The murmur of a monster

Feb 28, 2011
An image of the Andromeda Galaxy as seen at infrared (red) and X-rays (blue) wavelengths. A new study of the X-ray emission from the region around the supermassive black hole at the nucleus finds flaring activity - the first time such processes, analogous to those in the Milky Way, have been seen elsewhere. Credit: ESA Herschel, XMM-Newton

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 is remarkable in size - about 30 times bigger than the one in our galaxy, or nearly one hundred million solar masses. It is also unusually passive: similar supermassive black holes in more distant galaxies are often surrounded by accretion disks that emit bright X-rays and generate powerful jets of charged particles. Andromeda lacks both.

Astronomers want to understand why the nucleus of Andromeda is so quiescent, both to model its black hole behavior, and also to try to understand why distant are so different; did the once pass through a similar phase?

The Milky Way's black hole is also quiescent compared to these other galaxies, but it is curious in that it does flare up occasionally at X-ray, infrared and , sometimes increasing its brightness by a factor of ten or one hundred over short times. It had been thought that perhaps the Milky Way's black hole environment was different in a special way, perhaps somehow related to larger question of the extreme emission in distant systems.

CfA astronomers Zhiyuan Li, Michael Garcia, Bill Forman, Christine Jones, Ralph Kraft, Dharam Val, and Steve Murray carefully re-examined a decade's worth of Chandra X-ray Observatory observations of Andromeda, with a remarkable result. They found that although the nucleus was passive from 1999 until 2005, in 2006 it increased its X-ray luminosity by forty times, and remains bright and variable today. The team proposes future coordinated X-ray and radio studies. The results are important for showing that the Milky Way's black hole is not unique (at least in regard to flaring), and providing a step towards a better understanding of what goes on in other galactic nuclei with black holes.

Explore further: Astronomical forensics uncover planetary disks in Hubble archive

add to favorites email to friend print save as pdf

Related Stories

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 ...

How do supermassive black holes get so big?

Apr 26, 2010

(PhysOrg.com) -- At the center of most galaxies lie supermassive black holes that can grow to become more than a billion times larger than our Sun. However, astrophysicists don’t fully understand the formation ...

Giant gamma ray bubbles in our galaxy

Nov 19, 2010

(PhysOrg.com) -- Gamma rays are the most energetic form of light, typically about one hundred billion times as energetic as optical light.

How often do giant black holes become hyperactive?

Dec 20, 2010

(PhysOrg.com) -- A new study from NASA's Chandra X-ray Observatory tells scientists how often the biggest black holes have been active over the last few billion years. This discovery clarifies how supermassive ...

Recommended for you

Professional and amateur astronomers join forces

11 hours ago

(Phys.org) —Long before the term "citizen science" was coined, the field of astronomy has benefited from countless men and women who study the sky in their spare time. These amateur astronomers devote hours ...

A star's early chemistry shapes life-friendly atmospheres

Apr 23, 2014

Born in a disc of gas and rubble, planets eventually come together as larger and larger pieces of dust and rock stick together. They may be hundreds of light-years away from us, but astronomers can nevertheless ...

User comments : 9

Adjust slider to filter visible comments by rank

Display comments: newest first

Tuxford
1 / 5 (7) Feb 28, 2011
'Grey' Black Holes grow over time from nucleating new matter within their extremely (but finite) dense cores. They also generate new energy for our universe therein via photon blue-shifting (Pioneer Anomoly) according to LaViolette. The genic energy produced in nonlinear proportion to mass density therein eventually opposes the gravitic collapse pressure, leading to a oscillatory but stable condition, with the occasional outbursts observed. Stellar pulsation is another effect on a smaller scale. AGN's are an effect on a larger scale.

I find it silly to insist all these massive black holes are powered by accretion. Note the concentric ring structure. Cyclic outbursts of new matter. Stars moving radially outward in Milky Way?
Tuxford
1.5 / 5 (8) Feb 28, 2011
Taken together with the recent news (Feb. 15) that younger stars populate a disk near the center of M31, should not one conclude that this inside-out growth model must be now considered? That the Grey Black-Hole is much larger than our own core star means that M31 is growing more rapidly, with more frequent outbursts (Fermi Bubbles). Likely life developing near the center of M31 is more problematic than in our own galaxy.

I hope to hear the results of a survey correlating galaxy size, age, and structure to it's black hole mass and activity. Can accretion easily explain this core star variability over such short time scales?
omatumr
1 / 5 (5) Feb 28, 2011
Taken together with the recent news (Feb. 15) that younger stars populate a disk near the center of M31, should not one conclude that this inside-out growth model must be now considered?


Your point is valid.

The solar system was produced by inside-out growth from the Sun 5 Gyr ago.

Neutron repulsion causes large massive neutron stars to fragment into galaxies of stars, and smaller neutron stars at the cores of ordinary stars to fragment into planets.

See the evidence for neutron repulsion in this video:

youtube.com/my_videos_insight?v=sXNyLYSiPO0

Or study the data in this manuscript on neutron repulsion:

arxiv.org/pdf/1102.1499v1

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo


omatumr
1 / 5 (5) Mar 01, 2011
The monster at the center of the Andromeda Galaxy is not a black hole, but a massive neutron star that may be described by the wormhole model of V. Dzhunushaliev, V. Folomeev, B. Kleihaus, J. Kunz

"A Star Harbouring a Wormhole at its Center"

arxiv.org/pdf/1102.4454v1

See the PhysOrg news story:
"Scientists investigate the possibility of wormholes between stars"

physorg.com/news/2011-02-scientists-possibility-wormholes-stars.
vidyunmaya
1 / 5 (3) Mar 01, 2011
Sub:See Phenomena as it unravels-Andromeda
One sees a beutiful Flower Pattern and needs to balance itself.increasing its brightness by a factor of ten or one hundred over short times.
The bottom end -Milky way arguments cannot be valid-as this Andromeda has overcome Energy Retrieval state from Galactic Milkyway Center
Transcend to a new Phenomena onset-it becomes an eye opener to the Universe in dimensions-See Cosmology Vedas Interlinks-Books-Projections
Tamasoma Jyotirgamaya-Lead Kindly Light-Search beyond Dark Matter and then to Heart and Center of Universe
See-www[dot]scribd [dot]com-doc-17291010/COSMOLOGY-VEDAS-INTERLINKSBOOKS-INFORMATION
Burnerjack
not rated yet Mar 01, 2011
I'm confused. Black holes have event horizons yet give off EM radiation periodically? Doesn't that violate the definition of "Black hole"?
d_robison
5 / 5 (4) Mar 01, 2011
The monster at the center of the Andromeda Galaxy is not a black hole, but a massive neutron star that may be described by the wormhole model of V. Dzhunushaliev, V. Folomeev, B. Kleihaus, J. Kunz

"A Star Harbouring a Wormhole at its Center"

arxiv.org/pdf/1102.4454v1

See the PhysOrg news story:
"Scientists investigate the possibility of wormholes between stars"

physorg.com/news/2011-02-scientists-possibility-wormholes-stars.


It seems that every celestial body will soon become a neutron star...
Surely as a scientist you can discern between religion and actual science? Also the center of the Milky Way could not be a neutron star, as after the neutron star has accumulated enough material it would probably become unstable. This paper has some information on the subject, "Compact Stellar X-ray Sources (2006). Eds. Lewin and van der Klis, Cambridge University"
omatumr
1 / 5 (6) Mar 01, 2011
I'm confused. Black holes have event horizons yet give off EM radiation periodically? Doesn't that violate the definition of "Black hole"?


Yes, it does seem to violate the very definition of a black hole, despite all the hand-waving.
DavidMcC
5 / 5 (1) Apr 20, 2011
Hmm, I don't see a single good science post here. However, Burnerjack's question is good. The answer is that the flares come from material spiralling in to the BH under its gravity. Outside the event horizon of a feeding BH, there's a lot of X-ray generation as a result. Red-shifting only becomes severe very close in.

More news stories

Habitable exoplanets are bad news for humanity

Last week, scientists announced the discovery of Kepler-186f, a planet 492 light years away in the Cygnus constellation. Kepler-186f is special because it marks the first planet almost exactly the same size as Earth ...

Professional and amateur astronomers join forces

(Phys.org) —Long before the term "citizen science" was coined, the field of astronomy has benefited from countless men and women who study the sky in their spare time. These amateur astronomers devote hours ...

Kazakh satellite to be launched into orbit

Kazakhstan's first-ever Earth observation satellite is to be fired into orbit next week from the European spaceport in Kourou in French Guiana, launch company Arianespace said.