arXiv subjects

Uicheol Jang

Publications and source records attributed to Uicheol Jang.

4 recordsLinked to original sources

arXiv2023

The Bardeen-Petterson Effect as an Observable Support for the Blanford-Payne Process Black Hole Jet Production

Relativistic jets are observed around accreting black holes, from stellar mass to super massive black holes. But Its origin has not been fully understood. Although Blanford-Payne process has been considered as most reliable theory of jet production It has no observational proof or supports. In this problem, We suggested the way to display that Bardeen-Petterson effect can become a supporter as providing observational idea of Blanford-Payne process. And we studied black hole jet production by Blanford-Payne process and Bardeen-Peterson effect. As a result, we could calculate observable timescale of black hole jet preccetion

astro-ph.HE↗

arXiv2023

Inclusion of the effect of radiation pressure on the accretion phenomena in astrophysics

Studying accretion phenomena is a window into understanding most heavenly bodies, from the birth of stars to Active galactic nuclei(AGN). We would adopt the effect of the radiation pressure which reduces accretion rates M on the accretion phenomena. Shakura-Sunyaev$α$-disk model of disk accretion can be regarded as a good candidate theory of ADAF. Reduction of accreting matter's angular velocity leads to the suppression of the disk luminosity and the surface temperature which essentially implies the transition of the standard accretion disk model from CDAF to ADAF.

astro-ph.GA↗

arXiv2021

Thick accretion disk and Its super Eddington luminosity around spinning blackholes

In the general accretion disk model theory, the accretion disk surrounding an astronomical object comprises fluid rings obeying Keplerian motion. However, we should consider relativistic and rotational effects as we close in toward the center of accretion disk surrounding spinning compact massive objects such as a black hole or a neutron star. In this study, we explore the geometry of the inner portion of the accretion disk in the context of Mukhopadhyay's pseudo Newtonian potential approximation for the full general relativity theory. We found that the shape of the accretion disk "puffs up" or becomes thicker and the luminosity of the disk could exceed the Eddington luminosity near the surface of the compact spinning black hole.

astro-ph.HE↗

arXiv2020

Toward practical/realistic Randall-Sundrum Brane world scenario

The Randall- Sundrum brane world scenario is mostly preserved and still secure as we realized that the graviton trap is still safely guaranteed. We would like to empathize here that such necessary but rich elaboration doesn't cost a fortune as the Ricci flatness condition effectively accommodates the realistic structure of our universe on the one hand, while still sustaining the 4-dimensional graviton trap on the other.

gr-qc↗