Active galactic nuclei (AGN)
|
|
- Juniper Fields
- 5 years ago
- Views:
Transcription
1 Active galactic nuclei (AGN) General characteristics and types Supermassive blackholes (SMBHs) Accretion disks around SMBHs X-ray emission processes Jets and their interaction with ambient medium Radio galaxies Based partly on the lectures by I. M. Gorege (GSFC) and Liz Puchnarewicz (MSSL)
2 Why are AGNs interesting? AGN are the most luminous steady sources of radiation in the universe, and the most compact They allow us to study matter very close to black holes and the black holes themselves They are observed out to enormous distances (redshifts) and therefore can be used as cosmological probes in several ways SMBHs are present in essentially all galaxies, and the formation and evolution of the black hole is related to the formation of the galaxy
3 AGNs: accreting SMBHs Apparently stellar (< 1 pc). Very luminous ( erg/s, ~ x the luminosity of a typical galaxy); ergs/s corresponds to 2 M sun /year. Eddington limit implies mass M>8 x 10 5 M sun Primarily non-thermal spectra extend over a broad range (sometimes 13 orders of magnitudes in energy. Radiation is not powered primarily by star light, which is typically confined within a decade of photon energy Line emission in optical and UV may account for a few to a few tens % of the total lum, sometimes, indicating bulk velocities up to 10 4 km/s Variation at a level of ~10% on time scales of few years, higher (a factor of 2 variation) in X-rays. Dynamical studies show masses of ~ M sun
4 Quasars Basic types of AGNs Point like ( quasi-stellar ) on photographic plates, outshining its host galaxy Emit 5-8 orders of magnitude more than normal galaxies Seyferts Peculiar, broad, high ionization emission lines in the optical Nuclear emission exceeds normal galaxy by 1-5 orders of magnitude Make up about 1% of all galaxies usually found in spiral galaxies LINERS (low-ionization nuclear emission-line regions) About 10% of all galaxies show some kind of evidence for activity (point-like nuclei, strong emission lines, etc.) though not necessarily dominant
5
6 Quasars This animation takes you on a tour of a quasar from beyond the galaxy, right up to the edge of the black hole. It covers ten orders of magnitude, ie the last frame covers a distance 10 billion times smaller than the first. Animation of a quasar
7 AGN Accretion Believed to be powered by accretion onto SMBHs high luminosities highly variable Eddington limit => large mass Accretion onto SMBH small source size
8 SMBHs and AGNs The gas and dust in this disk are swirling into what is almost certainly a massive black hole. Origin of the disk material: interstellar gas infalling stars remnant of gas cloud which originally formed black hole The Heart Of NGC 4261
9 High energy spectrum of AGN Spectrum from the optical to medium X-rays Log ν*fν Low-energy disk tail Balmer cont, FeII lines high-energy disk tail Comptonized disk optical UV EUV soft X-rays X-rays Log ν
10 X-ray Emission The accretion disk is not hot enough to give off X- rays, even in the innermost regions Assuming black-body emission, L ~ 2 πr in2 σ T in 4 L =f L edd = f 4πcGMm/σ T r in ~ 3R s = 6GM/c 2 Therefore, T in ~ (1.4x10 5 K) (f 10 8 M sun /M) 1/4 X-rays are observed out to at least 100 kev in many objects, which implies temperatures of 10 9 K, Requires additional radiation mechanism AND an additional method of generating energy (dissipation) This X-ray source is often referred as a corona
11 Gorege and Fabian 1991 corona bulge UV optical
12 Photon reflection: Fe Kα line X-ray e- Fe Kα Photon absorption Compton scattering Absorption followed by fluorescence line emission Line centroid and width provide fiducial energy marker Strong and isolated line from other features Line emission originating close to the black hole (~<10 R s ), giving information about non-newtonian gravity G.R. effect
13 Radio sources Only few % of galaxies contain AGN At low luminosities => radio galaxies Radio galaxies have powerful radio emission - usually found in ellipticals Radio galaxies erg/s Quasars erg/s
14 Jets from AGNs Black hole surrounded by accretion disk further feeds jets, which are formed perpendicular to the disk, perhaps confined by magnetic field X-Ray Jet From Centaurus A Artist s impression
15 Jets and Lobes jet lobe AGN IGM energy carried out along channels Synchrotron lifetimes in the lobes are short compared to extent of jets => additional acceleration required. Most jet energy is ordered kinetic energy. Gas flow in jet is supersonic and is reverseshocked at hot spot. Energy now in relativistic particles and mag field. hot spot
16 Particle energy spectrum Assuming particle injection spectrum 2 n/ γ t=n 0 γ -x, what would be the steady state particle energy spectrum? Particle radiation is energy-dependent change of energy spectral shape. For synchrotron or I.C, dγ/dt = βγ 2 Conservation law for particles in the γ-t space N/ t+ [(dγ/dt)n(γ)]/ γ=n 0 γ -x For a steady state, N/ t=0, N(γ)= n 0 /[β(x-1)] γ -x-1 But this solution may not apply to low energy particles whose synchrotron lifetime is longer than that of the system.
17 More general solution (evolution) For particles injected at time t 0, dγ/dt = βγ 2 -> γ=γ 0 /[1+γ 0 β(t- t 0 )], or γ 0 =γ/[1-γβ(t- t 0 )]. For γ 0 > 0, t 0 > t- 1/(γβ). So if 2 n/ t 0 γ 0 γ -x 0, N 2 n/ t 0 γ ( 2 n/ t 0 γ 0 )( γ 0 / γ) γ -x 0 γ -x [1-γβ(t- t 0 )] x-2 γ -x N(γ)= 2 n/ t 0 γ dt 0 For γ < 1/(tβ), integration from 0 to t -> N γ -x-1 [1-(1-γβt) x-1 ] γ -x if γtβ 0 γ -x-1 For γ > 1/(tβ), integration from t-1/(γβ) to t γ -> N γ -x-1 The break of the spectrum can be used to estimate the age of the electrons emitting the radiation.
18 Equipartition of energy Assuming a radio synchrotron source with a luminosity L and the energy distribution N(E) E -p The synchrotron emission F ν ν -(p-1)/2 Particle energy content of the source U e ~ t sync (ν b ) L ~ (1.5 x erg) B -3/2 ν b -1/2 L where t sync (ν b ) ~ (7 x 10 2 sec) B -2 E b -1 is the synchrotron life time of the particle with the characteristic energy E b ~ (5 x erg) B -1/2 ν b 1/2 at the spectral break. Total energy U=(1+k)U e +U mag where 1 < k (=U p /U e ) < 2000 and U mag = VB 2 /4π du/db =0 => the minimum energy U mag =¾(1+k) U e U mag ~ U e if k ~ 1 equipartition!
19 Example: Cygnus A Observed luminosity ~ 5x10 44 erg/s Frequency break observed is Hz γ~10 5 -> t syn ~ 3x10 3 yrs magnetic field, B ~ 5x10-5 Gauss minimum energy requirement ~ erg This implies a source lifetime ~ 10 7 years Thus electron acceleration is required in the lobes.
20 Relativistic Beaming Small-scale morphology probed by VLBI Most cases - only one jet is observed Two phenomena are at work in these cases: 1. Superluminal expansion 2. Relativistic beaming Plasma appears to radiate preferentially along its direction of motion. Thus observer sees only jet pointing towards her - other jet is invisible. AGN Photons emitted in a cone of radiation and Doppler boosted towards observer.
21 Some outstanding problems What is the correct unification model? Radio quiet/loud and Seyfert 1 and 2. What is the physical structure of the accretion disk? What is the origin of the viscosity in the disk? What is the origin of the high energy emission and where is it produced? What is the origin of the rapid X-ray variability Can we get accurate measurements of the black hole mass? Is the black hole spinning? What is the connection between AGN and normal galaxies? How do AGN evolve with cosmic time?
Galaxies with Active Nuclei. Active Galactic Nuclei Seyfert Galaxies Radio Galaxies Quasars Supermassive Black Holes
Galaxies with Active Nuclei Active Galactic Nuclei Seyfert Galaxies Radio Galaxies Quasars Supermassive Black Holes Active Galactic Nuclei About 20 25% of galaxies do not fit well into Hubble categories
More informationActive Galactic Nuclei
Active Galactic Nuclei Optical spectra, distance, line width Varieties of AGN and unified scheme Variability and lifetime Black hole mass and growth Geometry: disk, BLR, NLR Reverberation mapping Jets
More informationAstr 2320 Thurs. April 27, 2017 Today s Topics. Chapter 21: Active Galaxies and Quasars
Astr 2320 Thurs. April 27, 2017 Today s Topics Chapter 21: Active Galaxies and Quasars Emission Mechanisms Synchrotron Radiation Starburst Galaxies Active Galactic Nuclei Seyfert Galaxies BL Lac Galaxies
More informationChapter 17. Active Galaxies and Supermassive Black Holes
Chapter 17 Active Galaxies and Supermassive Black Holes Guidepost In the last few chapters, you have explored our own and other galaxies, and you are ready to stretch your scientific imagination and study
More informationLecture 9. Quasars, Active Galaxies and AGN
Lecture 9 Quasars, Active Galaxies and AGN Quasars look like stars but have huge redshifts. object with a spectrum much like a dim star highly red-shifted enormous recessional velocity huge distance (Hubble
More informationAccretion Disks. 1. Accretion Efficiency. 2. Eddington Luminosity. 3. Bondi-Hoyle Accretion. 4. Temperature profile and spectrum of accretion disk
Accretion Disks Accretion Disks 1. Accretion Efficiency 2. Eddington Luminosity 3. Bondi-Hoyle Accretion 4. Temperature profile and spectrum of accretion disk 5. Spectra of AGN 5.1 Continuum 5.2 Line Emission
More informationLecture Outlines. Chapter 24. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc.
Lecture Outlines Chapter 24 Astronomy Today 8th Edition Chaisson/McMillan Chapter 24 Galaxies Units of Chapter 24 24.1 Hubble s Galaxy Classification 24.2 The Distribution of Galaxies in Space 24.3 Hubble
More informationQuasars and AGN. What are quasars and how do they differ from galaxies? What powers AGN s. Jets and outflows from QSOs and AGNs
Goals: Quasars and AGN What are quasars and how do they differ from galaxies? What powers AGN s. Jets and outflows from QSOs and AGNs Discovery of Quasars Radio Observations of the Sky Reber (an amateur
More informationChapter 15 2/19/2014. Lecture Outline Hubble s Galaxy Classification. Normal and Active Galaxies Hubble s Galaxy Classification
Lecture Outline Chapter 15 Normal and Active Galaxies Spiral galaxies are classified according to the size of their central bulge. Chapter 15 Normal and Active Galaxies Type Sa has the largest central
More informationQuasars ASTR 2120 Sarazin. Quintuple Gravitational Lens Quasar
Quasars ASTR 2120 Sarazin Quintuple Gravitational Lens Quasar Quasars Quasar = Quasi-stellar (radio) source Optical: faint, blue, star-like objects Radio: point radio sources, faint blue star-like optical
More informationActive Galactic Nuclei
Active Galactic Nuclei Prof. Jeff Kenney Class 18 June 20, 2018 the first quasar discovered 3C273 (1963) very bright point source (the quasar ) jet the first quasar discovered 3C273 (1963) very bright
More informationX-ray data analysis. Andrea Marinucci. Università degli Studi Roma Tre
X-ray data analysis Andrea Marinucci Università degli Studi Roma Tre marinucci@fis.uniroma3.it Goal of these lectures X-ray data analysis why? what? how? Why? Active Galactic Nuclei (AGN) Physics in a
More informationActive Galactic Nuclei
Active Galactic Nuclei How were they discovered? How common are they? How do we know they are giant black holes? What are their distinctive properties? Active Galactic Nuclei for most galaxies the luminosity
More informationBlack Holes and Active Galactic Nuclei
Black Holes and Active Galactic Nuclei A black hole is a region of spacetime from which gravity prevents anything, including light, from escaping. The theory of general relativity predicts that a sufficiently
More informationActive Galactic Nuclei OIII
Active Galactic Nuclei In 1908, Edward Fath (1880-1959) observed NGC 1068 with his spectroscope, which displayed odd (and very strong) emission lines. In 1926 Hubble recorded emission lines of this and
More informationHigh-Energy Astrophysics Lecture 6: Black holes in galaxies and the fundamentals of accretion. Overview
High-Energy Astrophysics Lecture 6: Black holes in galaxies and the fundamentals of accretion Robert Laing Overview Evidence for black holes in galaxies and techniques for estimating their mass Simple
More informationPowering Active Galaxies
Powering Active Galaxies Relativity and Astrophysics ecture 35 Terry Herter Bonus lecture Outline Active Galaxies uminosities & Numbers Descriptions Seyfert Radio Quasars Powering AGN with Black Holes
More informationGalaxies. Galaxy Diversity. Galaxies, AGN and Quasars. Physics 113 Goderya
Galaxies, AGN and Quasars Physics 113 Goderya Chapter(s): 16 and 17 Learning Outcomes: Galaxies Star systems like our Milky Way Contain a few thousand to tens of billions of stars. Large variety of shapes
More informationActive Galactic Nuclei - Zoology
Active Galactic Nuclei - Zoology Normal galaxy Radio galaxy Seyfert galaxy Quasar Blazar Example Milky Way M87, Cygnus A NGC 4151 3C273 BL Lac, 3C279 Galaxy Type spiral elliptical, lenticular spiral irregular
More informationActive Galaxies & Quasars
Active Galaxies & Quasars Normal Galaxy Active Galaxy Galactic Nuclei Bright Active Galaxy NGC 5548 Galaxy Nucleus: Exact center of a galaxy and its immediate surroundings. If a spiral galaxy, it is the
More informationA zoo of transient sources. (c)2017 van Putten 1
A zoo of transient sources (c)2017 van Putten 1 First transient @ first light UDFj-39546284, z~10.3 Bouwens, R.J., et al., Nature, 469, 504 Cuchiara, A. et al., 2011, ApJ, 736, 7 z=9.4: GRB 090429B, z~9.4
More informationQuasars and Active Galactic Nuclei (AGN)
Quasars and Active Galactic Nuclei (AGN) Astronomy Summer School in Mongolia National University of Mongolia, Ulaanbaatar July 21-26, 2008 Kaz Sekiguchi Hubble Classification M94-Sa M81-Sb M101-Sc M87-E0
More informationActive galaxies. Some History Classification scheme Building blocks Some important results
Active galaxies Some History Classification scheme Building blocks Some important results p. 1 Litirature: Peter Schneider, Extragalactic astronomy and cosmology: an introduction p. 175-176, 5.1.1, 5.1.2,
More informationA100H Exploring the Universe: Quasars, Dark Matter, Dark Energy. Martin D. Weinberg UMass Astronomy
A100H Exploring the :, Dark Matter, Dark Energy Martin D. Weinberg UMass Astronomy astron100h-mdw@courses.umass.edu April 19, 2016 Read: Chaps 20, 21 04/19/16 slide 1 BH in Final Exam: Friday 29 Apr at
More informationStar systems like our Milky Way. Galaxies
Galaxies Star systems like our Milky Way Galaxies Contain a few thousand to tens of billions of stars,as well as varying amounts of gas and dust Large variety of shapes and sizes Gas and Dust in
More informationActive Galaxies. Lecture Topics. Lecture 24. Active Galaxies. Potential exam topics. What powers these things? Lec. 24: Active Galaxies
Active Galaxies Lecture 24 APOD: M82 (The Cigar Galaxy) 1 Lecture Topics Active Galaxies What powers these things? Potential exam topics 2 24-1 Active Galaxies Galaxies Luminosity (L MW *) Normal < 10
More informationThe X-Ray Universe. The X-Ray Universe
The X-Ray Universe The X-Ray Universe Potsdam University Dr. Lidia Oskinova Sommersemester 2017 lida@astro.physik.uni-potsdam.de astro.physik.uni-potsdam.de ~lida/vorlesungxrayso17.html Chandra X-ray,
More informationGRB history. Discovered 1967 Vela satellites. classified! Published 1973! Ruderman 1974 Texas: More theories than bursts!
Discovered 1967 Vela satellites classified! Published 1973! GRB history Ruderman 1974 Texas: More theories than bursts! Burst diversity E peak ~ 300 kev Non-thermal spectrum In some thermal contrib. Short
More informationActive Galactic Nuclei (AGNs): A type of AGNs: Quasars. Whatever is powering these QSO s must be very small!!
Active Galactic Nuclei (AGNs): Galaxies with lots of activity AST 101 General Astronomy: Stars & Galaxies Some galaxies at high redshift (large lookback times) have extremely active centers More than 1000
More informationGuiding Questions. Active Galaxies. Quasars look like stars but have huge redshifts
Guiding Questions Active Galaxies 1. Why are quasars unusual? How did astronomers discover that they are extraordinarily distant and luminous? 2. What evidence showed a link between quasars and galaxies?
More informationIntroduction to AGN. General Characteristics History Components of AGN The AGN Zoo
Introduction to AGN General Characteristics History Components of AGN The AGN Zoo 1 AGN What are they? Active galactic nucleus compact object in the gravitational center of a galaxy that shows evidence
More informationActive Galaxies and Quasars
Active Galaxies and Quasars Radio Astronomy Grote Reber, a radio engineer and ham radio enthusiast, built the first true radio telescope in 1936 in his backyard. By 1944 he had detected strong radio emissions
More informationVera Genten. AGN (Active Galactic Nuclei)
Vera Genten AGN (Active Galactic Nuclei) Topics 1)General properties 2)Model 3)Different AGN-types I. Quasars II.Seyfert-galaxies III.Radio galaxies IV.young radio-loud AGN (GPS, CSS and CFS) V.Blazars
More informationAstrophysical Quantities
Astr 8300 Resources Web page: http://www.astro.gsu.edu/~crenshaw/astr8300.html Electronic papers: http://adsabs.harvard.edu/abstract_service.html (ApJ, AJ, MNRAS, A&A, PASP, ARAA, etc.) General astronomy-type
More informationOther Galaxy Types. Active Galaxies. A diagram of an active galaxy, showing the primary components. Active Galaxies
Other Galaxy Types Active Galaxies Active Galaxies Seyfert galaxies Radio galaxies Quasars Origin??? Different in appearance Produce huge amount of energy Similar mechanism a Galactic mass black hole at
More informationAST Cosmology and extragalactic astronomy. Lecture 20. Black Holes Part II
AST4320 - Cosmology and extragalactic astronomy Lecture 20 Black Holes Part II 1 AST4320 - Cosmology and extragalactic astronomy Outline: Black Holes Part II Gas accretion disks around black holes, and
More informationHigh-Energy Astrophysics Lecture 1: introduction and overview; synchrotron radiation. Timetable. Reading. Overview. What is high-energy astrophysics?
High-Energy Astrophysics Lecture 1: introduction and overview; synchrotron radiation Robert Laing Lectures: Week 1: M 10, T 9 Timetable Week 2: M 10, T 9, W 10 Week 3: M 10, T 9, W 10 Week 4: M 10, T 9,
More informationThe Phenomenon of Active Galactic Nuclei: an Introduction
The Phenomenon of Active Galactic Nuclei: an Introduction Outline Active Galactic Nuclei (AGN): > Why are they special? > The power source > Sources of Continuum Emission > Emission & absorption lines
More informationActive Galaxies & Emission Line Diagnostics
Active Galaxies & Emission Line Diagnostics Review of Properties Discussed: 1) Powered by accretion unto a supermassive nuclear black hole 2) They are the possible precursors to luminous massive galaxies
More information2. Active Galaxies. 2.1 Taxonomy 2.2 The mass of the central engine 2.3 Models of AGNs 2.4 Quasars as cosmological probes.
2. Active Galaxies 2.1 Taxonomy 2.2 The mass of the central engine 2.3 Models of AGNs 2.4 Quasars as cosmological probes Read JL chapter 3 Active galaxies: interface with JL All of JL chapter 3 is examinable,
More informationPart two of a year-long introduction to astrophysics:
ASTR 3830 Astrophysics 2 - Galactic and Extragalactic Phil Armitage office: JILA tower A909 email: pja@jilau1.colorado.edu Spitzer Space telescope image of M81 Part two of a year-long introduction to astrophysics:
More informationExtragalactic Radio Sources. Joanne M. Attridge MIT Haystack Observatory
Extragalactic Radio Sources Joanne M. Attridge MIT Haystack Observatory It all began in the 1940s... Galaxies=condensations of gas, dust and stars held together by their own gravitational potential M 87
More informationStructure of nuclei of extragalactic radio sources and the link with GAIA
Structure of nuclei of extragalactic radio sources and the link with GAIA J Roland, IAP & S Lambert, SYRTE I General properties of extragalactic radio sources Radio galaxies : associated with elliptical
More informationSimultaneous X-ray and Radio Observations of Seyferts, and Disk-Jet Connections
Simultaneous X-ray and Radio Observations of Seyferts, and Disk-Jet Connections Ashley Lianne King, University of Michigan Advisor: Jon M. Miller Collaborators: John Raymond, Michael Rupen, Kayhan Gültekin,
More informationACTIVE GALACTIC NUCLEI: FROM THE CENTRAL BLACK HOLE TO THE GALACTIC ENVIRONMENT
Julian H. Krolik ACTIVE GALACTIC NUCLEI: FROM THE CENTRAL BLACK HOLE TO THE GALACTIC ENVIRONMENT PRINCETON UNIVERSITY PRESS Princeton, New Jersey Preface Guide for Readers xv xix 1. What Are Active Galactic
More informationTEMA 6. Continuum Emission
TEMA 6. Continuum Emission AGN Dr. Juan Pablo Torres-Papaqui Departamento de Astronomía Universidad de Guanajuato DA-UG (México) papaqui@astro.ugto.mx División de Ciencias Naturales y Exactas, Campus Guanajuato,
More informationDark Matter ASTR 2120 Sarazin. Bullet Cluster of Galaxies - Dark Matter Lab
Dark Matter ASTR 2120 Sarazin Bullet Cluster of Galaxies - Dark Matter Lab Mergers: Test of Dark Matter vs. Modified Gravity Gas behind DM Galaxies DM = location of gravity Gas = location of most baryons
More informationBH Astrophys Ch1~2.2. h"p://www.astro.princeton.edu/~burrows/classes/250/distant_galaxies.html h"p://abyss.uoregon.edu/~js/ast123/lectures/lec12.
BH Astrophys Ch1~2.2 h"p://www.astro.princeton.edu/~burrows/classes/250/distant_galaxies.html h"p://abyss.uoregon.edu/~js/ast123/lectures/lec12.html Outline Ch1. 1. Why do we think they are Black Holes?(1.1-1.2)
More informationThe Black Hole in the Galactic Center. Eliot Quataert (UC Berkeley)
The Black Hole in the Galactic Center Eliot Quataert (UC Berkeley) Why focus on the Galactic Center? The Best Evidence for a BH: M 3.6 10 6 M (M = mass of sun) It s s close! only ~ 10 55 Planck Lengths
More informationA Unified Model for AGN. Ryan Yamada Astro 671 March 27, 2006
A Unified Model for AGN Ryan Yamada Astro 671 March 27, 2006 Overview Introduction to AGN Evidence for unified model Structure Radiative transfer models for dusty torus Active Galactic Nuclei Emission-line
More informationRadiative Processes in Astrophysics
Radiative Processes in Astrophysics 11. Synchrotron Radiation & Compton Scattering Eline Tolstoy http://www.astro.rug.nl/~etolstoy/astroa07/ Synchrotron Self-Absorption synchrotron emission is accompanied
More informationBlack Holes in Hibernation
Black Holes in Hibernation Black Holes in Hibernation Only about 1 in 100 galaxies contains an active nucleus. This however does not mean that most galaxies do no have SMBHs since activity also requires
More informationObservational Evidence of AGN Feedback
10 de maio de 2012 Sumário Introduction AGN winds Galaxy outflows From the peak to the late evolution of AGN and quasars Mergers or secular evolution? The AGN feedback The interaction process between the
More informationBright Quasar 3C 273 Thierry J-L Courvoisier. Encyclopedia of Astronomy & Astrophysics P. Murdin
eaa.iop.org DOI: 10.1888/0333750888/2368 Bright Quasar 3C 273 Thierry J-L Courvoisier From Encyclopedia of Astronomy & Astrophysics P. Murdin IOP Publishing Ltd 2006 ISBN: 0333750888 Institute of Physics
More information1932: KARL JANSKY. 1935: noise is identified as coming from inner regions of Milky Way
1932: KARL JANSKY Is assigned the task of identifying the noise that plagued telephone calls to Europe 1935: noise is identified as coming from inner regions of Milky Way MANY YEARS GO BY. 1960: a strong
More informationChapter 19 Galaxies. Hubble Ultra Deep Field: Each dot is a galaxy of stars. More distant, further into the past. halo
Chapter 19 Galaxies Hubble Ultra Deep Field: Each dot is a galaxy of stars. More distant, further into the past halo disk bulge Barred Spiral Galaxy: Has a bar of stars across the bulge Spiral Galaxy 1
More informationAGN in hierarchical galaxy formation models
AGN in hierarchical galaxy formation models Nikos Fanidakis and C.M. Baugh, R.G. Bower, S. Cole, C. Done, C. S. Frenk Physics of Galactic Nuclei, Ringberg Castle, June 18, 2009 Outline Brief introduction
More informationA. Thermal radiation from a massive star cluster. B. Emission lines from hot gas C. 21 cm from hydrogen D. Synchrotron radiation from a black hole
ASTR 1040 Accel Astro: Stars & Galaxies Prof. Juri Toomre TA: Nicholas Nelson Lecture 26 Thur 14 Apr 2011 zeus.colorado.edu/astr1040-toomre toomre HST Abell 2218 Reading clicker what makes the light? What
More informationStarbursts, AGN, and Interacting Galaxies 1 ST READER: ROBERT GLEISINGER 2 ND READER: WOLFGANG KLASSEN
Starbursts, AGN, and Interacting Galaxies 1 ST READER: ROBERT GLEISINGER 2 ND READER: WOLFGANG KLASSEN Galaxy Interactions Galaxy Interactions Major and Minor Major interactions are interactions in which
More informationDistribution of X-ray binary stars in the Galaxy (RXTE) High-Energy Astrophysics Lecture 8: Accretion and jets in binary stars
High-Energy Astrophysics Lecture 8: Accretion and jets in binary stars Distribution of X-ray binary stars in the Galaxy (RXTE) Robert Laing Primary Compact accreting binary systems Compact star WD NS BH
More informationSpins of Supermassive Black Holes. Ruth A. Daly
Spins of Supermassive Black Holes Ruth A. Daly Three key quantities characterize a black hole: mass, spin, and charge. Astrophysical black holes are thought to have zero net charge, and thus are characterized
More informationActive Galactic Alexander David M Nuclei
d.m.alexander@durham.ac.uk Durham University David M Alexander Active Galactic Nuclei The Power Source QuickTime and a YUV420 codec decompressor are needed to see this picture. Black hole is one billionth
More informationChapter 21 Galaxy Evolution. How do we observe the life histories of galaxies?
Chapter 21 Galaxy Evolution How do we observe the life histories of galaxies? Deep observations show us very distant galaxies as they were much earlier in time (old light from young galaxies). 1 Observing
More informationHigh-Energy Astrophysics
Oxford Physics: Part C Major Option Astrophysics High-Energy Astrophysics Garret Cotter garret@astro.ox.ac.uk Office 756 DWB Michaelmas 2011 Lecture 9 Today s lecture: Black Holes and jets Part I Evidence
More informationActive Galactic Nuclei-I. The paradigm
Active Galactic Nuclei-I The paradigm An accretion disk around a supermassive black hole M. Almudena Prieto, July 2007, Unv. Nacional de Bogota Centers of galaxies Centers of galaxies are the most powerful
More informationRadio Galaxies. D.Maino. Radio Astronomy II. Physics Dept., University of Milano. D.Maino Radio Galaxies 1/47
Radio Galaxies D.Maino Physics Dept., University of Milano Radio Astronomy II D.Maino Radio Galaxies 1/47 Active Galactic Nuclei AGN: nuclei of galaxies with energetic phenomena that can not clearly and
More informationACTIVE GALACTIC NUCLEI I. AN INTRODUCTION Sebastian F. Hoenig Lecturer & Marie Curie Fellow Outline and learning goals I. Phenomenology What are AGN? How are they identified? II. Energy output Where is
More informationBroadband X-ray emission from radio-quiet Active Galactic Nuclei
29 th ASI Meeting ASI Conference Series, 2011, Vol. 3, pp 19 23 Edited by Pushpa Khare & C. H. Ishwara-Chandra Broadband X-ray emission from radio-quiet Active Galactic Nuclei G. C. Dewangan Inter-University
More informationSchwarzchild Radius. Black Hole Event Horizon 30 km 9 km. Mass (solar) Object Star. Star. Rs = 3 x M (Rs in km; M in solar masses)
Schwarzchild Radius The radius where escape speed = the speed of light. Rs = 2 GM/c2 Rs = 3 x M (Rs in km; M in solar masses) A sphere of radius Rs around the black hole is called the event horizon. Object
More informationQuasars: Back to the Infant Universe
Quasars: Back to the Infant Universe Learning Objectives! What is a quasar? What spectral features tell us quasars are very redshifted (very distant)? What spectral features tell us they are composed of
More informationIn a dense region all roads lead to a black Hole (Rees 1984 ARAA) Deriving the Mass of SuperMassive Black Holes
In a dense region all roads lead to a black Hole (Rees 1984 ARAA) Deriving the Mass of SuperMassive Black Holes Stellar velocity fields MW Distant galaxies Gas motions gas disks around nearby black holes
More informationHigh-Energy Astrophysics
Part C Major Option Astrophysics High-Energy Astrophysics Garret Cotter garret@astro.ox.ac.uk Office 756 DWB Lecture 10 - rescheduled to HT 2013 Week 1 Today s lecture AGN luminosity functions and their
More information(Astro)Physics 343 Lecture # 12: active galactic nuclei
(Astro)Physics 343 Lecture # 12: active galactic nuclei Schedule for this week Monday & Tuesday 4/21 22: ad hoc office hours for Lab # 5 (you can use the computer in my office if necessary; Sections A
More informationEvidence for BH: Active Galaxies
Evidence for BH: Active Galaxies This is the first of two lectures in which we ll talk about evidence for the existence of black holes in the universe. It is actually in the next lecture, where we ll talk
More informationEvidence for BH: Active Galaxies
Evidence for BH: Active Galaxies This is the second lecture in which we ll talk about evidence for the existence of black holes in the universe. Here we focus on active galactic nuclei, or AGN. Black holes
More informationLecture 11 Quiz 2. AGN and You. A Brief History of AGN. This week's topics
Lecture 11 Quiz 2 AGN and You March 25 2003 8:00 PM BPS 1420 1. What system of time do astronomers use rather than the standard day-month-year system? 2. In that system, how long would it be between noon
More informationAGN Physics of the Ionized Gas Physical conditions in the NLR Physical conditions in the BLR LINERs Emission-Line Diagnostics High-Energy Effects
AGN Physics of the Ionized Gas Physical conditions in the NLR Physical conditions in the BLR LINERs Emission-Line Diagnostics High-Energy Effects 1 Evidence for Photoionization - continuum and Hβ luminosity
More informationUniversity of California, Santa Barbara Department of Physics
University of California, Santa Barbara Department of Physics Name: KEY Astronomy FINAL EXAM Prof. Antonucci Tuesday, June Spring 008 I give my permission for my graded exam to be left in a public place:
More informationMeasuring Black Hole Spin in AGN. Laura Brenneman (Harvard-Smithsonian CfA)
Measuring Black Hole Spin in AGN Laura Brenneman (Harvard-Smithsonian CfA) Single and Double Special Massive thanks Black to: Holes in Galaxies Chris Reynolds, University Andy Fabian, of Michigan Martin
More informationLecture 20 High-Energy Astronomy. HEA intro X-ray astrophysics a very brief run through. Swift & GRBs 6.4 kev Fe line and the Kerr metric
Lecture 20 High-Energy Astronomy HEA intro X-ray astrophysics a very brief run through. Swift & GRBs 6.4 kev Fe line and the Kerr metric Tut 5 remarks Generally much better. However: Beam area. T inst
More informationConnections between Radio and High Energy Emission in AGN
Connections between Radio and High Energy Emission in AGN Geoff Bicknell Research School of Astronomy & Astrophysics Australian National University 1 Collaborators: Loredana Bassani, INAF, Bologna Nadine
More informationAn Introduction to Radio Astronomy
An Introduction to Radio Astronomy Bernard F. Burke Massachusetts Institute of Technology and Francis Graham-Smith Jodrell Bank, University of Manchester CAMBRIDGE UNIVERSITY PRESS Contents Preface Acknowledgements
More informationOrianne ROOS CEA-Saclay Collaborators : F. Bournaud, J. Gabor, S. Juneau
Orianne ROOS CEA-Saclay Collaborators : F. Bournaud, J. Gabor, S. Juneau Bachelor of Physics, Master of Astrophysics Université de Strasbourg PhD, Université Paris-Diderot Observatoire de Strasbourg Les
More informationAstronomy 210 Final. Astronomy: The Big Picture. Outline
Astronomy 210 Final This Class (Lecture 40): The Big Bang Next Class: The end HW #11 Due next Weds. Final is May 10 th. Review session: May 6 th or May 9 th? Designed to be 2 hours long 1 st half is just
More informationThe hazy band of the Milky Way is our wheel-shaped galaxy seen from within, but its size
C H A P T E R 15 THE MILKY WAY GALAXY 15-1 THE NATURE OF THE MILKY WAY GALAXY How do astronomers know we live in a galaxy? The hazy band of the Milky Way is our wheel-shaped galaxy seen from within, but
More informationThe Classification of Galaxies
Admin. 11/9/17 1. Class website http://www.astro.ufl.edu/~jt/teaching/ast1002/ 2. Optional Discussion sections: Tue. ~11.30am (period 5), Bryant 3; Thur. ~12.30pm (end of period 5 and period 6), start
More informationFeeding the Beast. Chris Impey (University of Arizona)
Feeding the Beast Chris Impey (University of Arizona) Note: the box is growing due to cosmic expansion but this is factored out. Heirarchical Structure Active Galactic Nuclei (AGN) Nuclear activity in
More informationGalaxies and Cosmology
F. Combes P. Boisse A. Mazure A. Blanchard Galaxies and Cosmology Translated by M. Seymour With 192 Figures Springer Contents General Introduction 1 1 The Classification and Morphology of Galaxies 5 1.1
More informationBlack holes as central engines
Chapter 15 Black holes as central engines Black holes imply a fundamental modification of our understanding of space and time. But at a more mundane level they also are of great practical importance in
More informationMass loss from stars
Mass loss from stars Can significantly affect a star s evolution, since the mass is such a critical parameter (e.g., L ~ M 4 ) Material ejected into interstellar medium (ISM) may be nuclear-processed:
More informationAn Introduction to Radio Astronomy
An Introduction to Radio Astronomy Second edition Bernard F. Burke and Francis Graham-Smith CAMBRIDGE UNIVERSITY PRESS Contents Preface to the second edition page x 1 Introduction 1 1.1 The role of radio
More informationGalaxies. With a touch of cosmology
Galaxies With a touch of cosmology Types of Galaxies Spiral Elliptical Irregular Spiral Galaxies Spiral Galaxies Disk component where the spiral arms are Interstellar medium Star formation Spheroidal
More informationX-ray variability of AGN
X-ray variability of AGN Magnus Axelsson October 20, 2006 Abstract X-ray variability has proven to be an effective diagnostic both for Galactic black-hole binaries and active galactic nuclei (AGN). This
More informationIntroduction to High Energy Astrophysics
Introduction to High Energy Astrophysics Books 2011 2006 - for the history of the subject 1 The Sky in Different Astronomical Wavebands The context for high energy astrophysics Optical Infrared Millimetre-submillimetre
More information4/18/17. Our Schedule. Revisit Quasar 3C273. Dark Matter in the Universe. ASTR 1040: Stars & Galaxies
ASTR 1040: Stars & Galaxies HST Abell 2218 Prof. Juri Toomre TAs: Piyush Agrawal, Connor Bice Lecture 25 Tues 18 Apr 2017 zeus.colorado.edu/astr1040-toomre Our Schedule Observatory Night #8 + #9 (proj
More informationSynchrotron Radiation: II. Spectrum
Synchrotron Radiation: II. Spectrum Massimo Ricotti ricotti@astro.umd.edu University of Maryland Synchrotron Radiation: II. Spectrum p.1/18 ds=v dt_em dt=ds cos(theta)/c=v/c cos(theta)dt_em Synchrotron
More informationGalaxies with radio and optical jets Françoise Combes
Chaire Galaxies et Cosmologie Galaxies with radio and optical jets Françoise Combes The jet: component of the standard model Less than 10% of galaxies have an active nucleus. 10% of AGN have Radio jets
More informationAGN and Radio Galaxy Studies with LOFAR and SKA
AGN and Radio Galaxy Studies with LOFAR and SKA Andrei Lobanov MPIfR, Bonn AGN/RG Science AGN/RG drivers for LOFAR and SKA: astrophysical masers, nuclear regions of AGN, physics of relativistic and mildly
More informationObserving the Formation of Dense Stellar Nuclei at Low and High Redshift (?) Roderik Overzier Max-Planck-Institute for Astrophysics
Observing the Formation of Dense Stellar Nuclei at Low and High Redshift (?) Roderik Overzier Max-Planck-Institute for Astrophysics with: Tim Heckman (JHU) GALEX Science Team (PI: Chris Martin), Lee Armus,
More informationAtomic Structure & Radiative Transitions
Atomic Structure & Radiative Transitions electron kinetic energy nucleus-electron interaction electron-electron interaction Remember the meaning of spherical harmonics Y l, m (θ, ϕ) n specifies the
More information