brlsijune2004

Information about brlsijune2004

Published on November 29, 2007

Author: Cannes

Source: authorstream.com

Content

Cosmic Fireworks: X-Rays From Black Holes:  Cosmic Fireworks: X-Rays From Black Holes Daniel Evans Contents:  Contents My background What is a black hole? Telescopes What is an active galaxy? Do active galaxies harbour black holes? Case study: Centaurus A What can black holes tell us about the Universe as a whole? My Background:  My Background M.Sci. Physics, Grey College, University of Durham Supervisor Professor Sir Arnold Wolfendale, F.R.S., 14th Astronomer Royal My Background:  My Background Ph.D. Astrophysics University of Bristol Harvard-Smithsonian Center for Astrophysics What is a black hole?:  What is a black hole? “Nothing travels faster than light” What is a black hole?:  What is a black hole? Concept All objects with mass have gravity (e.g. the Earth) “Jump” with sufficient speed  escape Earth’s gravity (think space shuttles) Einstein: nothing is faster than light What is a black hole?:  What is a black hole? What is a black hole?:  What is a black hole? How heavy? From a few x the mass of the sun up to 1 billion x the mass of the sun (See later!) How big? Fairly simple (GCSE/A Level) physics! For 3 x the mass of the sun, event horizon = 3 km For 1 billion x the mass of the sun, event horizon = 1 AU (Earth-Sun distance) What is a black hole?:  What is a black hole? EH X-Ray Telescopes:  X-Ray Telescopes XMM-Newton (ESA) Launched in 1999 3.8 tonnes Largest satellite built in Europe Very large collecting area Good resolution X-Ray Telescopes:  X-Ray Telescopes X-Ray Telescopes:  X-Ray Telescopes Chandra (NASA/SAO) Launched in 1999 on STS-93 (Columbia) 25 tonnes Largest object ever carried by shuttle Exceptionally high resolution X-Ray Telescopes:  X-Ray Telescopes X-Ray Telescopes:  X-Ray Telescopes “First Light”: SNR Cas A What is an Active Galaxy?:  What is an Active Galaxy? Take a “normal” galaxy: The “Sombrero” galaxy The total energy is the sum of all the energy from the stars What is an Active Galaxy?:  What is an Active Galaxy? This is not the case in an active galaxy There are very bright core and jet components This is not starlight! In some cases (e.g. quasars) the non-stellar emission completely dominates What is an Active Galaxy?:  What is an Active Galaxy? Something very heavy is lurking at the centre… Evidence: 1. Very bright central core, often a jet Chandra X- ray image of NGC 6251 Core Jet Power = 1 billion billion billion billion Watts E=mc2  highly efficient What is an Active Galaxy?:  What is an Active Galaxy? 2. Orbital speeds Again, using fairly simple physics, we can use the velocities of orbiting objects to estimate the mass of the central core What is an Active Galaxy?:  What is an Active Galaxy? 3. (A bit more technical): Relativistic broadening of X-ray emission lines (Einstein again): Something is orbiting very fast around something very heavy What is an Active Galaxy?:  What is an Active Galaxy? The central object is also small A B What is an Active Galaxy?:  What is an Active Galaxy? The central object is also small A B What is an Active Galaxy?:  What is an Active Galaxy? The central object is also small A B What is an Active Galaxy?:  What is an Active Galaxy? The central object is also small A B What is an Active Galaxy?:  What is an Active Galaxy? The central object is also small A B What is an Active Galaxy?:  What is an Active Galaxy? The central object is also small A B d = ct c = speed of light d = diameter The ‘red’ light reaches us over a period t, say 1 ms Do Active Galaxies Harbour Black Holes?:  Do Active Galaxies Harbour Black Holes? Candidates for the “heavy central object”: 1. A supermassive star Non-rotating star unstable on a timescale of approx 10 million years (too low – Universe is around 15 billion years old) Can be stabilised by rotation, but general relativity predicts additional instability and star evolves into black hole Do Active Galaxies Harbour Black Holes?:  Do Active Galaxies Harbour Black Holes? 2. A “starburst” nucleus A dense cluster of massive, rapidly evolving stars lies in the nucleus, undergoing many supernova explosions Radio observations demonstrate well-ordered motions (ie jets!) which are hard to explain in a model involving random outbursts Do Active Galaxies Harbour Black Holes?:  Do Active Galaxies Harbour Black Holes? 3. A black hole! Centaurus A:  Centaurus A Closest active galaxy (11 million light years) Complex structure on all scales Studied across the electromagnetic spectrum Multiwavelength Centaurus A:  Multiwavelength Centaurus A Optical and IR Elliptical galaxy crossed by dust lane Evidence for a recent merger Recession velocity = 540 km/s, z=0.0018 HST: 130 light year diameter disk. Material fed into inner accretion disk Slide31:  Blanca 4m telescope image Multiwavelength Centaurus A:  Multiwavelength Centaurus A Radio overview 8o x 4o extended, diffuse emission Inner radio lobes NE and SW of the centre Predominantly one-sided jet NE of the centre Inner jet and nucleus Tingay et al. (1998) Multiwavelength Centaurus A:  Multiwavelength Centaurus A Haslam 408 MHz radio all-sky map Multiwavelength Centaurus A:  Multiwavelength Centaurus A Radio: VLA Synchrotron radiation Slide37:  Radio X-ray (Hardcastle et al. 2003) Multiwavelength Centaurus A:  Multiwavelength Centaurus A X-ray: Brightest extragalactic object in the hard X-ray sky Ideal object to study Much-studied by earlier X-ray missions Slide39:  Thermal gas Jet Point Sources SW Radio Lobe Nucleus 31 knots Synchrotron radiation 246 detected “X-ray binaries” X-ray emitting plasma surrounding lobe Supersonic expansion Elliptical galaxy Incredibly luminous Centaurus A - Spectrum:  Centaurus A - Spectrum Now we turn to spectral analysis Spectra can tell us the elements and physical processes present in the black hole system Centaurus A - Spectrum:  Centaurus A - Spectrum Centaurus A - Spectrum:  Centaurus A - Spectrum Centaurus A - Results:  What can I tell from this? There is a dense and incredibly luminous core A powerful jet extends into the intergalactic medium (space) There is an elliptical host galaxy underneath Centaurus A - Results Centaurus A - Conclusions:  Major conclusions Strong evidence for a supermassive black hole in the centre of Cen A Energy generation mechanisms classified A picture emerges… Centaurus A - Conclusions Let’s Take This To Higher Distances:  Let’s Take This To Higher Distances AGN are bright They can be seen out to very large distances (14 billion light years) They can be used to probe cosmological models Let’s Take This To Higher Distances:  Let’s Take This To Higher Distances The 2QZ survey: Used to measure the position on the sky, and redshift (~distance) of quasars (a type of active galaxy) Theory Experiment Results Of Survey:  Results Of Survey Up until about 10-15 years ago, we thought that the Universe was composed entirely of matter. This turned out to be wrong… Amazingly, we know for sure just 3% of the energy density This is ordinary matter (baryonic)  27% is dark matter  70% is dark energy/ quintessence/ cosmological constant Summary:  Summary Very strong evidence that supermassive black holes exist at the heart of all AGN They have a mass ~ 100 million x the mass of the sun AGN often form jets AGN tell us that the energy content of the Universe is dominated by “dark energy”

Related presentations


Other presentations created by Cannes

infosys europe
15. 10. 2007
0 views

infosys europe

dns pres minda bgp anycast
27. 09. 2007
0 views

dns pres minda bgp anycast

Geography of East Asia
04. 10. 2007
0 views

Geography of East Asia

Cohen Akiba
08. 10. 2007
0 views

Cohen Akiba

Arnold Schwarzenegger
11. 10. 2007
0 views

Arnold Schwarzenegger

IPv6 development in China
12. 10. 2007
0 views

IPv6 development in China

Zambia powerpoint
12. 10. 2007
0 views

Zambia powerpoint

DB CTSC SAP WinSQL
13. 10. 2007
0 views

DB CTSC SAP WinSQL

met50 10 1
05. 10. 2007
0 views

met50 10 1

2006 BSUA Motivating Employees
02. 11. 2007
0 views

2006 BSUA Motivating Employees

Einstein
13. 11. 2007
0 views

Einstein

Naji
23. 10. 2007
0 views

Naji

BOP FJG V4
19. 11. 2007
0 views

BOP FJG V4

Chap009
20. 11. 2007
0 views

Chap009

Melissa Theuriau
26. 11. 2007
0 views

Melissa Theuriau

fos
03. 01. 2008
0 views

fos

JPChen Spin hallameeting
12. 10. 2007
0 views

JPChen Spin hallameeting

lecture series
05. 01. 2008
0 views

lecture series

tmT
24. 10. 2007
0 views

tmT

4 01
15. 10. 2007
0 views

4 01

sv centroamerica
22. 10. 2007
0 views

sv centroamerica

cosmology 2005
16. 10. 2007
0 views

cosmology 2005

Kulikova
26. 10. 2007
0 views

Kulikova

New lecture 3
16. 02. 2008
0 views

New lecture 3

Auditory Games for Babies
27. 11. 2007
0 views

Auditory Games for Babies

Outburst5
20. 02. 2008
0 views

Outburst5

glutdema
04. 10. 2007
0 views

glutdema

TaifunlPresentation SwiNOG
17. 10. 2007
0 views

TaifunlPresentation SwiNOG

Profitability Analysis
24. 02. 2008
0 views

Profitability Analysis

ALA 2005 Dewey Update
29. 09. 2007
0 views

ALA 2005 Dewey Update

PrelimII
07. 10. 2007
0 views

PrelimII

Genmanipulation
02. 11. 2007
0 views

Genmanipulation

quadstate
26. 03. 2008
0 views

quadstate

Wood vinegar
14. 02. 2008
0 views

Wood vinegar

GlobalChange GHG
07. 04. 2008
0 views

GlobalChange GHG

colombia presentation
27. 03. 2008
0 views

colombia presentation

STB OrgChart 051130
30. 03. 2008
0 views

STB OrgChart 051130

Schafer
30. 12. 2007
0 views

Schafer

newconservatism
10. 04. 2008
0 views

newconservatism

deflation
13. 04. 2008
0 views

deflation

3 Miles Park
16. 04. 2008
0 views

3 Miles Park

march frames tam
17. 04. 2008
0 views

march frames tam

236 SeoulHFFaunce
22. 04. 2008
0 views

236 SeoulHFFaunce

Eclipse2008
15. 10. 2007
0 views

Eclipse2008

PS142 lecture22
28. 12. 2007
0 views

PS142 lecture22

nbi03 mcgregor target
09. 10. 2007
0 views

nbi03 mcgregor target

dbaFile4231
12. 10. 2007
0 views

dbaFile4231

gen port overview
29. 02. 2008
0 views

gen port overview

Underwater Vehicles
07. 11. 2007
0 views

Underwater Vehicles

Programa Completo mes a Euskera
23. 10. 2007
0 views

Programa Completo mes a Euskera

Stoll Realtime
02. 01. 2008
0 views

Stoll Realtime

final southPole
15. 11. 2007
0 views

final southPole

Sandberg
15. 10. 2007
0 views

Sandberg

Turkey 6
23. 11. 2007
0 views

Turkey 6

PIM BS 2007 TK 1 3
16. 11. 2007
0 views

PIM BS 2007 TK 1 3

leipzigrda
03. 10. 2007
0 views

leipzigrda

burtonzoo
10. 10. 2007
0 views

burtonzoo