Fermi sees brightest-ever blazar flare

Dec 09, 2009 Francis Reddy
Unprecedented flares from the blazar 3C 454.3 in the constellation Pegasus now make it the brightest persistent gamma-ray source in the sky. That title usually goes to the Vela pulsar in our galaxy, which is millions of times closer. These all-sky images, which show the numbers of high-energy gamma-rays captured by Fermi's Large Area Telescope on Dec. 3 and Nov. 18, clearly show the change. Credit: NASA/DOE/Fermi LAT

(PhysOrg.com) -- 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 ," 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 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.

"3C 454.3 is millions of times farther away, yet the current flare makes it twice as bright as Vela," said Lise Escande at the Center for Nuclear Studies in Gradignan, near Bordeaux, France. "That represents an incredible energy release, and one the source can't sustain for very long."

According to Massimo Villata at Italy's Torino Observatory, 3C 454.3 also is flaring at radio and visible wavelengths, if less dramatically. "In red light, the blazar brightened by more than two and a half times to magnitude 13.7, and it is also very bright at high radio frequencies."

The Fermi team is alerting astronomers to monitor the event over as broad a range of wavelengths as possible. "That's our best bet for understanding what's going on inside that jet," Tosti said.

Source: NASA's Goddard Space Flight Center (news : web)

Explore further: POLARBEAR detects curls in the universe's oldest light

add to favorites email to friend print save as pdf

Related Stories

Astrophysicists explore a blazar

Mar 18, 2009

An international team of astrophysicists using telescopes on the ground and in space have uncovered surprising changes in radiation emitted by an active galaxy. The picture that emerges from these first-ever ...

Fermi telescope finds gamma-ray galaxy surprises

Jul 14, 2009

Back in June 1991, just before the launch of NASA's Compton Gamma-Ray Observatory, astronomers knew of gamma rays from exactly one galaxy beyond our own. To their surprise and delight, the satellite captured ...

An Intriguing, Glowing Galaxy

May 14, 2009

A supermassive black hole may be responsible for the glowing appearance of galaxy 3C 305, located about 600 million light years away in the constellation Draco. Composite data from NASA’s Chandra X-ray Observatory ...

Recommended for you

Big black holes can block new stars

12 hours ago

Massive black holes spewing out radio-frequency-emitting particles at near-light speed can block formation of new stars in aging galaxies, a study has found.

POLARBEAR seeks cosmic answers in microwave polarization

12 hours ago

An international team of physicists has measured a subtle characteristic in the polarization of the cosmic microwave background radiation that will allow them to map the large-scale structure of the universe, ...

New radio telescope ready to probe

15 hours ago

Whirring back and forth on a turning turret, the white, 40-foot dish evokes the aura of movies such as "Golden Eye" or "Contact," but the University of Arizona team of scientists and engineers that commissioned ...

Exomoons Could Be Abundant Sources Of Habitability

Oct 20, 2014

With about 4,000 planet candidates from the Kepler Space Telescope data to analyze so far, astronomers are busy trying to figure out questions about habitability. What size planet could host life? How far ...

Partial solar eclipse over the U.S. on Thursday, Oct. 23

Oct 17, 2014

People in most of the continental United States will be in the shadow of the Moon on Thursday afternoon, Oct. 23, as a partial solar eclipse sweeps across the Earth. For people looking through sun-safe filters, from Los Angeles, ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

omatumr
2.3 / 5 (3) Dec 09, 2009
Mysterious

Now what could be the energy source that shoots a particle jet down the gamma-ray barrel?

Perhaps data in the chart of the nuclides contains the answer.

With kind regards,
Oliver K. Manuel
abhishekbt
5 / 5 (2) Dec 10, 2009
Sounds like the begining of an Action packed thriller!
With a little luck we could be able to decipher one such 'mystery' in our life time.
Parsec
5 / 5 (4) Dec 10, 2009
The energy source for most particle jets has been pretty well nailed down from the hundreds of symmetric jets we can observe around the universe. Black hole accretion disks convert up to 15% of the matter in them to energy from simple friction and emit a great deal of that in the form of narrowly focused jets located at the rotation poles.

For a supposedly educated person Oliver K. Manuel, you make an awful lot of really uneducated posts. I don't mind that, but you seem quite proud of your titles.

So where is the mystery here?