Featured Research

from universities, journals, and other organizations

Dwarf galaxy caught ramming into a large spiral

Date:
August 14, 2013
Source:
Chandra X-ray Observatory
Summary:
Astronomers have observed a massive cloud of multimillion-degree gas in a galaxy about 60 million light years from Earth. The hot gas cloud is likely caused by a collision between a dwarf galaxy and a much larger galaxy called NGC 1232.

Observations with Chandra have revealed a giant cloud of superheated gas in a galaxy about 60 million light years from Earth.
Credit: X-ray: NASA/CXC/Huntingdon Inst. for X-ray Astronomy/G.Garmire, Optical: ESO/VLT

Observations with NASA's Chandra X-ray Observatory have revealed a massive cloud of multimillion-degree gas in a galaxy about 60 million light years from Earth. The hot gas cloud is likely caused by a collision between a dwarf galaxy and a much larger galaxy called NGC 1232. If confirmed, this discovery would mark the first time such a collision has been detected only in X-rays, and could have implications for understanding how galaxies grow through similar collisions.

Related Articles


An image combining X-rays and optical light shows the scene of this collision. The impact between the dwarf galaxy and the spiral galaxy caused a shock wave − akin to a sonic boom on Earth -- that generated hot gas with a temperature of about 6 million degrees. Chandra X-ray data, in purple, show the hot gas has a comet-like appearance, caused by the motion of the dwarf galaxy. Optical data from the European Southern Observatory's Very Large Telescope reveal the spiral galaxy in blue and white. X-ray point sources have been removed from this image to emphasize the diffuse emission.

Near the head of the comet-shaped X-ray emission (mouse over the image for the location) is a region containing several very optically bright stars and enhanced X-ray emission. Star formation may have been triggered by the shock wave, producing bright, massive stars. In that case X-ray emission would be generated by massive star winds and by the remains of supernova explosions as massive stars evolve.

The mass of the entire gas cloud is uncertain because it cannot be determined from the two-dimensional image whether the hot gas is concentrated in a thin pancake or distributed over a large, spherical region. If the gas is a pancake, the mass is equivalent to forty thousand Suns. If it is spread out uniformly, the mass could be much larger, about three million times as massive as the Sun. This range agrees with values for dwarf galaxies in the Local Group containing the Milky Way.

The hot gas should continue to glow in X-rays for tens to hundreds of millions of years, depending on the geometry of the collision. The collision itself should last for about 50 million years. Therefore, searching for large regions of hot gas in galaxies might be a way to estimate the frequency of collisions with dwarf galaxies and to understand how important such events are to galaxy growth.

An alternative explanation of the X-ray emission is that the hot gas cloud could have been produced by supernovas and hot winds from large numbers of massive stars, all located on one side of the galaxy. The lack of evidence of expected radio, infrared, or optical features argues against this possibility.


Story Source:

The above story is based on materials provided by Chandra X-ray Observatory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Gordon P. Garmire. X-ray discovery of a dwarf-galaxy galaxy collision. The Astrophysical Journal, June 10th, 2013 [link]

Cite This Page:

Chandra X-ray Observatory. "Dwarf galaxy caught ramming into a large spiral." ScienceDaily. ScienceDaily, 14 August 2013. <www.sciencedaily.com/releases/2013/08/130814144708.htm>.
Chandra X-ray Observatory. (2013, August 14). Dwarf galaxy caught ramming into a large spiral. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/2013/08/130814144708.htm
Chandra X-ray Observatory. "Dwarf galaxy caught ramming into a large spiral." ScienceDaily. www.sciencedaily.com/releases/2013/08/130814144708.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Space & Time News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Video Shows Stars If They Were as Close to Earth as Sun

Video Shows Stars If They Were as Close to Earth as Sun

Buzz60 (Jan. 30, 2015) Russia&apos;s space agency created a video that shows what our sky would look like with different star if they were as close as our sun. Patrick Jones (@Patrick_E_Jones) walks us through the cool video. Video provided by Buzz60
Powered by NewsLook.com
Dog-Loving Astronaut Wins Best Photo of 2015

Dog-Loving Astronaut Wins Best Photo of 2015

Buzz60 (Jan. 30, 2015) Retired astronaut and television host, Leland Melvin, snuck his dogs into the NASA studio so they could be in his official photo. As Mara Montalbano (@maramontalbano) shows us, the secret is out. Video provided by Buzz60
Powered by NewsLook.com
NASA Holds Memorial to Remember Astronauts

NASA Holds Memorial to Remember Astronauts

AP (Jan. 29, 2015) NASA is remembering 17 astronauts who were killed in the line of duty and dozens more who have died since the agency&apos;s beginning. A remembrance ceremony was held Thursday at NASA&apos;s Marshall Space Flight Center in Alabama. (Jan. 29) Video provided by AP
Powered by NewsLook.com
Asteroid's Moon Spotted During Earth Flyby

Asteroid's Moon Spotted During Earth Flyby

Rumble (Jan. 27, 2015) Scientists working with NASA&apos;s Deep Space Network antenna at Goldstone, California discovered an unexpected moon while observing asteroid 2004 BL86 during its recent flyby past Earth. Credit to &apos;NASA JPL&apos;. Video provided by Rumble
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins