Subscribe free to our newsletters via your
. 24/7 Space News .




TIME AND SPACE
Texas-Size Computer Finds Most Massive Black Hole In Galaxy M87
by Staff Writers
Pasadena CA (SPX) Jun 09, 2009


The illustration shows the relationship between the mass of a galaxy's central black hole and the mass of its central bulge. The new higher mass Gebhardt and Thomas computer modeled for M87's black hole, 6.4 billion solar masses, could change this relationship. They used a more complete computer model than previous work. This may mean that the black holes in all nearby massive galaxies are more massive than we think, signaling a change in our understanding of the relationship between a black hole and its surrounding galaxy. Credit: Tim Jones/UT-Austin after K. Cordes and S. Brown (STScI). For a larger version of this image please go here.

Astronomers Karl Gebhardt (The University of Texas at Austin) and Jens Thomas (Max Planck Institute for Extraterrestrial Physics) have used new computer modeling techniques to discover that the black hole at the heart of M87, one the largest nearby giant galaxies, is two to three times more massive than previously thought.

Weighing in at 6.4 billion times the Sun's mass, it is the most massive black hole yet measured with a robust technique, and suggests that the accepted black hole masses in nearby large galaxies may be off by similar amounts. This has consequences for theories of how galaxies form and grow, and might even solve a long-standing astronomical paradox.

Gebhardt will detail these results in a press conference June 8 at 12 Noon PDT at the 214th meeting of the American Astronomical Society in Pasadena, Calif. They will be published later this summer in The Astrophysical Journal, in a paper by Gebhardt and Thomas.

To try to understand how galaxies form and grow, astronomers need start with basic census information about today's galaxies. What are they made of? How big are they? How much do they weigh? Astronomers measure this last category, galaxy mass, by clocking the speed of stars orbiting within the galaxy.

Studies of the total mass are important, Thomas said, but "the crucial point is to determine whether the mass is in the black hole, the stars, or the dark halo. You have to run a sophisticated model to be able to discover which is which. The more components you have, the more complicated the model is."

To model M87, Gebhardt and Thomas used one of the world's most powerful supercomputers, the Lonestar system at The University of Texas at Austin's Texas Advanced Computing Center. Lonestar is a Dell Linux cluster with 5,840 processing cores and can perform 62 trillion floating-point operations per second. (Today's top-of-the-line laptop computer has two cores and can perform up to 10 billion floating-point operations per second.)

Gebhardt and Thomas' model of M87 was more complicated than previous models of the galaxy, because in addition to modeling its stars and black hole, it takes into account the galaxy's "dark halo," a spherical region surrounding a galaxy that extends beyond its main visible structure, containing the galaxy's mysterious "dark matter."

"In the past, we have always considered the dark halo to be significant, but we did not have the computing resources to explore it as well," Gebhardt said. "We were only able to use stars and black holes before. Toss in the dark halo, it becomes too computationally expensive, you have to go to supercomputers."

The Lonestar result was a mass for M87's black hole several times what previous models have found. "We did not expect it at all," Gebhardt said. He and Thomas simply wanted to test their model on "the most important galaxy out there," he said.

Extremely massive and conveniently nearby (in astronomical terms), M87 was one of the first galaxies suggested to harbor a central black hole nearly three decades ago.

It also has an active jet shooting light out of the galaxy's core as matter swirls closer to the black hole, allowing astronomers to study the process by which black holes attract matter. All of these factors make M87 the "the anchor for supermassive black hole studies," Gebhardt said.

These new results for M87, together with hints from other recent studies and his own recent telescope observations (publications in preparation), lead him to suspect that all black hole masses for the most massive galaxies are underestimated.

That conclusion "is important for how black holes relate to galaxies," Thomas said. "If you change the mass of the black hole, you change how the black hole relates to the galaxy." There is a tight relation between the galaxy and its black hole which had allowed researchers to probe the physics of how galaxies grow over cosmic time. Increasing the black hole masses in the most massive galaxies will cause this relation to be re-evaluated.

Higher masses for black holes in nearby galaxies also could solve a paradox concerning the masses of quasars - active black holes at the centers of extremely distant galaxies, seen at a much earlier cosmic epoch. Quasars shine brightly as the material spirals in, giving off copious radiation before crossing the event horizon (the region beyond which nothing - not even light - can escape).

"There is a long-standing problem in that quasar black hole masses were very large - 10 billion solar masses," Gebhardt said. "But in local galaxies, we never saw black holes that massive, not nearly. The suspicion was before that the quasar masses were wrong," he said. But "if we increase the mass of M87 two or three times, the problem almost goes away."

The conclusions are model-based, but Gebhardt also has made new telescope observations of M87 and other galaxies using new powerful instruments on the Gemini North Telescope and the European Southern Observatory's Very Large Telescope. He said these data, which will be submitted for publication soon, support the current model-based conclusions about black hole mass.

For future telescope observations of galactic dark haloes, Gebhardt notes that a relatively new instrument at The University of Texas at Austin's McDonald Observatory is perfect.

"If you need to study the halo to get the black hole mass, there's no better instrument than VIRUS-P," he said. The instrument is a spectrograph. It separates the light from astronomical objects into its component wavelengths, creating a signature that can be read to find out an object's distance, speed, motion, temperature, and more.

VIRUS-P is good for halo studies because it can take spectra over a very large area of sky, allowing astronomers to reach the very low light levels at large distances from the galaxy center where the dark halo is dominant. It is a prototype, built to test technology going into the larger VIRUS spectrograph for the forthcoming Hobby-Eberly Telescope Dark Energy Experiment (HETDEX).

.


Related Links
The University of Texas at Austin
Understanding Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TIME AND SPACE
Ghost Remains After Black Hole Eruption
Boston MA (SPX) May 29, 2009
NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The ... read more


TIME AND SPACE
NASA Announces Winners In Lunar Art Contest

New Tool To Visualize Past, Future Lunar Eclipses

China Considering Manned Lunar Landing In 2025-2030

The Next Moon Missions

TIME AND SPACE
Life Support Pilot Plant Paves The Way To Moon And Beyond

Mars Reconnaissance Orbiter In Safe Mode After Reboot

Scarce Shelter On Mars

Evidence For Liquid Water On Early Frozen Mars

TIME AND SPACE
A New Way To Measure Cosmic Distances

New Cleaning Protocol For Future Search For Life Missions

Astronauts test new space suits

To The Moon, By Way Of MIT

TIME AND SPACE
China to launch Mars space probe

China To Launch First Mars Probe In Second Half Of 2009

China Launches Yaogan VI Remote-Sensing Satellite

China Able To Send Man To Moon Around 2020

TIME AND SPACE
ISS Astronauts Complete Spacewalk, Test New Russian Spacesuits

Space station crew doubles to six for first time

International Space Station Doubles Crew To Six

ISS To Welcome First Full Crew

TIME AND SPACE
Stat X Fire Suppression System Selected For Giant Crawlers

Arianespace Receives Ariane 5 For Its TerreStar-1 Mission

SPACEX And ATSB Announce New Launch Date For Razaksat Satellite

Brazil Launches Rocket To Test Launching Base

TIME AND SPACE
Planet-Hunting Method Succeeds At Last

New Method For Finding Alien Oceans

Let The Planet Hunt Begin

The Crowded Universe

TIME AND SPACE
Space Traffic Management In The Earth 21st Century

Integral Systems To Provide KOREASAT-6 Satellite Command And Control

Raytheon Hyperspectral Imaging Sensor Activated For Year-Long Mission

Planck Satellite Manoeuvre Aims At L2 Arrival




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement