Is M82

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Exploding?
Is M82
Many outflowing (1000 km/sec), escaping warm gas
filaments , Shown in red
Cause is not so unusual thousands of young stars
and their supernova explosions (leave it for
Alex), spread over this dwarf galaxy
Total energy produced is less than the starlight
from the rest of the galaxy, and it emerges
gradually, along directions of easiest escape (a
slow boil)
Credit Subaru Telescope
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An utterly more bizarre jet from M87 (HST image
of this Giant Elliptical Galaxy in the nearby
Virgo Cluster
A highly collimated jet
Nucleus of the galaxy
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More Surprises1) the M87 jet produces the most
powerful radio waves in Virgo2) its energetic
radio lobes are enormous
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• Each zoom step is roughly factor of 10X
  magnification
• Maps from the Very Large Array and a global
  interferrometer give light-year resolution

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M87s jet is not the only oneMore Blasts from
the past

• 1960-70s Radio-astronomers discovered a few
  hundred such galaxies completely unexpected
• The huge double lobes contain a prodigious
  amount of high-energy particles (e.g. electrons),
  which could only have been accelerated by a
  remarkably powerful, long-lived (Myrs) process
• By now many of them have escaped the galaxy, but
  they are still radiating energy by the
  synchrotron mechanism (when electrons spiral in a
  magnetic field at nearly the speed of light)

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Most Powerful Radio Sources in Fornax and Cygnus
Visible stars Radio lobes
Center of galaxy
A pattern in these crimes. What kind of
monster? (Even Billions of) supernovae couldnt
possibly have done this!
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Where did these blasts originate?

• The maps are strongly suggestive The giant
  lobes are the smoke of colossal explosions.
  Since the lobes always point back to
  well-collimated jets which start out in the
  galactic nucleus, that must be where all the
  power originated

get a search warrant
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Another nearby jet, in Centaurus
Close-up of 1-sided jet emerging from the center
blue is X-rays, red is radio
Whitenearby peculiar elliptical galaxy, NGC
5128 Blue/greendouble radio lobes
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Supercomputer Simulations
Re-enact the crime

• In this model calculation, High-speed electron
  Jet starts horizontally from the left, and runs
  for 5.4 million years
• Looks very realistic

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Proof High-energy blasts are originating from
some of these galactic centers currently

• The jets have many lumps, suggestive of an
  erratic energy input.
• Repeated VLBI high-resolution mapping shows
  repeated (unpredictable) ejection of new radio
  blobs of high-energy particles start out at
  speeds of 0.980.99c

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Several years of observations of M87s jetmovie
from J. Biretta
This is ready to go to the grand jury
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New ejections usually come from galactic nuclei
which are currently active (Blasts from Quasars)

• The famous radio jets are often just the tip of
  the iceberg Far more power emerges from the
  Active Galactic Nucleus at high energies,
  including visible light, X-rays and extreme
  Gamma-rays total can exceed output of all the
  starstrillions of solar luminosities!

Jet from powerful Quasar 3C273
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The Quasar Connection to understand jets, we
must understand Active Galactic Nuclei
The crime boss behind the whole operation
Gamma-ray flare erupts in 8 hours, 1000X more
powerful than the entire Milky Way galaxy

• AGN produces its power in a very compact region,
  since R lt c DT ie only a few
  light-hours across, smaller than our Solar
  System!
• The massive central engine of AGN is the
  (bi-polar) high-energy particle accelerator, even
  if its often turned off

Compton Gamma Ray Observatory Mattox, Malkan et
al
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HST Zoom of another jet from a nearby AGN

• Jet appears to emerge perpendi-cular to a gas
  disk around the galactic center

Innuendo
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What is the AGN Central Engine? The Black Hole
Theory
We still can only theorize what makes the Central
Engine tick?

• Best jet model is (chaotic) energy release from
  magnetized matter in close (disk) orbits around
  a giant black hole (highly fuel efficient)
• Spinning disk of gas defines north and south
  polar directionsquasar is a long-lived gyroscope
• The high-speed blasts in our direction have their
  brightness amplified by special relativityis
  this why they appear to start out one-sided?

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Breaking News Blasts from the heart of the
Milky Way
Just when you thought it was safe to go back to
your home on Earth

• The 2.5 Million-solar mass black hole in the
  center of our galaxy is usually starved for fuel,
  but
• It bursts in X-rays about 3 times per week

It spreads to our neighborhood Will we be next??
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Chandra (NASAs third Great Observatory)
discovered the first flare serendipitously then
an intensive followup campaign

• Only the third of five orbits showed comparably
  powerful bursts they are so unpredictable that
  patience and luck are strongly required to study
  them

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2000 October 26-27
(Baganoff et al. 2001)
X-ray power from the center of our galaxy
Oct 27 0542 UT 45x, 4 hr
Time?
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2002 May 22-23 Orbit 1, Part 1
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2002 May 24 Orbit 1, Part 2
May 24 1942 UT 5x, 1.7 hr
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2002 May 25-27 Orbit 2
May 26 0424 UT 6x, 0.75 hr
May 24 1942 UT 5x, 1 hr
May 26 1347 UT 5x, 0.5 hr
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2002 May 28-30 Orbit 3
May 28 1536 UT 25x, 1 hr
May 29 1833 UT 13x, 0.5 hr
May 29 0603 UT 12x, 1.5 hr
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2002 June 3-4 Orbit 5
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Chandra imaging may even show a weak X-ray jet
left over from earlier activity
Plane of Milky Way
Axis of outbursts?
Credit NASA/MIT/F.K. Baganoff et al.
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Conclusions

• We need strong enough gravity in the Universe
  to make many giant black holes in galactic
  centers (as a by-product)
• Unique gravitational strength of a black hole is
  a tremendous accelerator, and a lot of the
  accelerated matter escapes the black hole
  vicinity at nearly c
• The most bizarre objects in the Universe may
  merely be ultra-extreme versions of what lurks in
  the centers of most galaxies
• Total energy (in many forms) produced by black
  holes in the history of the Universe may not be
  that much less than everything generated by
  fusion in stars

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Faster-than-light jets?

• An illusion, produced when matter travels near
  the speed of light, close to our direction

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