Spitzer photo atlas of galaxy 'train wrecks'

May 25, 2011
The Spitzer photo atlas of galactic 'train wrecks'
This three-color image of NGC 3448 (left) and its companion UGC 6016 (right) shows far-UV emission from young stars observed by GALEX in blue, heated dust mid-infrared emission observed by Spitzer in red, and stellar near-infrared emission observed by Spitzer in green. This pair of galaxies is only separated by 75,000 light-years, and its UV emission shows a bridge of material between the two galaxies. Credit: NASA / JPL-Caltech / L. Lanz (Harvard-Smithsonian CfA)

(PhysOrg.com) -- Five billion years from now, our Milky Way Galaxy will collide with the Andromeda Galaxy. This will mark a moment of both destruction and creation. The galaxies will lose their separate identities as they merge into one. At the same time, cosmic clouds of gas and dust will smash together, triggering the birth of new stars.

To understand our past and imagine our future, we must understand what happens when galaxies collide. But since galaxy collisions take place over millions to billions of years, we can’t watch a single collision from start to finish. Instead, we must study a variety of colliding galaxies at different stages. By combining recent data from two space
telescopes, astronomers are gaining fresh insights into the collision process.

“We’ve assembled an atlas of galactic ‘train wrecks’ from start to finish. This atlas is the first step in reading the story of how galaxies form, grow, and evolve,” said lead author Lauranne Lanz of the Harvard-Smithsonian Center for Astrophysics (CfA).

Lanz presented her findings today in a press conference at the 218th meeting of the American Astronomical Society.

The Spitzer photo atlas of galactic 'train wrecks'
This three-color image of NGC 935 and its companion IC 1801 shows far-UV emission from young stars observed by GALEX in blue, heated dust mid-infrared emission observed by Spitzer in red, and stellar near-infrared emission observed by Spitzer in green. This pair of spiral galaxies is beginning to crash into each other. Credit: NASA / JPL-Caltech / L. Lanz (Harvard-Smithsonian CfA)

The new images combine observations from NASA’s Spitzer Space Telescope, which observes infrared light, and Galaxy Evolution Explorer (GALEX) spacecraft, which observes ultraviolet light. By analyzing information from different parts of the light spectrum, scientists can learn much more than from a single wavelength alone, because they observe different components of a galaxy.

GALEX’s ultraviolet data captures the emission from hot young stars. Spitzer sees the infrared emission from warm dust heated by those stars, as well as from stellar surfaces. Therefore, GALEX’s ultraviolet data and Spitzer’s infrared data highlight areas where stars are forming most rapidly, and together permit a more complete census of the new stars.

In general, galaxy collisions spark star formation. However, some interacting show fewer than others. Lanz and her colleagues want to figure out what differences in physical processes cause these different outcomes. Their findings will also help guide computer simulations of galaxy collisions.

The Spitzer photo atlas of galactic 'train wrecks'
This three-color image of NGC 470 (top) and NGC 474 (bottom) shows far-UV emission from young stars observed by GALEX in blue, heated dust mid-infrared emission observed by Spitzer in red, and stellar near-infrared emission observed by Spitzer in green. These galaxies are likely to be on their first pass past each other and are therefore relatively undisturbed at a separation of 160,000 light-years. Credit: NASA / JPL-Caltech / L. Lanz (Harvard-Smithsonian CfA)

“We’re working with the theorists to give our understanding a reality check,” said Lanz. “Our understanding will really be tested in five billion years, when the Milky Way experiences its own collision.”

Lanz’s co-authors are Nicola Brassington (Univ. of Hertfordshire, UK); Andreas Zezas (Univ. of Crete, Greece); Howard Smith and Matt Ashby (CfA); Christopher Klein (UC Berkeley); and Patrik Jonsson, Lars Hernquist, and Giovanni Fazio (CfA).

Explore further: Spitzer Witnessed Galactic Collision

Related Stories

Spitzer Witnessed Galactic Collision

September 10, 2004

NASA's Spitzer Space Telescope has set its infrared sight on a major galactic collision and witnessed not death, but a teeming nest of life. The colliding galaxies, called the Antennae galaxies, are in the process of merging ...

Amazing Andromeda Galaxy

October 3, 2006

The many "personalities" of our great galactic neighbor, the Andromeda galaxy, are exposed in this new composite image from NASA's Galaxy Evolution Explorer and the Spitzer Space Telescope.

Galaxy Cores to Crash in a Few Million Years

March 16, 2009

(PhysOrg.com) -- A new image from NASA's Spitzer Space Telescope offers a rare view of an imminent collision between the cores of two merging galaxies, each powered by a black hole with millions of times the mass of the sun. ...

The outbursts of Fornax

October 1, 2010

(PhysOrg.com) -- The galaxy Fornax A, at a distance of about 74 million light-years, is one of the nearest and brightest galaxies with giant radio lobes. These huge radio lobes -- they span a million light-years -- are immense ...

Andromeda in a new light

January 5, 2011

Two ESA observatories have combined forces to show the Andromeda Galaxy in a new light. Herschel sees rings of star formation in this, the most detailed image of the Andromeda Galaxy ever taken at infrared wavelengths, and ...

Giant galaxies akin to snowflakes in space

February 21, 2011

(PhysOrg.com) -- Giant galaxies that contain billions of stars are born in much the same way as delicate snowflakes, new research from Swinburne University of Technology has shown.

Recommended for you

Distant planet's interior chemistry may differ from our own

September 1, 2015

As astronomers continue finding new rocky planets around distant stars, high-pressure physicists are considering what the interiors of those planets might be like and how their chemistry could differ from that found on Earth. ...

New Horizons team selects potential Kuiper Belt flyby target

August 29, 2015

NASA has selected the potential next destination for the New Horizons mission to visit after its historic July 14 flyby of the Pluto system. The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 that orbits ...

Image: Hubble sees a youthful cluster

August 31, 2015

Shown here in a new image taken with the Advanced Camera for Surveys (ACS) on board the NASA/ESA Hubble Space Telescope is the globular cluster NGC 1783. This is one of the biggest globular clusters in the Large Magellanic ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Mahal_Kita
1 / 5 (4) May 25, 2011
"Our past" and "our future".. This is wrong. It is the warped sense of self-importance of narcissistic personality disorder. Statistically "we" do not even exist in the Universe as we know it.
T2Nav
5 / 5 (2) May 25, 2011
And yet here I am.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.