@article {2011A\&A...529A..47M,
	title = {{Electron cooling and the connection between expansion and flux-density evolution in radio supernovae}},
	journal = {Astronomy and Astrophysics},
	volume = {529},
	year = {2011},
	month = {may},
	pages = {A47},
	abstract = {{Radio supernovae (RSNe) are weak and rare events. Their typical maximum radio luminosities are of the order of only 10$^{27}$ erg s$^{-1}$ Hz$^{-1}$. There are, however, very few cases of relatively bright (and/or close) RSNe, from which the expansion of the shock and the radio light curves at several frequencies have been monitored covering several years. Applying the standard model of radio emission from supernovae, it is possible to relate the defining parameters of the modelled expansion curve to those of the modelled light curves in a simple algebraic way by assuming an evolution law for the magnetic field and for the energy density of the population of synchrotron-emitting electrons. However, cooling mechanisms of the electrons may considerably affect this connection between light curves and expansion curve, and lead to wrong conclusions on the details of the electron acceleration and/or on the CSM radial density profile. We study how electron cooling modifies the flux-density decay rate of RSNe for a set of plausible/realistic values of the magnetic field and for different expansion regimes. We use these results to estimate the magnetic fields of different RSNe observed to date and compare them to those obtained by assuming energy equipartition between particles and magnetic fields. For some of the best monitored RSNe, for which deceleration measurements, optically thin spectral index, and power-law time decay have been observed (SN 1979C, SN 1986J, SN 1993J, and SN 2008iz), we find self-consistent solutions for the index of the power-law circumstellar density profile (s = 2 for all cases), the index of the power-law relativistic electron population (rather steep values},
	keywords = {acceleration of particles, radiation mechanisms: nonthermal, radio continuum: stars, supernovae: general},
	doi = {10.1051/0004-6361/201016105},
	url = {http://adsabs.harvard.edu/abs/2011A\%26A...529A..47M},
	author = {Mart{\'\i}-Vidal, I. and M. A. P{\'e}rez-Torres and Brunthaler, A.}
}
@article {2011A\&A...526A.142M,
	title = {{Radio emission of SN1993J: the complete picture. I. Re-analysis of all the available VLBI data}},
	journal = {Astronomy and Astrophysics},
	volume = {526},
	year = {2011},
	month = {feb},
	pages = {A142},
	abstract = {We have performed a complete re-calibration and re-analysis of all the available Very-Long-Baseline-Interferometry (VLBI) observations of supernova SN1993J, following an homogeneous and well-defined methodology. VLBI observations of SN1993J at 69 epochs, spanning 13 years, were performed by two teams, which used different strategies and analysis tools. The results obtained by each group are similar, but their conclusions on the supernova expansion and the shape and evolution of the emitting region differ significantly. From our analysis of the combined set of observations, we have obtained an expansion curve with unprecedented time resolution and coverage. We find that the data from both teams are compatible when analyzed with the same methodology. One expansion index (m$_{3}$ = 0.87 {\plusmn} 0.02) is enough to model the expansion observed at 1.7 GHz, while two expansion indices (m$_{1}$ = 0.933 {\plusmn} 0.010 and m$_{2}$ = 0.796 {\plusmn} 0.005), separated by a break time, t$_{br}$ = 390 {\plusmn} 30 days, are needed to model the data, at frequencies higher than 1.7 GHz, up to day \~{}4000 after explosion. We thus confirm the wavelength dependence of the size of the emitting region reported by one of the groups. We also find that all sizes measured at epochs later than day \~{}4000 after explosion are systematically smaller than our model predictions (i.e., an additional expansion index might be needed to properly model these data). We also estimate the fractional shell width (0.31 {\plusmn} 0.02, average of all epochs and frequencies) and the level of opacity to the radio emission by the ejecta. We find evidence of a spectral-index radial gradient in the supernova shell, which is indicative of a frequency-dependent ejecta opacity. Finally, we study the distribution and evolution of the azimuthal anisotropies (hot spots) found around the radio shell during the expansion. These anisotropies have intensities of \~{}20\% of the mean flux density of the shell, and appear to systematically evolve during the expansion.},
	keywords = {galaxies: individual: M 81, radio continuum: stars, supernovae: general, supernovae: individual: SN1993J},
	doi = {10.1051/0004-6361/200913831},
	url = {http://adsabs.harvard.edu/abs/2011A\%26A...526A.142M},
	author = {Mart{\'\i}-Vidal, I. and Marcaide, J.~M. and Alberdi, A. and Guirado, J.~C. and M. A. P{\'e}rez-Torres and Ros, E.}
}
@article {2011A\&A...526A.143M,
	title = {{Radio emission of SN1993J: the complete picture. II. Simultaneous fit of expansion and radio light curves}},
	journal = {Astronomy and Astrophysics},
	volume = {526},
	year = {2011},
	pages = {A143},
	abstract = {We report on a simultaneous modelling of the expansion and radio light curves of the supernova SN1993J. We developed a simulation code capable of generating synthetic expansion and radio light curves of supernovae by taking into consideration the evolution of the expanding shock, magnetic fields, and relativistic electrons, as well as the finite sensitivity of the interferometric arrays used in the observations. Our software successfully fits all the available radio data of SN 1993J with a standard emission model for supernovae, which is extended with some physical considerations, such as an evolution in the opacity of the ejecta material, a radial decline in the magnetic fields within the radiating region, and a changing radial density profile for the circumstellar medium starting from day 3100 after the explosion.},
	keywords = {acceleration of particles, galaxies: individual: M 81, radiation mechanisms: non-thermal, radio continuum: stars, supernovae: general, supernovae: individual: SN1993J},
	doi = {10.1051/0004-6361/201014517},
	url = {http://adsabs.harvard.edu/abs/2011A\%26A...526A.143M},
	author = {Mart{\'\i}-Vidal, I. and Marcaide, J.~M. and Alberdi, A. and Guirado, J.~C. and M. A. P{\'e}rez-Torres and Ros, E.}
}
@article {2011A\&A...535L..10M,
	title = {{VLBI observations of SN 2011dh: imaging of the youngest radio supernova}},
	journal = {Astronomy and Astrophysics},
	volume = {535},
	year = {2011},
	pages = {L10},
	abstract = {We report on the VLBI detection of supernova SN 2011dh at 22 GHz using a subset of the EVN array. The observations took place 14 days after the discovery of the supernova, thus resulting in a VLBI image of the youngest radio-loud supernova ever. We provide revised coordinates for the supernova with milli-arcsecond precision, linked to the ICRF. The recovered flux density is a factor \~{}2 below the EVLA flux density reported by other authors at the same frequency and epoch of our observations. This discrepancy could be due to extended emission detected with the EVLA or to calibration problems in the VLBI and/or EVLA observations.},
	keywords = {ISM: supernova remnants, radiation mechanisms: non-thermal, radio continuum: general, supernovae: general, supernovae: individual: SN 2011dh},
	doi = {10.1051/0004-6361/201118195},
	url = {http://adsabs.harvard.edu/abs/2011A\%26A...535L..10M},
	author = {Mart{\'\i}-Vidal, I. and Tudose, V. and Paragi, Z. and Yang, J. and Marcaide, J.~M. and Guirado, J.~C. and Ros, E. and Alberdi, A. and M. A. P{\'e}rez-Torres and Argo, M.~K. and van der Horst, A.~J. and Garrett, M.~A. and Stockdale, C.~J. and Weiler, K.~W.}
}
