NASA's WISE Mission Sees Skies Ablaze With Blazars

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News release: 2012-103 April 12, 2012

NASA's WISE Mission Sees Skies Ablaze With Blazars

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2012-103&cid=release_2012-103

PASADENA, Calif. – Astronomers are actively hunting a class of supermassive black holes
throughout the universe called blazars thanks to data collected by NASA's Wide-field Infrared
Survey Explorer (WISE). The mission has revealed more than 200 blazars and has the potential to
find thousands more.

Blazars are among the most energetic objects in the universe. They consist of supermassive black
holes actively "feeding," or pulling matter onto them, at the cores of giant galaxies. As the matter is
dragged toward the supermassive hole, some of the energy is released in the form of jets traveling at
nearly the speed of light. Blazars are unique because their jets are pointed directly at us.

"Blazars are extremely rare because it's not too often that a supermassive black hole's jet happens to
point towards Earth," said Franceso Massaro of the Kavli Institute for Particle Astrophysics and
Cosmology near Palo Alto, Calif., and principal investigator of the research, published in a series of
papers in the Astrophysical Journal. "We came up with a crazy idea to use WISE's infrared
observations, which are typically associated with lower-energy phenomena, to spot high-energy
blazars, and it worked better than we hoped."

The findings ultimately will help researchers understand the extreme physics behind super-fast jets
and the evolution of supermassive black holes in the early universe.

WISE surveyed the entire celestial sky in infrared light in 2010, creating a catalog of hundreds of
millions of objects of all types. Its first batch of data was released to the larger astronomy community
in April 2011 and the full-sky data were released last month.

Massaro and his team used the first batch of data, covering more than one-half the sky, to test their
idea that WISE could identify blazars. Astronomers often use infrared data to look for the weak heat
signatures of cooler objects. Blazars are not cool; they are scorching hot and glow with the highest-
energy type of light, called gamma rays. However, they also give off a specific infrared signature
when particles in their jets are accelerated to almost the speed of light.

One of the reasons the team wants to find new blazars is to help identify mysterious spots in the sky
sizzling with high-energy gamma rays, many of which are suspected to be blazars. NASA's Fermi
mission has identified hundreds of these spots, but other telescopes are needed to narrow in on the
source of the gamma rays.

Sifting through the early WISE catalog, the astronomers looked for the infrared signatures of blazars
at the locations of more than 300 gamma-ray sources that remain mysterious. The researchers were
able to show that a little more than half of the sources are most likely blazars.

"This is a significant step toward unveiling the mystery of the many bright gamma-ray sources that
are still of unknown origin," said Raffaele D'Abrusco, a co-author of the papers from Harvard
Smithsonian Center for Astrophysics in Cambridge, Mass. "WISE's infrared vision is actually helping
us understand what's happening in the gamma-ray sky."

The team also used WISE images to identify more than 50 additional blazar candidates and observed
more than 1,000 previously discovered blazars. According to Massaro, the new technique, when
applied directly to WISE's full-sky catalog, has the potential to uncover thousands more.

"We had no idea when we were building WISE that it would turn out to yield a blazar gold mine,"
said Peter Eisenhardt, WISE project scientist at NASA's Jet Propulsion Laboratory in Pasadena,
Calif., who is not associated with the new studies. "That's the beauty of an all-sky survey. You can
explore the nature of just about any phenomenon in the universe."

Other authors include: A. Paggi and H.A. Smith of Harvard's Smithsonian Astrophysical
Observatory; G. Tosti of the University of Perugia, Italy; M. Ajello of Stanford University, Stanford,
Calif.; J.E. Grindlay of the Harvard College Observatory, Cambridge, Mass; and D. Gasparrini of the
Italian Space Agency, Science Data Center, Italy.

The Kavli Institute for Particle Astrophysics and Cosmology is a joint institute of Stanford University
and SLAC National Accelerator Laboratory in Menlo Park, Calif.

JPL manages and operates WISE for NASA's Science Mission Directorate in Washington. The
principal investigator for WISE, Edward Wright, is at UCLA. The mission was competitively
selected under NASA's Explorers Program, managed by the Goddard Space Flight Center in
Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah,
and the spacecraft was built by Ball Aerospace & Technologies Corp. in Boulder, Colo. Science
operations and data processing and archiving take place at the Infrared Processing and Analysis
Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and
http://jpl.nasa.gov/wise .

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