arXiv subjects

B. H. Hong

Publications and source records attributed to B. H. Hong.

3 recordsLinked to original sources

arXiv1999

Possible re-acceleration regions above the inner gap and pulsar gamma-ray emission

We propose that the violent breakdown of the Ruderman-Sutherland type vacuum gap above the pulsar polar cap region may produce copious primary particles and make the charge density above the gap in excess of the Goldreich-Julian density. Such an excess residue of charge density may arise some re-acceleration regions above the gap due to the space-charge-limited flow mechanism. Such re-acceleration regions, if exist, may accelerate particles to carry away more spin-down energy, and may have some implications for pulsar $γ$-ray emission.

astro-ph↗

arXiv1999

GRB: A Signature of Phase Transition to QGP?

It is suggested that the inner energetic engine of Gamma ray burst (GRB) may be the result of the transition of normal hadron to quark-gluon plasma (QGP) in rapidly-rotating and spin-down newborn neutron star. When such a nascent neutron star slows down through dipole electromagnetic and quadruple gravitational radiation, the increasing center density may reach the QCD transition density, i.e., 5-10 nuclear density. Such kind of energy release from the phase transition would be responsible for GRB and its possible beaming effect. The relative dense gaseous environment of GRB location and the iron line observed in the X-ray afterglow support this idea. Some predictions in this model are given. keywords: Gamma-ray Bursts, Supernova, Quark-gluon plasma

astro-ph↗

arXiv1999

Is Coherence Essential to Account for Pulsar Radio Emission?

Based on definitions, two joint-criteria, namely, the optical-thin constraint and the energy budget constraint, are proposed to judge whether the emission nature of radio pulsars is incoherent or obligatory to be coherent. We find that the widely accepted criterion, $kT_B \le ε$, is not a rational criterion to describe the optical-thin condition, even for the simplest case. The energy budget constraint could be released by introducing a certain efficient radiation mechanism (e.g. the inverse Compton scattering, QL98) with emission power of a single particle as high as a critical value $P_{sing,c} \sim 10^{-4}-10^{-3} {erg s}^{-1}$. This in principle poses the possibilities to interpret high luminosities of pulsars in terms of incoherent emission mechanisms, if the optical-thin constraint could be released by certain mechanism as well. Coherence may not be an essential condition to account for pulsar radio emission.

astro-ph↗