High energy Astrophysics
description
Transcript of High energy Astrophysics
High energy Astrophysics
Mat Page
Mullard Space Science Lab, UCL
2. X-ray and -ray sources
2. The X-ray / -ray sources (the zoo)
• This lecture:• An exhaustive inventory of X-ray sources
• Why they emit X-rays
• Where they are in the sky
• Where they are in the electromagnetic spectrum
Slide 2
Images of the sun over its 11 year activity cycle from the Yohkoh Soft X-ray telescope
The Sun
X-ray luminosity 1019-1021 W
Slide 3
Planets, the moon and comets
Jupiter seen by Chandra
Jupiter at time of Shoemaker-Levy 9 impact (Rosat)
Slide 4
X-ray luminosity ~ 5x109 W
Planets, the moon and comets
The Moon!
You can also see the X-ray background in this picture!
Slide 5
X-ray luminosity ~ 4x106 W
Planets, the moon and comets
Comet Hyakutake!
Slide 6
X-ray luminosities 106-109W
Normal stars
Stars in the Stars in the open cluster open cluster NGC 2516 NGC 2516 (Rosat)(Rosat)
Slide 7
X-ray luminosities of up to 1024 W
Massive stars
The bright source in the centre of NGC 3606 is due to the colliding winds from massive stars
Slide 8
X-ray luminosities of up to 1026 W
Supernova remnants
Cas-A and Tycho supernova remnants (Chandra)
Slide 9
X-ray luminosities of up to 1030 W
Compact stars
This 5 hour time sequence from the Einstein observatory shows pulses of X-ray emission from the Crab pulsar
Slide 10
X-ray luminosities of up to 1029 W
Interacting binaries
Interacting binaries in the globular cluster 47-Tuc
Slide 11
X-ray luminosities of up to 1032 W
galaxies
M82 as seen by Chandra, with an optical image (in blue) superimposed in the right panel
Slide 12
X-ray luminosities of up to 1035 W
AGN
The quasar 3C273 and its X-ray jet as seen by Chandra
Slide 13
X-ray luminosities of up to 1039 W
Clusters of galaxies
Coma
Slide 14
X-ray luminosities of up to 1038 W
Luminosities
(W)
Slide 15
Some key points:
• Surprisingly, a whole host of objects have been detected as X-ray sources.
• Strong magnetic fields can accelerate particles to high velocities to produce X-ray emission, for example in the coronae of the Sun and other normal stars, and in planetary aurorae.
• Fast shock waves are another source of high energy emission, for example in supernova remnants and when stellar winds collide.
• The most luminous X-ray sources (AGN, clusters of galaxies, accreting binaries) are powered by gravitational potential energy.
Slide 16