Brightest-Ever 'Blazar' Flare from Distant Galaxy Spotted by NASA's Fermi Gamma-Ray Space Telescope

[n2doc]

ScienceDaily (Dec. 12, 2009) — A galaxy located billions of light-years away is commanding the attention of NASA's Fermi Gamma-ray Space Telescope and astronomers around the globe. Thanks to a series of flares that began September 15, the galaxy is now the brightest source in the gamma-ray sky -- more than ten times brighter than it was in the summer.



Astronomers identify the object as 3C 454.3, an active galaxy located 7.2 billion light-years away in the constellation Pegasus. But even among active galaxies, it's exceptional.

"We're looking right down the barrel of a particle jet powered by the galaxy's supermassive black hole," said Gino Tosti at the National Institute of Nuclear Physics in Perugia, Italy. "Some change within that jet -- we don't know what -- is likely responsible for these flares."

Blazars, like many active galaxies, emit oppositely directed jets of particles traveling near the speed of light when matter falls toward their central supermassive black holes. What makes a blazar so bright in gamma rays is its orientation: One of the jets happens to be aimed straight at us.

Most of the time, the brightest persistent source in the gamma-ray sky is the Vela pulsar, which at a distance of about 1,000 light-years lies practically next door.

http://www.sciencedaily.com/releases/2009/12/091209151440.htm

[denem]

1. "One of the jets happens to be aimed straight at us"

10^6+ more, and there may be no us.

[clear eye]

4. How terrified should I be? n/t

[Vinnie From Indy]

2. Most humans are blissfully ignorant of the fact that a Gamma Ray Burst

can virtually sterilize the Earth's surface should we be directly in the path of one of the two beams created by these super massive black holes. The amounts of energy in these GRB's is second only to the big bang itself. As I understand it, we can be destroyed by a GRB even if the event happened very, very far away. I just finished reading an excellent book by astronomer Phil Plait. The title is Death From the Skies. It gives a laundry list of all the ways the universe can kill us all. I was actually surprised by the number of celestial things that can kill us. Some of the things like a direct hit from gamma ray burst would only appear as a bright flash in the sky on the side of the earth that is hit. The bright flash would quickly fade away. The dying would begin shortly thereafter from all sorts of nasty stuff like the destruction of most of the Ozone layer and muons raining down on the Earth. A great read if you like that kind of stuff.

[clear eye]

3. That's why I clicked on this thread--

to mention that we don't really want one any closer or bigger even if it would be easier to study.

A corollary to the dangers from space is that sentient life is likely far rarer than guys like Carl Sagan thought. It takes a long time of lots of luck for such complex nervous systems to evolve.

Then there's the category of inevitables. For a couple billion years, our moon has stabilized the earth's axis, causing climates and forces to be very predictable. However the moon is drifting away which will eventually lead to an Earth that sways around in a way that will probably extinguish life. This would be long before the sun changed dangerously.

We really do have to cherish what we've got. It's a rare and precious gift.