Wall Divides East and West Sides of Cosmic Metropolis

Jan 27, 2009
Credits: X-ray: NASA/CXC/CfA/R. Tuellmann et al.; Optical: NASA/AURA/ STScI

(PhysOrg.com) -- A new study unveils NGC 604, the largest region of star formation in the nearby galaxy M33, in its first deep, high-resolution view in X- rays. This composite image from Chandra X-ray Observatory data (colored blue), combined with optical light data from the Hubble Space Telescope (red and green), shows a divided neighborhood where some 200 hot, young, massive stars reside.

Throughout the cosmic metropolis, giant bubbles in the cool dust and warm gas are filled with diffuse, multi-million degree gas that emits X-rays. Scientists think these bubbles are generated and heated to X- ray temperatures when powerful stellar winds from the young massive stars collide and push aside the surrounding gas and dust. So, the vacated areas are immediately repopulated with the hotter material seen by Chandra.

However, there is a difference between the two sides of this bifurcated stellar city. (See annotated image for the location of the "wall".) On the western (right) side, the amount of hot gas found in the bubbles corresponds to about 4300 times the mass of the sun. This value and the brightness of the gas in X-rays imply that the western part of NGC 604 is entirely powered by winds from the 200 hot massive stars.

This result is interesting because previous modeling of other bubbles usually predicted them to be fainter than observed, so that additional heating from supernova remnants is required. The implication is that in this area of NGC 604, none or very few of the massive stars must have exploded as supernovas.

The situation is different on the eastern (left) side of NGC 604. On this side, the X-ray gas contains 1750 times the mass of the sun and winds from young stars cannot explain the brightness of the X-ray emission. The bubbles on this side appear to be much older and were likely created and powered by young stars and supernovas in the past.

A similar separation between east and west is seen in the optical results. This implies that a massive wall of gas shields the relatively quiet region in the east from the active star formation in the west.

This study was led by Ralph Tuellmann of the Harvard Smithsonian Center for Astrophysics and was part of a very deep, 16-day long observation of M33 called the Chandra ACIS Survey of M33, or ChASeM33.

Provided by NASA

Explore further: How baryon acoustic oscillation reveals the expansion of the universe

add to favorites email to friend print save as pdf

Related Stories

How do planets form?

Sep 09, 2014

We have a pretty good idea of how planets form around stars. We know that dust is formed from the remnants of supernovae, that protoplanetary disks of dust form around young stars, and that dust grains can ...

Recommended for you

The Great Cold Spot in the cosmic microwave background

Sep 19, 2014

The cosmic microwave background (CMB) is the thermal afterglow of the primordial fireball we call the big bang. One of the striking features of the CMB is how remarkably uniform it is. Still, there are some ...

Mystery of rare five-hour space explosion explained

Sep 17, 2014

Next week in St. Petersburg, Russia, scientists on an international team that includes Penn State University astronomers will present a paper that provides a simple explanation for mysterious ultra-long gamma-ray ...

Glowing galaxies in telescopic timelapse

Sep 17, 2014

We often speak of the discoveries and data flowing from astronomical observatories, which makes it easy to forget the cool factor. Think of it—huge telescopes are probing the universe under crystal-clear ...

Violent origins of disc galaxies probed by ALMA

Sep 17, 2014

For decades scientists have believed that galaxy mergers usually result in the formation of elliptical galaxies. Now, for the the first time, researchers using the Atacama Large Millimeter/sub-millimeter ...

User comments : 6

Adjust slider to filter visible comments by rank

Display comments: newest first

theophys
not rated yet Jan 27, 2009
Mr. Gorbachev, tear down that cosmic wall!
I know it has basically no relevence to the article, but how often do you get a chance to use a Reagan quote in reference to astrophysics?
Thecis
1 / 5 (1) Jan 28, 2009
hahaha.
You must be ashamed of yourself. A good quote can do wonders but to use a phrase said by an american actor that got lucky?? ;-)
LuckyBrandon
3 / 5 (2) Jan 28, 2009
do you think those WIMPs can jump the wall?
theophys
1 / 5 (1) Jan 29, 2009
hahaha.
You must be ashamed of yourself. A good quote can do wonders but to use a phrase said by an american actor that got lucky?? ;-)

It's a good phrase, even if the president who said it kinda sucked.
jonnyboy
1 / 5 (1) Feb 01, 2009
theo, whenever you get the urge to add a comment, don't!!!!

Pull the plug instead
theophys
not rated yet Feb 02, 2009
Looks like we have a Reagan fan. Or a hater of corny jokes.