Sökning: "AGN"

Visar resultat 1 - 5 av 18 avhandlingar innehållade ordet AGN.

1. 1. Seeking the faint extremes : Detection and characterisation of extragalactic soft-spectrum gamma-ray sources and exploring methods to enhance their detection with machine learning in the 50 GeV-50 TeV energy range

   Författare :Tomas Bylund; Yvonne Becherini; Gilles Henri; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; GeV gamma-rays; TeV gamma-rays; AGN; blazar; deep learning; observational high-energy astronomy; Astroparticle Physics; Astropartikelfysik;

   Sammanfattning : This thesis deals with an observational study of Blazars, strong gamma-ray sources with Very High Energies (VHE) located far outside our Galaxy. Blazars are a class of galaxies that contain a supermassive black hole that is actively consuming large quantities of matter, a process that results in the liberation of tremendous amounts of energy that then powers the emission of huge bulks of charged particles that get accelerated almost to the speed of light. LÄS MER

3. 2. The environment of high-redshift AGN

   Författare :Judit Fogasy; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : In order to understand the formation and evolution of local massive galaxies and to reveal the processes that engineered the tight correlations found between their supermassive black hole (SMBH) mass and bulge mass or velocity dispersion, the study of powerful, high-redshift active galactic nuclei (AGN) and their environment is crucial. Observations of high-z quasars and radio galaxies suggest that these AGN live in overdense environment surrounding by star-forming Ly&alpha-emitters and submillimeter galaxies. LÄS MER

4. 3. Active Galactic Nuclei in galaxy surveys : Empirical paths to the fiery hearts of cosmic beasts

   Författare :Beatriz Villarroel; Andreas J. Korn; Takis Konstantopoulos; Moshe Elitzur; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomi;

   Sammanfattning : Some galaxies emit excessive amounts of light from their centers, caused by accretion of gas onto super-massive black holes (SMBH). These galactic cores are often referred to as Active Galactic Nuclei (AGN) and they come in many different forms, distinguishable by their emission properties. LÄS MER

5. 4. A High Resolution Study of the LINER Galaxy NGC5218

   Författare :Evert Olsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Low Ionisation Nuclear Emission-line Regions (LINERs)are found in one third of the galaxies in the local bright galaxy population. The LINERs typically recide in the central parts of their host galaxies, and occur in early type elliptical galaxies as well as late type spiral galaxies. LÄS MER

7. 5. High-redshift active galactic nuclei and their environment

   Författare :Judit Fogasy; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; galaxies: evolution -- galaxies: high-redshift -- galaxies: active -- galaxies: Starburst -- -- Submillimeter: galaxies;

   Sammanfattning : In order to understand the formation and evolution of local massive galaxies and to reveal the processes that engineered the tight correlations found between their supermassive black hole (SMBH) mass and bulge mass or velocity dispersion, the study of powerful, high-redshift active galactic nuclei (AGNs) and their environment is crucial. AGNs are luminous targets providing important clues to galaxy evolution, as their central SMBH is growing at high rates, which opens the opportunity to unfold how the growth of the black hole influences the growth of its host galaxy. LÄS MER