Day 41

Friday.  Gotta plan the outing tonight.  Gotta finish coding the binning fix, and get the gglens code going for the weekend!


1107.2145
Supernova 2000cb: high-energy version of SN 1987A
Utrobin, Chugai


* SNe type IIP:  Type II SN are sub-divided into two classes, depending on the shape of the light curve.  The light curve for a Type II-L supernovae shows a stead (linear) decline following the peak brightness.  Type II-P supernova has a distinctive flat streach during the decline.  For type IIL, expulsion of most of the hydrogen envelope of the progenitor star causes the lightcurve shape; for type IIP, due to the change in the opacity of the exterior layer.  Shock wave ionizes the hydrogen in the outer envelope, resulting in a significant increase in opacity, preventing the photons from escaping, until the hydrogen cools enough to recombine and become transparent.


Use hydro simulations of the SNe to compare 1987A and 2000cb (IIP SNe from blue supergiants) to describe light curve and spectroscopic data.  Assume 35 R_sun, 22.3 M_sun ejecta, 4.4e51 erg energy, Ni 56 mass of 0.083 M_sun; estimated progenitor mass: 24-28 M_sun.  Dome-like light curves are entirely powered by radioactive decay, unlike normal type IIP supernovae, where the plateau is dominated by the internal energy deposited after the shock wave propagation through the pre-supernova.  Find signatures of explosion asymmetry in the photospheric and nebular spectra.  "The explosion energy of SN 2000cb is higher by a factor of three compared to SN 1987A, which poses a serious problem for explosion mechanisms of type IIP supernovae."


* that last sentence is not clear at all what they mean.  What serious problem?  It sounds more like a classification problem than a type IIP explosion mechanism problem to me.  Why is the factor of three a problem?