Related papers: X-ray-powered macronovae
Gamma Ray Bursts as recent GRB990123 and GRB990510 are observed to occur in cosmic volumes with a corresponding output reaching, for isotropic explosions, energies as large as two solar masses annihilation. These energies are underestimated…
Mergers of double neutron stars (DNSs) could lead to the formation of a long-lived massive remnant NS, which has been previously suggested to explain the AT 2017gfo kilonova emission in the famous GW170817 event. For an NS-affected…
We describe the afterglows of the long gamma-ray-burst (GRB) 130427A within the context of a binary-driven hypernova (BdHN). The afterglows originate from the interaction between a newly born neutron star ($\nu$NS), created by an Ic…
Gamma-ray bursts can appear to be a hundred times as luminous as supernovae, but their underlying energy source(s) have remained a mystery. However, there has been evidence for some time now of an association of gamma-ray bursts with…
Compact binary mergers, with neutron stars or neutron star and black-hole components, are thought to produce various electromagnetic counterparts: short gamma-ray bursts (GRBs) from ultra-relativistic jets followed by broadband afterglow;…
Binary neutron star mergers (BNS) produce high-energy emissions from several physically different sources, including a gamma-ray burst (GRB) and its afterglow, a kilonova, and, at late times, a remnant many parsecs in size. Ionizing…
Long-duration ($>2$ s) $\gamma$-ray bursts that are believed to originate from the death of massive stars are expected to be accompanied by supernovae. GRB 060614, that lasted 102 s, lacks a supernova-like emission down to very stringent…
One of the most promising electromagnetic signatures of compact object mergers are kilonovae: approximately isotropic radioactively-powered transients that peak days to weeks post-merger. Key uncertainties in modeling kilonovae include the…
The observation of a radioactively powered kilonova AT~2017gfo associated with the gravitational wave-event GW170817 from binary neutron star merger proves that these events are ideal sites for the production of heavy $r$-process elements.…
Kilonovae are a novel class of astrophysical transients, and the only observationally-confirmed site of rapid neutron capture nucleosynthesis (the r-process) in the Universe. To date, only a handful of kilonovae have been detected, with…
We report observations of the optical counterpart of the long gamma-ray burst (LGRB) GRB 221009A. Due to the extreme rarity of being both nearby ($z = 0.151$) and highly energetic ($E_{\gamma,\mathrm{iso}} \geq 10^{54}$ erg), GRB 221009A…
The first X-ray afterglow for a short (~30 ms), hard gamma-ray burst was detected by Swift on 9 May 2005 (GRB 050509b). No optical or radio counterpart was identified in follow-up observations. The tentative association of the GRB with a…
Short gamma-ray bursts require a rotating black hole, surrounded by a magnetized relativistic accretion disk, such as the one formed by coalescing binary neutron stars or neutron star - black hole systems. The accretion onto a Kerr black…
A binary neutron star (BNS) merger has been widely argued to be one of the progenitors of a short gamma-ray burst (SGRB). This central engine can be verified if its gravitational-wave (GW) event is detected simultaneously. Once confirmed,…
The 2017 detection of a kilonova coincident with gravitational-wave emission has identified neutron star mergers as the major source of the heaviest elements, and dramatically constrained alternative theories of gravity. Observing a…
Given an increasing number of gamma-ray bursts accompanied by potential kilonovae there is a growing importance to advance modelling of kilonova afterglows. In this work, we investigate how the presence of two electron populations that…
Kilonova is an optical-infrared transient powered by the radioactive decay of heavy nuclei from binary neutron star mergers. Its observational characteristics depend on the mass and the nuclide composition of meger ejecta, which are…
In several gamma-ray bursts (GRBs) excess emission, in addition to the standard synchrotron afterglow spectrum, has been discovered in the early time X-ray observations. It has been proposed that this excess comes from black body emission,…
Context. The coincident detection of GW170817 and GRB170817A marked a milestone for the connection between binary neutron star (BNS) mergers and short gamma-ray bursts (sGRBs). These mergers can lead to the formation of a black hole…
Over the last few years, there has been an increasing interest in sub-solar mass black holes due to their potential to provide valuable information about cosmology or the black hole population. Motivated by this, we study observable…