Related papers: A transient radio source consistent with a merger-…
When a relativistic jet is launched following the core-collapse of a star, its interaction with the stellar envelope leads to the formation of a hot cocoon, which produces various viewing-angle-dependent observational phenomena following…
Kilonovae are a rare class of astrophysical transients powered by the radioactive decay of nuclei heavier than iron, synthesized in the merger of two compact objects. Over the first few days, the kilonova evolution is dominated by a large…
Context: The long-standing question concerning jetted subgalactic-size (JSS) radio sources is whether they will evolve into large radio galaxies, die before escaping the host galaxy, or remain indefinitely confined to their compact size.…
When a massive star ends its life, its core collapses, forming a neutron star or black hole and producing some of the most energetic explosions in the universe. Core-collapse supernovae and long-duration gamma-ray bursts are the violent…
The neutron star zoo comprises several sub-populations that range from energetic magnetars and thermally emitting X-ray neutron stars to radio-emitting pulsars. Despite studies over the last five decades, it has been challenging to obtain a…
A supra-massive neutron star (NS) spinning extremely rapidly could survive from a merger of NS-NS binary. The spin-down of this remnant NS that is highly magnetized would power the isotropic merger ejecta to produce a bright mergernova…
Recent detections of kilonova-like emission following long-duration gamma-ray bursts GRB211211A and GRB230307A have been interpreted as originating from the merger of two neutron stars. In this work, we demonstrate that these observations…
The rapid time variability of gamma-ray bursts implies the sources are very compact, and the peak luminosities are so high that some matter must be ejected at ultra-relativistic speeds. The very large Lorentz factors of the bulk flow are…
Fast ejecta expelled in binary neutron star (NS) mergers or energetic supernovae (SNe) should produce late-time synchrotron radio emission as the ejecta shocks into the surrounding ambient medium. Models for such radio flares typically…
We study the optical and near-infrared luminosities and detectability of radioactively powered electromagnetic transients ('macronovae') occuring in the aftermath of binary neutron star and neutron star black hole mergers. We explore the…
It is believed that dual active galactic nuclei (dual AGN) will form during galaxies merge. Studying dual-AGN emission can provide valuable insights into galaxy merging and evolution. To investigate parsec-scale radio emission properties,…
Core-collapse supernovae are one of the most energetic events in the universe ($10^{46} J$). When a massive star (M $>$ 8 M$_{\odot}$) ignites its last fusion stage where silicon fusion makes iron, its end is then very close. Basically, the…
We study the radio signals generated when an axion star enters the magnetosphere of a neutron star. As the axion star moves through the resonant region where the plasma-induced photon mass becomes equal to the axion mass, the axions can…
Massive stars end their lives as core-collapse supernovae, amongst which some extremes are broad-lined type Ic supernovae from Wolf-Rayet stars associated with long-duration gamma-ray bursts (LGRBs) having powerful relativistic jets. Their…
The connection between compact object mergers and some extragalactic fast X-ray transients (FXRTs) has long been hypothesized, but never ultimately established. In this work, we investigate two FXRTs, the LEIA X-ray Transient LXT 240402A…
Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure, and the disintegration of the whole white dwarf. It…
Several fast radio bursts have been discovered recently, showing a bright, highly dispersed millisecond radio pulse. The pulses do not repeat and are not associated with a known pulsar or gamma-ray burst. The high dispersion suggests…
Supernovae provide a backdrop from which we can probe the end state of stellar evolution in the final years before the progenitor star explodes. As the shock from the supernova expands, the timespan of mass loss history we are able to probe…
The binary neutron star merger GW170817 was accompanied by radiation across the electromagnetic spectrum and localized to the galaxy NGC 4993 at a distance of 41+/-3 Mpc. The radio and X-ray afterglows of GW170817 exhibited delayed onset, a…
Observations show that at least some gamma-ray bursts (GRBs) happen simultaneously with core-collapse supernovae (SNe), thus linking by a common thread nature's two grandest explosions. We review here the growing evidence for and…