SN 2005cs in M51 - II. Complete evolution in the optical and the near-infrared

Abstract

We present the results of the one‐year long observational campaign of the type II plateau SN 2005cs, which exploded in the nearby spiral galaxy M51 (the Whirlpool galaxy). This extensive data set makes SN 2005cs the best observed low‐luminosity, 56Ni‐poor type II plateau event so far and one of the best core‐collapse supernovae ever. The optical and near‐infrared spectra show narrow P‐Cygni lines characteristic of this SN family, which are indicative of a very low expansion velocity (about 1000 km s−1) of the ejected material. The optical light curves cover both the plateau phase and the late‐time radioactive tail, until about 380 d after core‐collapse. Numerous unfiltered observations obtained by amateur astronomers give us the rare opportunity to monitor the fast rise to maximum light, lasting about 2 d. In addition to optical observations, we also present near‐infrared light curves that (together with already published ultraviolet observations) allow us to construct for the first time a reliable bolometric light curve for an object of this class. Finally, comparing the observed data with those derived from a semi‐analytic model, we infer for SN 2005cs a 56Ni mass of about 3 × 10−3 M⊙, a total ejected mass of 8–13 M⊙ and an explosion energy of about 3 × 1050 erg.

The Development of Explosions in Axisymmetric Ab Initio Core-Collapse Supernova Simulations of 12–25 Stars

“…Similar results were obtained by Tsvetkov et al (2006) from their observations of the supernova and their use of the IIP-analytical model of Popov (1993) and the simulations of Litvinova & Nadezhin (1985). Pastorello et al (2009) analyzed an extensive data set to estimate M 10 ZAMS » -15 M  by a semi-analytic fit of the data to the model of Zampieri et al (2003). Finally, Utrobin & Chugai (2008), with radiation-hydrodynamics modeling, obtain a larger M ZAMS of 17.2-19.2 M  .…”

“…This requires corrections for estimated mass loss during progenitor evolution and a compact remnant mass estimate. Since this method requires high-quality photometric and spectroscopic data, it has only been applied to a handful of events where such data are available (e.g., Zampieri et al 2003;Baklanov et al 2005;Utrobin 2007;Utrobin & Chugai 2008, 2009Pastorello et al 2009;Dall'Ora et al 2014). Typically, these models of explosions in RSGs predict significantly higher ZAMS masses than those obtained by direct imaging.…”

Improved distance determination to M 51 from supernovae 2011dh and 2005cs

“…We have collected the BVRI light curves from Pastorello et al (2009). The spectra published in the same paper were kindly provided to us by Andrea Pastorello.…”

“…The zero-points for each night were tied to local tertiary standard stars around M 51 collected from Pastorello et al (2009).…”

“…1, the moment of shock breakout (t 0 ) is accurately known for both SNe. We have adopted t 0 = 2 453 549.0 JD (Pastorello et al 2009) and t 0 = 2 455 712.5 JD (Arcavi et al 2011) for SN 2005cs and SN 2011dh, respectively. We applied Eq.…”