The first ICRANet catalog of binary-driven hypernovae

Abstract

In a series of recent publications, scientists from ICRANet, led by professor Remo Ruffini, have reached a novel comprehensive picture of gamma-ray bursts (GRBs) thanks to their development of a series of new theoretical approaches. Among those, the induced gravitational collapse (IGC) paradigm explains a class of energetic, long-duration GRBs associated with Ib/c supernovae (SN), recently named binary-driven hypernovae (BdHNe). BdHNe have a well defined set of observational features which allow to identify them. Among them, the main two are: 1) long duration of the GRB explosion, namely larger than 2 s in the rest frame; 2) a total energy, released in all directions by the GRB explosion, larger than 10 52 ergs. A striking result is the observation, in the BdHNe sources, of a universal late time power-law decay in the X-rays luminosity after 10 4 s, with typical decaying slope of ∼ 1.5. This leads to the possible establishment of a new distance indicator having redshift up to z ∼ 8. Thanks to this novel theoretical and observational understanding, it was possible for ICRANet scientists to build the firstst BdHNe catalog, composed by the 345 BdHNe identified up to the end of 2016. Keywords: supernovae: general -binaries: general -gamma-ray burst: general -stars: neutron TOWARDS A FIRST CATALOG OF BINARY-DRIVEN HYPERNOVAEThe first observations by the BATSE instrument on board the Compton γ-ray Observatory satellite have evidenced what has later become known as the prompt radiation of GRBs. On the basis of their hardness as well as their duration, GRBs were initially classified into short and long in an epoch when their cosmological nature was still being debated (Mazets et al. 1981;Klebesadel 1992;Dezalay et al. 1992;Kouveliotou et al. 1993;Tavani 1998).The advent of the BeppoSAX satellite (Boella et al. 1997) introduced a new approach to GRBs by introducing joint observations in the X-rays and γ-rays thanks to its instruments: the Gamma-ray Burst Monitor (40-700 keV), the Wide Field Cameras (2-26 keV), and the Narrow Field Instruments (2-10 keV). The unexpected discovery of a well separate component in the GRB soon appeared: the afterglow, namely a radiation lasting up to 10 5 -10 6 s after the emission of the prompt radiation (see Costa et al. 1997a,b;Frontera et al. 1998Frontera et al. , 2000de Pasquale et al. 2006). Beppo-SAX clearly indicated the existence of a power law behavior in the late X-ray emission (LXRE).The coming of the Swift satellite (Gehrels et al. 2004;Evans et al. 2007Evans et al. , 2010, significantly extending the ob- servation energy band to the X-ray band thanks to its X-ray Telescope (XRT band: 0.3-10 keV), has allowed us for the first time to uncover the unexplored region between the end of the prompt radiation and the power-law late X-ray behavior discovered by BeppoSAX : in some long GRBs, a steep decay phase was observed leading to a plateau followed then by a typical LXRE power law behavior (Evans et al. 2007(Evans et al. , 2010.Recently, Pisani et al. (2013) noticed the unex...