Chandra Sheds Light on Galaxy Collision

Mar 29, 2007
Chandra Sheds Light on Galaxy Collision
Image credit: X-ray: NASA/CXC/Univ. of Bristol/Worral et al.; Radio: NRAO/AUI/NSF

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 affect the galaxy and the environments around them.

One way such black holes shape their surroundings is by generating powerful jets of high-energy particles. The jets, which are bright in radio waves, have been seen to push around the hot gas that envelopes the galaxy. When this happens, astronomers can detect huge cavities and powerful shock fronts in the hot, X-ray emitting gas.

However, the opposite scenario is apparently unfolding in the galaxy known as 3C442A. X-ray data from NASA's Chandra X-ray Observatory and radio observations from the NSF's Very Large Array show that the hot gas (blue) in the middle of 3C442A is pushing apart the radio-bright gas (orange). The inner sections of the radio structure are sharp and concave, which is consistent with the idea that the X-ray bright gas is sweeping the radio-emitting gas aside. This is the first convincing evidence for such a role reversal.

A team of scientists, led by Diana Worrall of University of Bristol, UK, has studied this system and determined why the dynamics in 3C442A seem to be topsy-turvy. First, there are two galaxies near the middle of 3C442A which are in the process of merging. These two galaxies are on their second pass toward a collision, having already experienced a close encounter. The energy generated from this impending merger is heating the combined atmospheres from these two galaxies, causing them to shine brightly in X-rays and expand.

The researchers determined that the jets that had produced the lobes of radio-emitting gas are no longer active. The jets may have ceased at the time of, and possibly as a result of, the galaxy collision. Since the radio-emitting gas no longer has a power source, it is then at the mercy of the expanding hot gas and has been pushed aside.

Source: NASA

Explore further: Fermi satellite finds hints of starquakes in magnetar 'storm'

add to favorites email to friend print save as pdf

Related Stories

Comet Siding Spring whizzes past Mars

7 hours ago

A comet the size of a small mountain whizzed past Mars on Sunday, dazzling space enthusiasts with the once-in-a-million-years encounter.

Major breakthrough could help detoxify pollutants

12 hours ago

Scientists at The University of Manchester hope a major breakthrough could lead to more effective methods for detoxifying dangerous pollutants like PCBs and dioxins. The result is a culmination of 15 years of research and ...

Recommended for you

Big black holes can block new stars

19 hours ago

Massive black holes spewing out radio-frequency-emitting particles at near-light speed can block formation of new stars in aging galaxies, a study has found.

POLARBEAR seeks cosmic answers in microwave polarization

19 hours ago

An international team of physicists has measured a subtle characteristic in the polarization of the cosmic microwave background radiation that will allow them to map the large-scale structure of the universe, ...

New radio telescope ready to probe

22 hours ago

Whirring back and forth on a turning turret, the white, 40-foot dish evokes the aura of movies such as "Golden Eye" or "Contact," but the University of Arizona team of scientists and engineers that commissioned ...

Exomoons Could Be Abundant Sources Of Habitability

Oct 20, 2014

With about 4,000 planet candidates from the Kepler Space Telescope data to analyze so far, astronomers are busy trying to figure out questions about habitability. What size planet could host life? How far ...

User comments : 0