Related papers: Gamma rays from Fast Black-Hole Winds
Present knowledge indicates that gamma-ray bursts are linked with massive stars. They will become invaluable probes of the early universe and galaxy formation. In the future, it will be possible to use gamma-ray bursts for two purposes: 1)…
Powerful winds at accretion-disk scales have been observed in the past 20 years in many AGN. These are the so-called ultrafast outflows (UFOs). Outflows are intimately related to mass accretion through the conservation of angular momentum,…
We discuss the high energy neutrino emission from gamma-ray bursts resulting from the earliest generation (`population III') stars forming in the Universe, whose core collapses into a black hole. These gamma-ray bursts are expected to…
High-energy gamma-ray emission from the Galactic plane above ~100 MeV is composed of three main contributions: diffuse emission from cosmic ray interactions in the interstellar medium, emission from extended sources, such as supernova…
Gamma-ray bursts are flashes of high-energy radiation lasting from a fraction of a second to several hours. Military satellites made the first detections of GRBs in the late 1960s. The $\gamma$-ray emission forms from shocks in a…
Inspired by the excess soft X-ray emission recently detected in Green Pea galaxies, we model the soft X-ray emission (0.5 - 2.0 keV) of hot gas from star cluster winds. By combining individual star clusters, we estimate the soft X-ray…
Massive protostars have associated bipolar outflows with velocities of hundreds of km s$^{-1}$. Such outflows can produce strong shocks when interact with the ambient medium leading to regions of non-thermal radio emission. We aim at…
I discuss the empirical properties of diffuse X-ray emitting gas in the halos of both nearby starburst galaxies and normal spiral galaxies, based on high resolution X-ray spectral imaging with the Chandra X-ray Observatory. Diffuse thermal…
We investigate ultra-fast outflows (UFOs) in active galactic nuclei (AGN) as potential sources of ultra-high-energy cosmic rays (UHECRs). We focus on cosmic-ray nuclei, an aspect not explored previously. These large-scale,…
In this contribution I summarize our current knowledge of the nature and significance of starburst-driven galactic winds (``superwinds''). Superwinds are complex multiphase outflows of cool, warm, and hot gas, dust, and magnetized…
Galactic-scale winds are a generic feature of massive galaxies with high star formation rates across a broad range of redshifts. Despite their importance, a detailed physical understanding of what drives these mass-loaded global flows has…
We report the detection of fast (~ 1000 km/s), massive outflows of neutral gas observed -- using the WSRT -- as 21-cm HI absorption against the strong radio continuum of seven radio sources. The neutral outflows occur, in at least somes…
A gamma-ray burst (GRB) releases an amount of energy similar to that of a supernova explosion, which combined with its rapid variability suggests an origin related to neutron stars or black holes. Since these compact stellar remnants form…
Using new ultraviolet (UV) spectra of five background quasars from the Cosmic Origins Spectrograph on the Hubble Space Telescope, we analyze the low-latitude (|b|=20-30 degree) regions of the Fermi Bubbles, the giant gamma-ray emitting…
Feedback from outflows driven by active galactic nuclei (AGN) can affect the distribution and properties of the gaseous halos of galaxies. We study the hydrodynamics and non-thermal emission from the forward outflow shock produced by an…
Gamma-ray bursts with long durations are widely thought to arise from the collapse of massive stars, where the wind environment is unavoidable. It is also believed that $\gamma$-ray bursts come from jets. Considering these two points in…
Recent studies have indicated that the emission of gravitational waves at the merger of two black holes gives a kick to the final black hole. If the supermassive black hole at the center of a disk galaxy is kicked but the velocity is not…
There is strong observational evidence that AGN, Galactic X-ray transients and (probably) $\gamma$-ray bursts are associated with black holes, and that these sources are able to form collimated, ultrarelativistic outflows. There is much…
This paper deals with the cosmic-ray penetration into molecular clouds and with the related gamma--ray emission. High energy cosmic rays interact with the dense gas and produce neutral pions which in turn decay into two gamma rays. This…
We present semi-analytical models of galactic outflows in high redshift galaxies driven by both hot thermal gas and non-thermal cosmic rays. Thermal pressure alone may not sustain a large scale outflow in low mass galaxies (i.e $M\sim…