Andromeda galaxy pops up ultraluminous X-ray sources

Feb 27, 2012 By Francis Reddy
This image from Swift's X-Ray Telescope captures both of the known ULXs in M31. The first, dubbed CXOM31 J004253.1+411422, was discovered with NASA's Chandra X-ray Observatory on Dec. 17, 2009, and appears to be a stellar-mass black hole. The other, named XMMU J004243.6+412519, was discovered just last month, on Jan. 15, by the European Space Agency's XMM-Newton spacecraft. Credit: NASA/Swift/Stefan Immler

(PhysOrg.com) -- Researchers using NASA's Chandra X-ray Observatory, Hubble Space Telescope, Swift Gamma-ray Burst Explorer and the European Space Agency's XMM-Newton Observatory have been studying an object known as an ultraluminous X-ray source -- ULX, for short -- in the neighboring Andromeda galaxy (M31). Scientists have long debated the nature of these super-bright X-ray sources, and Chandra's 2009 discovery of a nearby ULX in Andromeda sparked intense interest.

Why are these sources so bright in X-rays? Are they normal stellar-mass black holes gorging on unusually large amounts of gas? Or are they long-sought "intermediate mass" black holes, dozens of times more massive than their stellar counterparts but smaller than the monster black holes found in the centers of most galaxies?

The locations of two M31 ULXs are shown on this optical image of our galactic neighbor. M31 lies 2.5 million light-years away in the constellation Andromeda and is the nearest large spiral galaxy to our own. Under a clear, dark sky, it can be seen as a misty patch with the naked eye. Credit: NASA/Swift; background: Bill Schoening, Vanessa Harvey/REU program/NOAO/AURA/NSF

Although astronomers have been studying M31 extensively by X-ray satellites since the 1980s, no ULX had been seen there until 2009.

Adding to the intrigue is a new ULX in M31, discovered just last month by XMM-Newton. Previously, M31's lack of ULXs had suggested to some scientists that these intense beacons didn't form in tranquil spiral galaxies like Andromeda and our own home galaxy, the Milky Way. The appearance of two ULXs within such a relatively short period is truly remarkable.

The Chandra-discovered ULX, dubbed CXOM31 J004253.1+411422, is now the subject of two studies published in the journals and the . These latest reports suggest that this ULX is a stellar-mass black hole, but one that's consuming great amounts of matter.

Explore further: Image: NGC 6872 in the constellation of Pavo

More information: Read more at www.physorg.com/news/2012-02-s… meda-black-hole.html

add to favorites email to friend print save as pdf

Related Stories

Massive Black Hole Implicated in Stellar Destruction

Jan 04, 2010

(PhysOrg.com) -- New results from NASA's Chandra X-ray Observatory and the Magellan telescopes suggest that a dense stellar remnant has been ripped apart by a black hole a thousand times as massive as the ...

Nearby black hole is feeble and unpredictable

May 25, 2010

For over 10 years, NASA's Chandra X-ray Observatory has repeatedly observed the Andromeda Galaxy for a combined total of nearly one million seconds. This unique data set has given astronomers an unprecedented ...

Black hole came from a shredded galaxy

Feb 15, 2012

(PhysOrg.com) -- Astronomers using NASA's Hubble Space Telescope have found a cluster of young, blue stars encircling the first intermediate-mass black hole ever discovered. The presence of the star cluster ...

The murmur of a monster

Feb 28, 2011

The Andromeda galaxy is the nearest large galaxy to our Milky Way. Like the Milky Way, it has a spiral-arm structure with a massive black hole at its nucleus. Unlike the Milky Way, however, its black hole ...

Recommended for you

Image: NGC 6872 in the constellation of Pavo

13 hours ago

This picture, taken by the NASA/ESA Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2), shows a galaxy known as NGC 6872 in the constellation of Pavo (The Peacock). Its unusual shape is caused ...

Measuring the proper motion of a galaxy

14 hours ago

The motion of a star relative to us can be determined by measuring two quantities, radial motion and proper motion. Radial motion is the motion of a star along our line of sight. That is, motion directly ...

Gravitational waves according to Planck

Sep 22, 2014

Scientists of the Planck collaboration, and in particular the Trieste team, have conducted a series of in-depth checks on the discovery recently publicized by the Antarctic Observatory, which announced last ...

Infant solar system shows signs of windy weather

Sep 22, 2014

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have observed what may be the first-ever signs of windy weather around a T Tauri star, an infant analog of our own Sun. This may help ...

Finding hints of gravitational waves in the stars

Sep 22, 2014

Scientists have shown how gravitational waves—invisible ripples in the fabric of space and time that propagate through the universe—might be "seen" by looking at the stars. The new model proposes that ...

How gamma ray telescopes work

Sep 22, 2014

Yesterday I talked about the detection of gamma ray bursts, intense blasts of gamma rays that occasionally appear in distant galaxies. Gamma ray bursts were only detected when gamma ray satellites were put ...

User comments : 0