Results 141 to 150 of about 893,203 (252)

Let There Be Neutrons! Hadronic Photoproduction from a Large Flux of High-energy Photons

The Astrophysical Journal
We propose that neutrons may be generated in high-energy, high-flux photon environments via photo-induced reactions on pre-existing baryons. These photohadronic interactions are expected to occur in astrophysical jets and surrounding material ...
Matthew R. Mumpower, Tsung-Shung H. Lee, Nicole Lloyd-Ronning, Brandon L. Barker, Axel Gross, Samuel Cupp, Jonah M. Miller   +6 more
doaj   +1 more source

Simple scaling laws for astrophysical jets [PDF]

arXiv, 2006
The idea of a unified model for all astrophysical jets has been considered for quite some time. We present here a few scaling laws relevant to all type of astrophysical jets, analogous to those of \citet{sams96} which are widely used for astrophysical black holes.
arxiv  

Hydrodynamic Simulations of Astrophysical Jets [PDF]

Proceedings of XII Multifrequency Behaviour of High Energy Cosmic Sources Workshop — PoS(MULTIF2017), 2018
{We present recent results of our three-dimensional (3-D) simulations of astrophysical jets. These efforts use the the PLUTO code (Mignone \textit{et al. 2007}) run in a highly parallel environment for the hydrodynamic, magneto-hydrodynamic (MHD), relativistic hydrodynamic (RHD), and relativistic, magnetohydrodynamic (RMHD) simulations.
Pieter Meintjes, James H. Beall, Brian van Soelen, David Rose, Michael T. Wolff, Izak van der Westhuizen, Kevin Lind   +6 more
openaire   +1 more source

Thermospheric Orthohelium, He23S $\mathrm{H}\mathrm{e}\left({\mathrm{2}}^{\mathrm{3}}\mathrm{S}\right)$, Variations Associated With a Moderate Storm in February 2023: The NIRAS‐2 Observations at the Kjell Henriksen Observatory (78.1°N, 16.0°E), Svalbard

Space Weather, Volume 23, Issue 5, May 2025.
Abstract This study presents the time variability of metastable orthohelium, He23S $\mathrm{H}\mathrm{e}\left({\mathrm{2}}^{\mathrm{3}}\mathrm{S}\right)$, in the polar region associated with a geomagnetic storm. A data set consisting of continuous observations of He23S $\mathrm{H}\mathrm{e}\left({\mathrm{2}}^{\mathrm{3}}\mathrm{S}\right)$ airglow ...
Takanori Nishiyama, Masato Kagitani, Tikemani Bag, Takuo T. Tsuda, Yuki Iwasa, Yasunobu Ogawa, Fred Sigernes   +6 more
wiley   +1 more source

Jet rotation driven by MHD shocks in helical magnetic fields [PDF]

, 2011
In this paper we present a detailed numerical investigation of the hypothesis that a rotation of astrophysical jets can be caused by magnetohydrodynamic shocks in a helical magnetic field. Shock compression of the helical magnetic field results in a toroidal Lorentz force component which will accelerate the jet material in toroidal direction.
arxiv   +1 more source

Jet-cloud interations and the brightening of the narrow line region in Seyfert galaxies [PDF]

, 1997
We study the kinematical and brightness evolution of emission line clouds in the narrow line region (NLR) of Seyfert galaxies during the passage of a jet.
A. C. Raga, Hartquist T. W., J. L. Gómez, Pedlar A., R. J. R. Williams, Raga A. C., Steffen W., Taylor D., W. Steffen   +8 more
core   +2 more sources

Reconnection Onset in Overstretched Thin Current Sheets: PIC Simulations

Journal of Geophysical Research: Space Physics, Volume 130, Issue 5, May 2025.
Abstract Onset of reconnection in the magnetotail requires its current sheet (CS) to thin down to the thermal ion gyroradius (or thinner) to demagnetize ions (or even electrons) and to provide their Landau dissipation. However, in isotropic plasma models of the tail the ion‐scale CSs inflate too rapidly with the distance from Earth to remain ion‐scale ...
M. I. Sitnov, H. Arnold
wiley   +1 more source

Laboratory evidence of confinement and acceleration of wide-angle flows by toroidal magnetic fields

Communications Physics
Astrophysical jets play crucial roles in star formation and transporting angular momentum away from accretion discs, however, their collimation mechanism is still a subject of much debate due to the limitations of astronomical observational techniques ...
Z. Lei, L. X. Li, Z. H. Zhao, W. Sun, H. H. An, D. W. Yuan, Y. Xie, W. Q. Yuan, S. K. He, L. Cheng, Z. Zhang, J. Y. Zhong, W. Wang, B. Q. Zhu, W. M. Zhou, C. T. Zhou, S. P. Zhu, J. Q. Zhu, X. T. He, B. Qiao   +19 more
doaj   +1 more source

Estimation of the jet inclination angle for the TDE Swift J1644+57 [PDF]

, 2019
An estimate of the jet inclination angle relative to the accreting black hole's spin can be useful to probe the jet triggering mechanism and the disc--jet coupling. A Tidal Disruption Event (TDE) of a star by a supermassive spinning black hole provides an excellent astrophysical laboratory to study the jet direction through the possibility of jet ...
arxiv   +1 more source

Electron Acceleration and Zebra Stripe Formation in Saturn's Radiation Belts

Journal of Geophysical Research: Space Physics, Volume 130, Issue 5, May 2025.
Abstract This study uses the Versatile Electron Radiation Belt code to model Saturn's radiation belt environment, investigating electron acceleration, loss, and transport mechanisms. The simulations consider various physical processes, including convection particularly driven by a Volland‐Stern (VS) electric field, radial diffusion, collisional energy ...
A. Y. Drozdov, P. Kollmann, Y. Hao, D. Wang, E. E. Woodfield   +4 more
wiley   +1 more source