Related papers: Internal Shocks from Variable Outflows in Classica…
Shocks in gamma-ray emitting classical novae are expected to produce bright thermal and non-thermal X-rays. We test this prediction with simultaneous NuSTAR and Fermi/LAT observations of nova V906 Car, which exhibited the brightest GeV…
Nova shocks behave like scaled-down supernova remnant shocks with a lifetime of only a few weeks or months, thereby providing a unique opportunity to study the dynamics of non-relativistic shocks as well as the shock acceleration physics.…
A lot of information concerning the mechanism of nova explosions will be extracted from the possible future observations with INTEGRAL. In order to be prepared for this task, we are performing detailed models of the gamma-ray emission of…
We have computed a spherically symmetric model for the interaction of matter ejected during the outburst of a classical nova with the stellar wind from its optical component.This model is used to describe the intense X-ray outburst (the…
Classical novae occur on the surface of an accreting white dwarf in a binary system. After ejection of a fraction of the envelope and when the expanding shell becomes optically thin to X-rays, a bright source of supersoft X-rays arises,…
A significant fraction of novae exhibit a series of rebrightenings on the decline branch of their light curves. We use visual observations to study this phase in several well-observed novae. We find that these rebrightenings are isolated…
The unprecedented sky coverage and observing cadence of the All-Sky Automated Survey for SuperNovae (ASAS-SN) has resulted in the discovery and continued monitoring of a large sample of Galactic transients. The vast majority of these are…
Recurrent Novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated by ejected material slamming into the companion star's wind,…
The oblique geometry of pulsar wind termination shock ensures that the Doppler beaming has a strong impact on the shock emission. We illustrate this using recent relativistic MHD simulations of the Crab Nebula and also show that the…
The termination regions of non-relativistic jets in protostars and supersonic outflows in classical novae are nonthermal emitters. Given the high densities in these systems, radiative shocks are expected to form. However, in the presence of…
The super-soft source (SSS) phase of a nova eruption, observed a few days after the outburst, usually displays an absorbed X-ray thermal continuum with absorption features, emitted by the white dwarf (WD) atmosphere. However, the X-ray…
Using the disc instability model and a simple but physically reasonable model for the X-ray, extreme UV, UV and optical emission of dwarf novae we investigate the time lags observed between the rise to outburst at different wavelengths. We…
Solar flares are currently understood as the explosive release of energy stored in the form of stressed magnetic fields. In many cases, the released energy seems to take the form of large numbers of electrons accelerated to high energies or…
Shocks in astrophysical transients are key sites of particle acceleration. If the shock upstream is optically thick, radiation smoothens the velocity discontinuity at the shock (radiation-mediated shocks). However, in mildly magnetized…
Supersoft X-ray sources (SSSs) are characterized by persistent thermonuclear burning on the surfaces of white dwarfs (WDs).The standard model requires high mass transfer rates of $\sim 10^{-7}\, {\rm M_{\odot}}\,yr^{-1}$ from massive…
A classical nova is a thermonuclear runaway initiated on a white dwarf accreting solar-like material from its stellar companion. Once the white dwarf accretes enough mass, the pressure at the base of the accreted layer reaches a critical…
We investigate numerically the surface flow on the secondary star during outbursts. We use a simple model for the irradiation and the geometry of the secondary star: the irradiation temperature is treated as a free parameter and the…
Early light curves of many core-collapse supernovae (SNe) are thought to be powered by the interaction of the shock wave with optically thick extended material, either a bound envelope or preexplosion ejected circumstellar matter (CSM). We…
Shock waves constitute discontinuities in matter which are relevant in studying the plasma behaviour in astrophysical scenarios and in heavy-ion collision. They can produce conical emission in relativistic collisions and are also thought to…
In many astrophysical transients, outflows drive shocks into the ambient medium, accelerating electrons to non-thermal energy distributions that produce broadband synchrotron emission. At late times, even initially collimated relativistic…