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Supernova shocks into dense molecular cores in IC 443 (clumps B, C, and G) and 3C 391 were observed using the Stratospheric Observatory for Infrared Astronomy and complemented by archival data from the Herschel Space Observatory. The pure…

Astrophysics of Galaxies · Physics 2024-11-07 William T. Reach , Ngoc Le Tram , Curtis DeWitt , Pierre Lesaffre , Benjamin Godard , Antoine Gusdorf

We present the equivalent width and column density measurements for low and intermediate ionization states of the circumgalactic medium (CGM) surrounding 44 low-z, L ~ L* galaxies drawn from the COS-Halos survey. These measurements are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jessica Werk , J. Xavier Prochaska , Christopher Thom , Jason Tumlinson , Todd Tripp , John O'Meara , Molly Peeples

Shocks are ubiquitous in the interstellar and intergalactic media, where their chemical and radiative signatures reveal the physical conditions in which they arise. Detailed astrochemical models of shocks at all velocities are necessary to…

Astrophysics of Galaxies · Physics 2020-11-11 A. Lehmann , B. Godard , G. Pineau des Forêts , E. Falgarone

Aims. The goal of the paper is to present a detailed study of the propagation of low velocity (5 to 25 km s-1) stationary molecular shocks in environments illuminated by an external ultraviolet (UV) radiation field. In particular, we intend…

We investigate chemistry in the compression layer behind the interstellar shock waves, where molecular cloud formation starts. We perform three-dimensional magnetohydrodynamics simulations of converging flows of atomic gas with shock…

Astrophysics of Galaxies · Physics 2024-11-20 Yuto Komichi , Yuri Aikawa , Kazunari Iwasaki , Kenji Furuya

We study the acceleration of heavy nuclei at SNR shocks when the process of ionization is taken into account. Heavy atoms ($Z_N >$ few) in the interstellar medium which start the diffusive shock acceleration (DSA) are never fully ionized at…

High Energy Astrophysical Phenomena · Physics 2011-04-05 Giovanni Morlino

Radiative shocks (also called supercritical shocks) are high Mach number shock waves that photoionize the medium ahead of the shock front and give rise to a radiative precursor. They are generated in the laboratory using high-energy or…

Accumulating observational evidence for a number of radio galaxies suggests an association between their jets and regions of active star formation. The standard picture is that shocks generated by the jet propagate through an inhomogeneous…

Astrophysics · Physics 2009-11-10 P. Chris Fragile , Stephen D. Murray , Peter Anninos , Wil van Breugel

We present a grid of nonequilibrium ionization models for the X-ray spectra from supernova remnants undergoing efficient diffusive shock acceleration. The calculation follows the hydrodynamics of the blast wave as well as the time-dependent…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Daniel J. Patnaude , Patrick Slane , John C. Raymond , Donald C. Ellison

We use a set of cosmological simulations combined with radiative transfer calculations to investigate the distribution of neutral hydrogen in the post-reionization Universe. We assess the contributions from the metagalactic ionizing…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-27 Alireza Rahmati , Andreas H. Pawlik , Milan Raičević , Joop Schaye

Motivated by recent observations with Herschel/PACS, and the availability of new rate coefficients for the collisional excitation of CO (Yang et al. 2010), the excitation of warm astrophysical CO is revisited with the use of numerical and…

Astrophysics of Galaxies · Physics 2015-06-04 David A. Neufeld

The nonthermal source abundances of elements play a crucial role in the understanding of cosmic ray (CR) phenomena from a few GeV up to several tens of EeV. We present a first systematic approach to describe the change of the abundances…

High Energy Astrophysical Phenomena · Physics 2021-02-03 Björn Eichmann , Jörg P. Rachen

This work provides analytical solutions describing the post-shock structure of radiative shocks growing in astrophysics and in laboratory. The equations including a cooling function $\Lambda \propto \rho^{\epsilon} P^{\zeta} x^{\theta}$ are…

Using the LCLS facility at the SLAC National Accelerator Laboratory, we have observed X-ray scattering from iron compressed with laser driven shocks to Earth-core like pressures above 400GPa. The data shows shots where melting is incomplete…

We have studied the effect of time-dependent ionization and recombination processes on magnetic reconnection in the solar corona. Petschek-type steady reconnection, in which model the magnetic energy is mainly converted at the slow-mode…

Solar and Stellar Astrophysics · Physics 2015-05-30 S. Imada , I. Murakami , T. Watanabe , H. Hara , T. Shimizu

Our aim is to determine the dominant processes and timescales for the ionisation equilibrium of calcium under solar chromospheric conditions. The study is based on numerical simulations with the RADYN code, which includes hydrodynamics,…

Solar and Stellar Astrophysics · Physics 2015-05-27 Sven Wedemeyer-Böhm , Mats Carlsson

We present ion-by-ion cooling efficiencies for low-density gas. We use Cloudy (ver. 08.00) to estimate the cooling efficiencies for each ion of the first 30 elements (H-Zn) individually. We present results for gas temperatures between 1e4…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Orly Gnat , Gary J. Ferland

Non-relativistic collisionless shock waves are widespread in space and astrophysical plasmas and are known as efficient particle accelerators. However, our understanding of collisionless shocks, including their structure and the mechanisms…

Plasma Physics · Physics 2015-07-23 T. Liseykina , G. Dudnikova , V. Vshivkov , M. Malkov

The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we…

Instrumentation and Methods for Astrophysics · Physics 2017-04-10 Jeffrey G. Mangum , Yancy L. Shirley

We investigate the interaction of nonthermal ions (protons and nuclei) accelerated in an ultrarelativistic blastwave with the pre-existing magnetic field of the medium into which the blastwave propagates. While particle acceleration…

Astrophysics · Physics 2009-11-13 Sean M. Couch , Milos Milosavljevic , Ehud Nakar
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