Related papers: Ultra Fast Self-Compton Cooling
The hard X-ray spectra of accreting black holes systems are generally well-fit by thermal Comptonization models with temperatures $\sim 100$ keV. We demonstrate why, over many orders of magnitude in heating rate and seed photon supply, hot…
We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from…
Ultrafast electron dynamics of solids after an absorption of femtosecond laser pulse is governed by electron-electron, electron-phonon, phonon-electron, and phonon-phonon collisions. It is of importance to construct a framework for…
Active galactic nuclei (AGN) drive fast winds in the interstellar medium of their host galaxies. It is commonly assumed that the high ambient densities and intense radiation fields in galactic nuclei imply short cooling times, thus making…
We propose a method to cool a thermal photonic state in a cavity by passing electrons through it. Electrons are coherently split into two paths, with one path traversing the cavity, becoming entangled with its photonic state. A sequence of…
We present preliminary results of our work on blazar unification. We assume that all blazars have a broad line region (BLR) and that the size of the BLR scales with the power of the source in a manner similar to that derived through…
The backward Compton scattering is a basic process at future higher energy photon colliders. To obtain a high probability of e->gamma conversion the density of laser photons in the conversion region should be so high that simultaneous…
Long lifetimes of hot carriers can lead to qualitatively new types of responses in materials. The magnitude and time scales for these responses reflect the mechanisms governing energy flows. We examine the microscopics of two processes…
Laser-induced nonthermal melting in semiconductors has been studied over the last four decades, but the underlying mechanism is still under debate. Here, by utilizing an advanced real-time time-dependent density functional theory…
Compression of UV femtosecond laser pulses focused into a gas cell filled with xenon is reported numerically. With a large negative Kerr index and normal dispersion, xenon promotes temporal modulational instability (MI) which can be…
We report the cooling of an atomic ensemble with light, where each atom scatters only a single photon on average. This is a general method that does not require a cycling transition and can be applied to atoms or molecules which are…
We propose an alternative method to laser cooling. Our approach utilizes the extreme brightness of a supersonic atomic beam, and the adiabatic atomic coilgun to slow atoms in the beam or to bring them to rest. We show how internal-state…
We propose a new laser cooling method for atomic species whose level structure makes traditional laser cooling difficult. For instance, laser cooling of hydrogen requires vacuum-ultraviolet laser light, while multielectron atoms need laser…
We perform a femtosecond-THz optical pump-probe spectroscopy to investigate the cooling dynamics of hot carriers in quasi-free standing bilayer epitaxial graphene. We observed longer decay time constants, in the range of 2.6 to 6.4 ps,…
We propose a laser cooling technique in which atoms are selectively excited to a dressed metastable state whose light shift and decay rate are spatially correlated for Sisyphus cooling. The case of cooling magnetically trapped…
With today's multi-petawatt lasers, testing quantum electrodynamics (QED) in the strong field regime, where the electric field exceeds the Schwinger critical field in the rest frame of an electron, becomes within reach. Inverse Compton…
We use Monte Carlo approach to study the energetics of electrons accelerated in a pulsar polar gap. As energy-loss mechanisms we consider magnetic Compton scattering of thermal X-ray photons and curvature radiation. The results are compared…
Recent experiments with ultracold neutral plasmas show an intrinsic heating effect based on the development of spatial correlations. We investigate whether this effect can be reversed, so that imposing strong spatial correlations could in…
We use hydrodynamic simulations with adaptive grid refinement to study the dependence of hot gas flows in X-ray luminous giant elliptical galaxies on the efficiency of heat supply to the gas. We consider a number of potential heating…
Electrons in shocks are efficiently energized due to the cross-shock potential, which develops because of differential deflection of electrons and ions by the magnetic field in the shock front. The electron energization is necessarily…