Black Hole Chaos

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Transcript Black Hole Chaos

Black Hole Chaos
The Environments of the most supermassive black holes in the Universe
Belinda Wilkes, Chandra X-ray Center, CfA
Francesca Civano, CfA
Black Hole
• Nothing beats gravity
→ collapses forever
• Light cannot escape
from inside the event
Matter spiraling inwards
→ accretion disk
Stellar Mass Black Hole
• Big, old star blows up
• Can be seen when in binary
star systems
• BH pulls matter from
companion star
• Bright, variable/bursting
BH and
accretion disk
Black Hole: Mass and Spin
• Properties determine their effects on their surroundings
• Spinning BH has a smaller “size” (event horizon is closer in)
No spin
With spin
Super-massive Black Hole (SMBH)
• Formed in centers of
galaxies in early
• 1 million – 1 billion
times Sun’s mass
• SMBH size ~ our solar
system (15 lt mins)
• SMBH grows as
material falls in
Central Regions:
Accretion Disk spinning around
• Matter spirals in to galactic
center and forms an
accretion disk (~few lt.yrs.)
• Becomes very hot and
outshines the 10 billion stars
in the host galaxy → Quasar
• Hottest near center
• X-rays good clear view, even
when edge-on
• BH grows as matter falls in
• Other matter is pushed
outwards: jets, winds
Artist’s Impressions!
But this one is
real: Cen A
Model of Polar Jets
Accretion with
angular momentum
and radial magnetic
field can launch and
sustain a jet
Proga et al. 2003
Radio Jets
• Electrons spiral around
magnetic field at
velocities close to light
• Emit radio-X-rays “nonthermal” emission
Chandra X-ray Observatory
NASA’s X-ray Eye on the Universe
Launched in 1999
Actual Chandra First Light
• Point source to focus
• PKS0637-75, quasar at large
distance (z=0.5, 3 Gpc)
• Shadow on side!
• Known to have radio jet
• X-ray Jet visible: 5” long,
200,000 lyrs
X-ray/Radio Jets in Quasars: M87 Galaxy
M87 jet in X-ray, radio and optical
More jets!
Cygnus A
Accretion Disk Winds
• Wind blown off
surface of accretion
• Accelerated by
radiation pressure
• High velocity gas
X-ray source
Proga et al. 2000
AD surface
How do SMBHs form and grow?
Secular: accreting from within the galaxy
Group: accretes from within the group of galaxies
Cosmological: accretes from cold dark matter filaments
Major Mergers:
Hopkins et al (2008)