2004et in NGC 6946 |
| title_full_unstemmed | 8.4 GHz VLBI observations of SN 2004et in NGC 6946 |
| title_short | 8.4 GHz VLBI observations of SN 2004et in NGC 6946 |
| title_sort | 8.4 ghz vlbi observations of sn 2004et in ngc 6946 |
| topic | galaxies individual radio continuum supernovae stars NGC 6946 SN |
| url | http://hdl.handle.net/20.500.11937/26650 |