X-Ray Jets from Galaxies

Oct 19, 2009
A false-color image of the nuclear region of the galaxy NGC 4151, showing a region about 1000 light-years across. Blue is radio emission, green is optical emission from ionized oxygen as seen with the Hubble Space Telescope, and red is X-ray emission as seen by the Chandra X-ray Observatory. The X-ray data represent the first such fine-scale X-ray imaging of an extreme galaxy nucleus. Credit: NASA/Chandra X-ray Observatory/Hubble Space Telescope, and Wang et al., 2009

(PhysOrg.com) -- Some dramatic galaxies eject gigantic, collimated jets of ionized gas millions of light-years long, powered by the massive black holes at their centers. The ionized jets are detected at radio wavelengths, and sometimes in the optical, but most of these active galactic nuclei also produce X-rays in the vicinities of the nuclei.

The X-ray emission helps astronomers to determine the physical processes responsible for the jets, as well as the nature of the , their environment, and the properties of the themselves. In most with radio jets, however, the X-ray studies are difficult because the emission is faint and the galaxies are too far away to easily image them in X-rays.

A team of six CfA astronomers led by Junfeng Wang, together with one of their colleagues, used the Chandra X-ray Observatory to study the galaxy NGC 4151, at about 40 million light-years away one of the closest . Its radio jet is small, only about 700 light-years long, making this galaxy a good example of the more conventional jet sources. Moreover, the has provided detailed optical images of the inner regions. The scientists' new observations are the first very deep X-ray images of this nucleus.

The astronomers were able to compare the detailed morphology of the X-ray emitting gas with that of the ionized light seen in the optical, comparing for example the knots of activity along the jets. They find that the overall physical conditions of these knots are the same independent of the distance of a knot from the black hole.

The scientists conclude as a result that one of the most commonly advanced theories about the emission, one that relies on magnetic fields, is not supported, at least in this class of galaxy. Instead, the new results tend to indicate that an outflowing wind is slamming into clouds of gas in the local environment, and that these interactions are generating the X-rays. The results help to explain how and why the jets in these more modest sources compare to those in the more extreme examples, and thereby also lend credibility to our general understanding of these amazing cosmic beacons.

Provided by Harvard-Smithsonian Center for Astrophysics (news : web)

Explore further: First potentially habitable Earth-sized planet confirmed: It may have liquid water

add to favorites email to friend print save as pdf

Related Stories

Chandra Sheds Light on Galaxy Collision

Mar 29, 2007

Astronomers think that there are enormous black holes at the centers of most, if not all, galaxies. These black holes, which can be millions or even billions of times more massive than the Sun, can greatly ...

An Intriguing, Glowing Galaxy

May 14, 2009

A supermassive black hole may be responsible for the glowing appearance of galaxy 3C 305, located about 600 million light years away in the constellation Draco. Composite data from NASA’s Chandra X-ray Observatory ...

Chandra Shows Shocking Impact of Galaxy Jet

Apr 22, 2009

(PhysOrg.com) -- A survey by the Chandra X-ray observatory has revealed in detail, for the first time, the effects of a shock wave blasted through a galaxy by powerful jets of plasma emanating from a supermassive ...

Neutron Stars Join the Black-Hole Jet Set

Feb 04, 2008

A team of astronomers has discovered a neutron star emitting an extended stream of powerful X rays, marking the first time such an extended X-ray jet has been detected originating from any class of object ...

Recommended for you

A sharp eye on Southern binary stars

6 hours ago

Unlike our sun, with its retinue of orbiting planets, many stars in the sky orbit around a second star. These binary stars, with orbital periods ranging from days to centuries, have long been the primary ...

Hubble image: A cross-section of the universe

7 hours ago

An image of a galaxy cluster taken by the NASA/ESA Hubble Space Telescope gives a remarkable cross-section of the Universe, showing objects at different distances and stages in cosmic history. They range ...

Cosmologists weigh cosmic filaments and voids

10 hours ago

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

omatumr
1 / 5 (1) Oct 19, 2009
No, not powered by black holes.

Powered by repulsive interactions between neutrons in massive neutron stars.

See: "Neutron repulsion confirmed as energy source", Journal of Fusion Energy 20 (2003) 197-201 or "The Sun is a plasma diffuser that sorts atoms by mass", Physics of Atomic Nuclei 69 (2006) 1847-1856; Yadernaya Fizika 69 (November 2006) number 11.

With kind regards,
Oliver K. Manuel

More news stories

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...

Hubble image: A cross-section of the universe

An image of a galaxy cluster taken by the NASA/ESA Hubble Space Telescope gives a remarkable cross-section of the Universe, showing objects at different distances and stages in cosmic history. They range ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Researchers discover target for treating dengue fever

Two recent papers by a University of Colorado School of Medicine researcher and colleagues may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other ...