Featured Research

from universities, journals, and other organizations

Seeing Double: Spitzer Captures Our Galaxy's Twin

Date:
July 1, 2004
Source:
NASA/Jet Propulsion Laboratory
Summary:
What would our Milky Way galaxy look like if we could travel outside it and snap a picture? It might look a lot like a new image by NASA's Spitzer Space Telescope of a spiral galaxy called NGC 7331 - a virtual twin of our Milky Way.

NASA's Spitzer Space Telescope has captured this infrared image of a nearby spiral galaxy that resembles our own Milky Way. The targeted galaxy, known as NGC 7331 and sometimes referred to as our galaxy's twin, is found in the constellation Pegasus at a distance of 50 million light-years.
Credit: Image NASA/JPL-Caltech/STScI

What would our Milky Way galaxy look like if we could traveloutside it and snap a picture? It might look a lot like anew image by NASA's Spitzer Space Telescope of a spiralgalaxy called NGC 7331 - a virtual twin of our Milky Way.

Related Articles


The picture, which can be viewed athttp://photojournal.jpl.nasa.gov/catalog/PIA06322 , shows our twin as neverbefore. Its swirling arms spin outward from a central bulgeof light, which is outlined by a ring of actively formingstars.

"Being inside our galaxy makes it difficult to see what'sgoing on in the center," said Dr. J.D. Smith, a member ofthe team that observed NGC 7331, and an astronomer at theUniversity of Arizona, Tucson. "By looking at a very similargalaxy, we gain a bird's eye-view of what the entire MilkyWay might look like."

Such an outside perspective will teach astronomers how ourown galaxy, as well as others like it, might have formed andevolved.

The latest observations are the first in a large-scaleeffort to observe 75 nearby galaxies with Spitzer's highlysensitive infrared eyes. Called Spitzer Infrared NearbyGalaxies Survey, the program will combine Spitzer data withthat from other ground- and space-based telescopes operatingat wavelengths ranging from ultraviolet to radio to create acomprehensive map of the selected galaxies.

The program's first target, NGC 7331, was chosen in part forits striking similarities to the Milky Way. While these so-called twin galaxies do not share the same parents, theyhave many features in common, including number of stars,mass, spiral arm pattern and star-formation rate of a fewstars per year. Whether the Milky Way has an inner star-forming ring like that of NGC 7331 is not known. NGC 7331 islocated about 50 million light-years away in theconstellation Pegasus.

The new Spitzer image demonstrates the power of thetelescope's infrared eyes to dissect galaxies into theirvarious parts. Taken by the telescope's infrared arraycamera, the false-colored picture readily distinguishes NGC7331's arms (brownish red), central bulge (blue) and star-forming ring (yellow). The composition of materials makingup these regions was also revealed by the Spitzerobservations: the central bulge consists primarily of olderstars; the ring possesses a large amount of gas and dustyorganic molecules called polycyclic aromatic hydrocarbons,which typically glow when illuminated by newborn stars; andthe arms contain these same dust grains to a lesser degree.Polycyclic aromatic hydrocarbons are also found on Earth, onburnt toast and in car exhaust among other places.

Data from Spitzer's infrared spectrograph instrument werealso used to show that the center of NGC 7331 harbors eitheran unusually high concentration of massive stars, or amoderately active black hole about the same size as the onelurking at the core of our galaxy.

These findings will appear in two papers in the Septemberissue of a special supplement to the Astrophysical Journal.Dr. Michael W. Regan of the Space Telescope Institute,Baltimore, Md., is lead author of a paper detailingobservations from the infrared array camera, and Smith islead author of a paper on the infrared spectrograph results.The Spitzer Infrared Nearby Galaxies Survey project isconducted by a team of about 25 scientists from 12institutions, and is led by principal investigator Dr.Robert C. Kennicutt of the University of Arizona, Tucson.

Launched August 25, 2003, the Spitzer Space Telescope is thefourth of NASA's Great Observatories, a program that alsoincludes the Hubble Space Telescope, Chandra X-rayObservatory and Compton Gamma Ray Observatory.

JPL manages the Spitzer Space Telescope mission for NASA'sOffice of Space Science, Washington, D.C. Science operationsare conducted at the Spitzer Science Center at theCalifornia Institute of Technology in Pasadena. JPL is adivision of Caltech. Spitzer's infrared spectrograph wasbuilt by Cornell University, Ithaca, N.Y., and BallAerospace Corporation, Boulder, Colo. The instrument'sdevelopment was led by Dr. Jim Houck of Cornell. Spitzer'sinfrared array camera was built by NASA Goddard Space FlightCenter, Greenbelt, Md. The camera's development was led byDr. Giovanni Fazio of Smithsonian Astrophysical Observatory,Cambridge, Mass.

Additional information about the Spitzer Space Telescope isavailable at http://www.spitzer.caltech.edu .


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Jet Propulsion Laboratory. "Seeing Double: Spitzer Captures Our Galaxy's Twin." ScienceDaily. ScienceDaily, 1 July 2004. <www.sciencedaily.com/releases/2004/06/040629015009.htm>.
NASA/Jet Propulsion Laboratory. (2004, July 1). Seeing Double: Spitzer Captures Our Galaxy's Twin. ScienceDaily. Retrieved January 30, 2015 from www.sciencedaily.com/releases/2004/06/040629015009.htm
NASA/Jet Propulsion Laboratory. "Seeing Double: Spitzer Captures Our Galaxy's Twin." ScienceDaily. www.sciencedaily.com/releases/2004/06/040629015009.htm (accessed January 30, 2015).

Share This


More From ScienceDaily



More Space & Time News

Friday, January 30, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Mars Rover Opportunity Celebrates 11-Year Anniversary

Mars Rover Opportunity Celebrates 11-Year Anniversary

Rumble (Jan. 26, 2015) Eleven years ago NASA&apos;s Opportunity rover touched down on Mars for what was only supposed to be a 90-day mission. Since then it has traveled 25.9 miles (41.7 kilometers), further than any other off-Earth surface vehicle has ever driven. Credit to &apos;NASA&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