Research

Scientists watch new baby black holes

University Park, Pa. -- Scientists using NASA's Swift satellite say they have found newborn black holes, just seconds old, in a confused state of existence, sloppily gorging on material falling into them while somehow propelling other material away at great speeds.

These black holes are born in massive star explosions. An initial blast obliterates the star. Yet the chaotic black hole activity appears to re-energize the explosion again and again over the course of several minutes. This is a dramatically different view of star death, one that entails multiple explosive outbursts and not just a single bang, as previously thought.

"Stars are exploding two, three and sometimes four times in the first minutes following the initial explosion," said David Burrows, professor of astronomy and lead author on a paper appearing online today (Aug. 18, 2005) on Science Express and in the Sept. 9 issue of the journal Science. "First comes a blast of gamma rays followed by intense pulses of X-rays. The energies involved are much greater than anyone expected."

Scientists have seen this phenomenon in nearly half of the longer gamma-ray bursts detected by Swift so far. These gamma-ray bursts, the most powerful explosions known, are harbingers of a type of massive star explosion called a hypernova, bigger than a supernova. With the Swift satellite, scientists finally are able to see gamma-ray bursts within minutes after the trigger, instead of hours or days, and are now privy to newborn-black-hole activity. Until this latest Swift discovery, scientists had assumed a simple scenario of a single explosion followed by a graceful afterglow of the dying embers.

"The newly formed black hole immediately gets to work," said Peter Meszaros, who holds the Eberly family chair in the Eberly College of Science and is head of the Swift theory team. "We aren't clear on the details yet, but it appears to be messy. Matter is falling into the black hole, which releases a great amount of energy. Other matter gets blasted away from the black hole and flies out into the interstellar medium. This is by no means a smooth operation."

Several theories describe this newly discovered phenomenon and most point to the presence of a sloppy, newborn black hole. "None of this was realized before simply because we couldn't get to the scene of the explosion fast enough," said Neil Gehrels of NASA Goddard Space Flight Center, principal investigator of the Swift mission. "Swift has the unique ability to detect bursts and turn its X-ray and ultraviolet-optical telescopes to the explosion's embers within minutes. As such, Swift is detecting new burst details that might rewrite theory."

Swift carries three main instruments: the Burst Alert Telescope (BAT), the X-ray Telescope (XRT), and the Ultraviolet/Optical Telescope (UVOT). Today's announcement is based largely on XRT data. The XRT was built at Penn State with partners at the Brera Astronomical Observatory in Italy and the University of Leicester in England.

Swift, launched in November 2004, is a NASA mission in partnership with the Italian Space Agency and the Particle Physics and Astronomy Research Council, United Kingdom; and is managed by NASA Goddard. Penn State controls science and flight operations from the Mission Operations Center in University Park. The spacecraft was built in collaboration with national laboratories, universities and international partners, including Penn State; Los Alamos National Laboratory, New Mexico; Sonoma State University, Rohnert Park, Calif.; Mullard Space Science Laboratory in Dorking, Surrey, England; the University of Leicester, England; Brera Observatory in Milan; and ASI Science Data Center in Frascati, Italy.

For a video of a baby black hole, go to http://live.psu.edu/still_life/2005_08_18_swift/BabyBlackHole.mov online.

When a massive star runs out of fuel, it no longer has the energy to support its mass. View a video of this by clicking on the image above. Credit: NASA/GSFC/Dana BerryAll Rights Reserved.

Last Updated November 18, 2010