X-Ray Jets

Sep 07, 2010
A combined optical (green) and radio (red) image of an elliptical galaxy with jets of emission thought to be powered by a supermassive black hole at the galactic nucleus. SAO astronomers show that X-ray observations of such jets can also provide information on short time-scale activity. Credit: NRAO and AUI

(PhysOrg.com) -- The supermassive black holes that lie at the centers of galaxies can spawn tremendous bipolar jets of atomic particles.

These outflows, discovered at , are thought to be produced by matter accreting onto a hot disk around the black hole.

There are many types of galaxies and , but in the most dramatic cases the hot particles extend across hundreds of thousands of light-years, well beyond the visible boundaries of the galaxy, and move at speeds close to the .

The physical processes that drive these jets and cause them to radiate are among the important outstanding problems of modern astrophysics.

One of the problems in deciphering how the jet mechanisms operate, and how they interact with the environment near the black hole nuclei, is the comparatively gradual way that radio emission responds to changes. As a result, differences that may occur along the jet (or at different times in the same location) appear blurred together when viewed at radio wavelengths.

X-rays are also emitted from these jets, but unlike radio emission they respond very quickly to changes. SAO astronomers and associates Diana Worrall, Mark Birkenshaw, Andreas Zezas and Pepi Fabbiano, together with three colleagues, used the Chandra X-Ray Observatory to measure the X-ray emission from jets in the galaxy 3C270.

By comparing the emission from both sides of the jets (and their environments) with the corresponding , they were able to reach several important conclusions. The first is that bright knots along the jet are driven by the effects of local magnetic fields. Another is that changes in the jets seem to have taken place during comparatively short timescales -- only tens or hundreds of thousands of years.

The exact causes, however, are not yet clear. The results suggest that X-ray observations might be the most powerful way to probe episodic activity around giant black holes.

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

add to favorites email to friend print save as pdf

Related Stories

X-Ray Jets from Galaxies

Oct 19, 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 ...

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 ...

Black Hole Gets Jerked Around -- Twice

Jul 21, 2010

(PhysOrg.com) -- Scientists have found evidence that a giant black hole has been jerked around twice, causing its spin axis to point in a different direction from before. This discovery, made with new data ...

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 ...

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 : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

omatumr
3 / 5 (1) Sep 08, 2010
Jets from cosmic objects are indeed intriguing.

Neutron stars, "black holes", and many supernova explosions have an axial direction (e.g., SN 1987A).

As I recall material that leaves the polar region of the Sun moves faster than that departs in the equatorial plane.

That is a mystery that awaits an explanation.

With kind regards,
Oliver K. Manuel