Related papers: Nucleosynthesis in advective disc and outflow: pos…
We examine the composition of matter as it flows away from gamma ray burst accretion disks, in order to determine what sort of nucleosynthesis may occur. Since there is a large flux of neutrinos leaving the surface of the disk, the electron…
Neutrino-driven winds that follow core collapse supernovae were thought to be the site where half of the heavy elements are produced by the r-process. Although recent hydrodynamic simulations show that the conditions in the wind are not…
X-ray obscuration of active galactic nuclei (AGNs) is considered in the context of ionized winds of stratified structure launched from accretion disks. We argue that a Compton-thick layer of a large-scale disk wind can obscure continuum…
We present a model for a super-Eddington accretion disc around a magnetized neutron star taking into account advection of heat and the mass loss by the wind. The model is semi-analytical and predicts radial profiles of all basic physical…
We use a multi-dimensional Monte Carlo code to compute X-ray spectra for a variety of active galactic nucleus (AGN) disk-wind outflow geometries. We focus on the formation of blue-shifted absorption features in the Fe K band and show that…
It has been suggested that strongly magnetised and rapidly rotating protoneutron stars (PNSs) may produce long duration gamma-ray bursts (GRBs) originating from stellar core collapse. We explore the steady-state properties and heavy element…
In recent years a correlation between mass accretion rates onto new-born stars and their proto-planetary disc masses was detected in nearby young star-forming regions. Although such a correlation can be interpreted as due to…
(abridged) We review how the recent increase in X-ray and radio data from black hole and neutron star binaries can be merged together with theoretical advances to give a coherent picture of the physics of the accretion flow in strong…
We investigate nucleosynthesis inside the gamma-ray burst (GRB) accretion disks formed by the Type II collapsars. In these collapsars, the core collapse of massive stars first leads to the formation of a proto-neutron star and a mild…
Accretion disc coronae (ADC) sources are very high inclination neutron star or black hole binaries, where the outer accretion flow blocks a direct view of the central source. The weak observed X-ray emission is instead produced mainly by…
Using a semi-analytical model of the evolution of the Milky Way, we show how secular evolution can create distinct overdensities in the phase space of various properties (e.g. age vs metallicity or abundance ratios vs age) corresponding to…
We take advantage of a long (with a total exposure time of 120 ks) X-ray observation of the unique Galactic microquasar SS 433, carried out with the XMM-Newton space observatory, to search for a fluorescent line of neutral (or weakly…
We investigate accretion disk winds commonly observed in galactic black hole (BH) X-ray binaries (XRB), which manifest as blueshifted absorption features in X-ray spectra. We model these winds as ideal magnetohydrodynamic outflows of hot…
The origin of accretion disc winds remains disputed to date. High inclination, dipping, neutron star Low Mass X-Ray Binaries (LMXBs) provide an excellent testbed to study the launching mechanism of such winds due to being persistently…
In this paper we survey the theory of wind accretion in high mass X-ray binaries hosting a magnetic neutron star and a supergiant companion. We concentrate on the different types of interaction between the inflowing wind matter and the…
The smooth soft X-ray excess seen in many type-1 AGN can be well described by models of absorption in partially ionized material with a large velocity dispersion, often physically interpreted as a radiatively driven accretion disk wind.…
We present results from the major coordinated X-ray observing program on the ULX NGC 1313 X-1 performed in 2017, combining $XMM$-$Newton$, $Chandra$ and $NuSTAR$, focusing on the evolution of the broadband ($\sim$0.3-30.0 keV) continuum…
Accretion discs properties should deviate from standard theory when magnetic pressure exceeds the thermal pressure. To quantify these deviations, we present a systematic study of the dynamical properties of magnetically arrested discs…
The UV-X continuum, the X-ray spectral features, and the variability in these bands provide powerful tools for studying the innermost regions of AGNs from which we gain an insight into the accretion process. In this chapter the discussion…
We calculate the structure and neutron content of neutrino-heated MHD winds driven from the surface of newly-formed magnetars (``proto-magnetars'') and from the midplane of hyper-accreting disks, two of the possible central engines for…