dc.contributor.author |
Kantharia, N. G |
|
dc.contributor.author |
Anupama, G. C |
|
dc.contributor.author |
Subramanian, P |
|
dc.date.accessioned |
2009-01-28T16:22:38Z |
|
dc.date.available |
2009-01-28T16:22:38Z |
|
dc.date.issued |
2005 |
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dc.identifier.citation |
B. Sripathi Acharya, Sunil Gupta, P. Jagadeesan, Atul Jain, S. Karthikeyan, Samuel Morris, and Suresh Tonwar., eds., Proceedings of the 29th International Cosmic Ray Conference. August 3 - 10, 2005, Pune, pp. 245 - 248 |
en |
dc.identifier.uri |
http://hdl.handle.net/2248/4292 |
|
dc.description.abstract |
Radio observations of the nova remnant of GK Per around 1985 (epoch 1) have shown it to have a spectral index of -0.4 (S propto nu^alpha) at frequencies <1.4 GHz and a spectral index of -0.7 at frequencies >1.4 GHz (Seaquist et al 1989, Biermann et al 1995). This spectrum is either due to secondary electrons from p-p interactions (Biermann et al 1995) or due to the presence of at least two electron populations which dominate the emission at different frequencies. Our radio observations (Anupama & Kantharia 2005) of the remnant of GK Persei using the Giant Metrewave Radio Telescope (GMRT) and archival Very Large Array (VLA) data show that the nova remnant has a low frequency (<1.3 GHz) spectral index alpha ~ -0.85 (in 2003; epoch 3) and a high frequency spectral index of alpha ~ -0.7 (1997; epoch 2). Moreover the higher frequencies show an annual secular decrease of ~ 2.1 % between epochs 1 and 2 whereas there is no change at 0.33 GHz. This suggests a significant evolution of the spectrum over 20 years. In this paper, we discuss a possible physical basis for this spectral evolution based on a comparison of the synchrotron loss and electron acceleration timescales. |
en |
dc.language.iso |
en |
en |
dc.publisher |
Tata Institute of Fundamental Research |
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dc.relation.ispartofseries |
International Cosmic Ray Conference, Vol. 3 |
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dc.relation.uri |
http://adsabs.harvard.edu/abs/2005ICRC....3..245K |
en |
dc.subject |
Cosmic ray |
en |
dc.subject |
Electron acceleration |
en |
dc.subject |
Remnant of nova |
en |
dc.subject |
GK Persei |
en |
dc.title |
Cosmic ray electron acceleration in the remnant of nova GK Persei? |
en |
dc.type |
Article |
en |