@article {2014MNRAS.440.1052K, title = {{The nature of supernovae 2010O and 2010P in Arp 299 - I. Near-infrared and optical evolution}}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {440}, year = {2014}, month = {may}, pages = {1052-1066}, abstract = {We present near-infrared and optical photometry, plus optical spectroscopy of two stripped-envelope supernovae (SNe) 2010O and 2010P that exploded in two different components of an interacting luminous infrared galaxy Arp 299 within only a few days of one another. SN 2010O is found to be photometrically and spectroscopically similar to many normal Type Ib SNe and our multiwavelength observations of SN 2010P suggest it to be a Type IIb SN. No signs of clear hydrogen features or interaction with the circumstellar medium are evident in the optical spectrum of SN 2010P. We derive estimates for the host galaxy line-of-sight extinctions for both SNe, based on both light curve and spectroscopic comparison finding consistent results. These methods are also found to provide much more robust estimates of the SN host galaxy reddening than the commonly used empirical relations between extinction and equivalent width of Na I D absorption features. The SN observations also suggest that different extinction laws are present in different components of Arp 299. For completeness, we study high-resolution pre-explosion images of Arp 299 and find both SNe to be close to, but not coincident with, extended sources that are likely massive clusters. A very simple model applied to the bolometric light curve of SN 2010O implies a rough estimate for the explosion parameters of E$_{k}$ {\ap} 3 {\times} 10$^{51}$ erg, M$_{ej}$ {\ap} 2.9 M$_{\&sun;}$ and M$_{Ni}$ {\ap} 0.16 M$_{\&sun;}$.}, keywords = {galaxies: individual: Arp 299, galaxies: starburst, infrared: galaxies, supernovae: general, supernovae: individual: SN 2010O, supernovae: individual: SN 2010P}, doi = {10.1093/mnras/stt2289}, url = {http://adsabs.harvard.edu/abs/2014MNRAS.440.1052K}, author = {Kankare, E. and Mattila, S. and Ryder, S. and Fraser, M. and Pastorello, A. and Elias-Rosa, N. and Romero-Ca{\~n}izales, C. and Alberdi, A. and Hentunen, V.-P. and R. Herrero-Illana and Kotilainen, J. and M. A. P{\'e}rez-Torres and V{\"a}is{\"a}nen, P.} } @article {2014MNRAS.440.1067R, title = {{The nature of supernovae 2010O and 2010P in Arp 299 - II. Radio emission}}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {440}, year = {2014}, pages = {1067-1079}, abstract = {We report radio observations of two stripped-envelope supernovae (SNe), 2010O and 2010P, which exploded within a few days of each other in the luminous infrared galaxy Arp 299. Whilst SN 2010O remains undetected at radio frequencies, SN 2010P was detected (with an astrometric accuracy better than 1 milli arcsec in position) in its optically thin phase in epochs ranging from {\tilde}1 to {\tilde}3 yr after its explosion date, indicating a very slow radio evolution and a strong interaction of the SN ejecta with the circumstellar medium. Our late-time radio observations towards SN 2010P probe the dense circumstellar envelope of this SN, and imply dot$\{$M$\}$ [ $\{$M\_$\{${\sun}$\}$ yr\^{}$\{$-1$\}$$\}$] / v\_$\{$wind$\}$ [10 km s\^{}$\{$-1$\}$] =(3.0-5.1) {\times} 10$^{-5}$, with a 5 GHz peak luminosity of {\tilde}1.2 {\times} 10$^{27}$ erg s$^{- 1}$ Hz$^{- 1}$ on day {\tilde}464 after explosion. This is consistent with a Type IIb classification for SN 2010P, making it the most distant and most slowly evolving Type IIb radio SN detected to date.}, keywords = {galaxies: individual: Arp 299, galaxies: starburst, radio continuum: galaxies, supernovae: general, supernovae: individual: SN 2010O, supernovae: individual: SN 2010P}, doi = {10.1093/mnras/stu430}, url = {http://adsabs.harvard.edu/abs/2014MNRAS.440.1067R}, author = {Romero-Ca{\~n}izales, C. and R. Herrero-Illana and M. A. P{\'e}rez-Torres and Alberdi, A. and Kankare, E. and Bauer, F.~E. and Ryder, S.~D. and Mattila, S. and Conway, J.~E. and Beswick, R.~J. and Muxlow, T.~W.~B.} } @article {2010A\&A...519L...5P, title = {{Serendipitous discovery of the long-sought active galactic nucleus in Arp 299-A}}, journal = {Astronomy and Astrophysics}, volume = {519}, year = {2010}, month = {sep}, pages = {L5}, abstract = {Context. The dusty nuclear regions of luminous infra-red galaxies (LIRGs) are heated by either an intense burst of massive star formation, an active galactic nucleus (AGN), or a combination of both. Disentangling the contribution of each of those putative dust-heating agents is a challenging task, and direct imaging of the innermost few pc can only be accomplished at radio wavelengths, using very high-angular resolution observations.
Aims: We observed the nucleus A of the interacting starburst galaxy Arp 299, using very long baseline interferometry (VLBI) radio observations at 1.7 and 5.0 GHz. Our aim was to characterize the compact sources in the innermost few pc region of Arp 299-A, as well as to detect recently exploded core-collapse supernovae.
Methods: We used the European VLBI Network (EVN) to image the 1.7 and 5.0 GHz compact radio emission of the parsec-scale structure in the nucleus of Arp 299-A with milliarcsecond resolution.
Results: Our EVN observations show that one of the compact VLBI sources, A1, previously detected at 5.0 GHz, has a flat spectrum between 1.7 and 5.0 GHz and is the brightest source at both frequencies. Our 1.7 GHz EVN image shows also diffuse, low-surface brightness emission extending westwards from A1 and displays a prominent core-jet structure.
Conclusions: The morphology, radio luminosity, spectral index and ratio of radio-to-X-ray emission of the A1-A5 region is consistent with a low-luminosity AGN (LLAGN), and rules out the possibility that it is a chain of young radio supernovae (RSNe) and supernova remnants (SNRs). We therefore conclude that A1-A5 is the long-sought AGN in Arp 299-A. This finding may suggest that both starburst and AGN are frequently associated phenomena in mergers.}, keywords = {galaxies: individual: Arp 299, galaxies: starburst, Galaxy: nucleus, radiation mechanisms: non-thermal, radio continuum: stars}, doi = {10.1051/0004-6361/201015462}, url = {http://adsabs.harvard.edu/abs/2010A\%26A...519L...5P}, author = {M. A. P{\'e}rez-Torres and Alberdi, A. and Romero-Ca{\~n}izales, C. and Bondi, M.} }