Essays about: "black hole accretion"

Showing result 1 - 5 of 11 essays containing the words black hole accretion.

1. 1. Black Holes of the First Stars

   University essay from Uppsala universitet/Institutionen för fysik och astronomi

   Author : Aron Kordt; [2022]
   Keywords : ;

   Abstract : In this report, we constrain properties of foreground objects in the Milky Way that have the potential of being confused with accretion disks of Population III stellar- mass black holes at high redshift. Following Windhorst et al. (2018), a model for multicolour accretion disks of Population III stellar-mass black holes is presented. READ MORE

3. 2. Superradiant axion clouds and their interaction with astrophysical plasma

   University essay from KTH/Fysik

   Author : Erik Engstedt; [2021]
   Keywords : axions; superradiance; black holes; black hole accretion; astrophysical plasma; axioner; strålningsförstärkning; svarta hål; svart hålansamling; astrofysikalisk plasma;

   Abstract : Axions are one of the best-motivated particles beyond the standard model of particle physics and a promising candidate for dark matter. Through the superradiant instability, axions can extract a significant amount of rotational energy from spinning black holes resulting in dense axion clouds. READ MORE

4. 3. Lyman Continuum Radiation from Intermediate-Mass Black Holes : An Estimation of the Contribution of LyC Radiation from IMBHs in z~3 Galaxies

   University essay from Uppsala universitet/Observationell astrofysik

   Author : Marika Ljungberg; [2020]
   Keywords : intermediate-mass black holes; cosmic reionization; high-redshift galaxies;

   Abstract : This thesis concerns the cosmic reionization of the intergalactic medium in the high redshift universe and, in particular, is a first approach to examine what role intermediate mass black holes (IMBHs) play in this cosmic age. Unexpectedly high values of hydrogen ionizing radiation, compared to current models, have been reported from galaxies at redshift ~3 (used as stand-ins for galaxies at the age of reionization), and thus these models need revision, potentially by adding effects of IMBH content in the galaxies. READ MORE

5. 4. Original: X-ray Spectral Analysis of a Serendipitously Observed Active Galactic Nucleus

   University essay from KTH/Skolan för teknikvetenskap (SCI)

   Author : Teodor Elmfeldt; Filip af Malmborg; [2020]
   Keywords : ;

   Abstract : An active galactic nucleus (AGN) is a region in the center of a galaxy with a supermassive black hole continuosly accreting material. This accretion gives rise to large amounts of radiation across the whole electromagnetic spectrum, and largely affects the regions around the AGN and the evolution of the whole galaxy. READ MORE

6. 5. Ultraluminous sources in X-ray sky surveys

   University essay from Uppsala universitet/Högenergifysik

   Author : Miquel Colom i Bernadich; [2020]
   Keywords : X-rays; X-ray astronomy; black holes; neutron stars; accretion physics; XMM-Newton; eROSITA;

   Abstract : Ultraluminous X-ray sources (ULXs) are extragalactic, non-nuclear, point-like X-ray sources whose luminosity supersedes that of the Eddington limit of an accreting stellar mass black hole (L> 10 ^ 39 erg / s). Most of them are powered by black holes and neutron stars undergoing genuine super-Eddington accretion, with a small handful of candidates being consistent with sub-Eddington accretion on an intermediate mass black hole. READ MORE