Featured Research

from universities, journals, and other organizations

Best ultraviolet maps of the nearest galaxies

Date:
June 3, 2013
Source:
NASA/Goddard Space Flight Center
Summary:
Astronomers have used NASA's Swift satellite to create the most detailed ultraviolet light surveys ever of the Large and Small Magellanic Clouds, the two closest major galaxies.

The LMC as it appears in visible light. The galaxy's most prominent object is the sprawling Tarantula Nebula (middle left), the largest star factory in the LMC and the most active star-formation zone among the dozens of galaxies that make up the Local Group, which includes our own Milky Way and the Andromeda galaxy (M31). The LMC is about 14,000 light-years across.
Credit: Axel Mellinger, Central Michigan Univ

Astronomers at NASA and Pennsylvania State University have used NASA's Swift satellite to create the most detailed ultraviolet light surveys ever of the Large and Small Magellanic Clouds, the two closest major galaxies.

Related Articles


"We took thousands of images and assembled them into seamless portraits of the main body of each galaxy, resulting in the highest-resolution surveys of the Magellanic Clouds at ultraviolet wavelengths," said Stefan Immler, who proposed the program and led NASA's contribution from the agency's Goddard Space Flight Center in Greenbelt, Md.

Immler presented a 160-megapixel mosaic image of the Large Magellanic Cloud (LMC) and a 57-megapixel mosaic image of the Small Magellanic Cloud (SMC)at the 222nd American Astronomical Society meeting in Indianapolis on Monday.

The new images reveal about 1 million ultraviolet sources in the LMC and about 250,000 in the SMC. The images include light ranging from 1,600 to 3,300 angstroms, which is a range of UV wavelengths largely blocked by Earth's atmosphere.

"Prior to these images, there were relatively few UV observations of these galaxies, and none at high resolution across such wide areas, so this project fills in a major missing piece of the scientific puzzle," said Michael Siegel, lead scientist for Swift's Ultraviolet/Optical Telescope (UVOT) at the Swift Mission Operations Center at the university in State College, Pa.

The LMC and SMC lie about 163,000 light-years and 200,000 light-years away, respectively, and orbit each other as well as our own Milky Way galaxy. The LMC is about one-tenth the size of the Milky Way and contains only 1 percent of the Milky Way's mass. The SMC is half the size of the LMC and contains about two-thirds of its mass.

Despite their modest sizes, the galaxies loom large in the sky because they are so close to us. Both extend far beyond the UVOT's field of view, which meant thousands of images were needed in order to cover both galaxies in three ultraviolet colors centered at wavelengths of 1,928 angstroms, 2,246 angstroms, and 2,600 angstroms.

Viewing in the ultraviolet allows astronomers to suppress the light of normal stars like the sun, which are not very bright at such higher energies, and provides a clearer picture of the hottest stars and star-formation regions. No telescope other than UVOT can produce such high-resolution wide-field multicolor surveys in the ultraviolet. Swift's wide-field imaging capabilities provide a powerful complement to the deeper, but much narrower-field imaging power of NASA's Hubble Space Telescope.

To produce the 160-megapixel LMC mosaic, Swift's UVOT acquired 2,200 snapshots for a cumulative exposure of 5.4 days. The 57-megapixel SMC image comprises 656 individual images with a total exposure of 1.8 days.

Both images have an angular resolution of 2.5 arc seconds, which is a measure of their sharpness. Sources separated by this angle, which is equivalent to the size of a dime seen from 1mile away, are visible as distinct objects.

"With these mosaics, we can study how stars are born and evolve across each galaxy in a single view, something that's very difficult to accomplish for our own galaxy because of our location inside it," Immler said.

The Large and Small Magellanic Clouds are readily visible from the Southern Hemisphere as faint, glowing patches in the night sky. The galaxies are named after Ferdinand Magellan, the Portuguese explorer who in 1519 led an expedition to sail around the world. He and his crew were among the first Europeans to sight the objects.

Pennsylvania State University manages the Swift Mission Operations Center, which controls Swift's science and flight operations. Goddard manages Swift, which was launched in November 2004. The satellite is operated in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico and Orbital Sciences Corp. in Dulles, Va. International collaborators are in the United Kingdom and Italy, and the mission includes contributions from Germany and Japan.


Story Source:

The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Goddard Space Flight Center. "Best ultraviolet maps of the nearest galaxies." ScienceDaily. ScienceDaily, 3 June 2013. <www.sciencedaily.com/releases/2013/06/130603183206.htm>.
NASA/Goddard Space Flight Center. (2013, June 3). Best ultraviolet maps of the nearest galaxies. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2013/06/130603183206.htm
NASA/Goddard Space Flight Center. "Best ultraviolet maps of the nearest galaxies." ScienceDaily. www.sciencedaily.com/releases/2013/06/130603183206.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Space & Time News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Spokesman: 'NORAD Ready to Track Santa'

Spokesman: 'NORAD Ready to Track Santa'

AP (Dec. 19, 2014) Pentagon spokesman Rear Adm. John Kirby said that NORAD is ready to track Santa Claus as he delivers gifts next week. Speaking tongue-in-cheek, he said if Santa drops anything off his sleigh, "we've got destroyers out there to pick them up." (Dec. 19) Video provided by AP
Powered by NewsLook.com
NASA's Planet-Finding Kepler Mission Isn't Over After All

NASA's Planet-Finding Kepler Mission Isn't Over After All

Newsy (Dec. 18, 2014) More than a year after NASA declared the Kepler spacecraft broken beyond repair, scientists have figured out how to continue getting useful data. Video provided by Newsy
Powered by NewsLook.com
Rover Finds More Clues About Possible Life On Mars

Rover Finds More Clues About Possible Life On Mars

Newsy (Dec. 17, 2014) NASA's Curiosity rover detected methane on Mars and organic compounds on the surface, but it doesn't quite prove there was life ... yet. Video provided by Newsy
Powered by NewsLook.com
Evidence of Life on Mars? NASA Rover Finds Methane, Organic Chemicals

Evidence of Life on Mars? NASA Rover Finds Methane, Organic Chemicals

Reuters - US Online Video (Dec. 16, 2014) NASA's Mars Curiosity rover finds methane in the Martian atmosphere and organic chemicals in the planet's soil, the latest hint that Mars was once suitable for microbial life. Linda So reports. Video provided by Reuters
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