Featured Research

from universities, journals, and other organizations

First Detection Of Magnetic Field In Distant Galaxy Surprises Astronomers

Date:
October 2, 2008
Source:
University of California - San Diego
Summary:
Using a powerful radio telescope to peer into the early universe, a team of California astronomers has obtained the first direct measurement of a nascent galaxy's magnetic field as it appeared 6.5 billion years ago.

The astronomers used the world's largest fully steerable radio telescope, which stands 485 feet tall -- taller than the Statue of Liberty.
Credit: NRAO/AUI

Using a powerful radio telescope to peer into the early universe, a team of California astronomers has obtained the first direct measurement of a nascent galaxy's magnetic field as it appeared 6.5 billion years ago.

Astronomers believe the magnetic fields within our own Milky Way and other nearby galaxies—which control the rate of star formation and the dynamics of interstellar gas--arose from a slow "dynamo effect." In this process, slowly rotating galaxies are thought to have generated magnetic fields that grew very gradually as they evolved over 5 billion to 10 billion years to their current levels.

But in the October 2 issue of Nature, the astronomers report that the magnetic field they measured in this distant "protogalaxy" is at least 10 times greater than the average value in the Milky Way.

"This was a complete surprise," said Arthur Wolfe, a professor of physics at UC San Diego's Center for Astrophysics and Space Sciences who headed the team. "The magnetic field we measured is at least an order of magnitude larger than the average value of the magnetic field detected in our own galaxy."

The astronomers from the University of California campuses at Berkeley, San Diego and Santa Cruz used the world's largest fully steerable radio telescope for their measurements—the Robert C. Byrd Green Bank Telescope in Green Bank, West Virginia operated by the National Science Foundation's National Radio Astronomy Observatory. The young protogalaxy they probed, DLA-3C286, is located in a region of the northern sky that is directly overhead during the spring.

Until recently, astronomers knew very little about magnetic fields outside our own galaxy, having directly measured the magnetic field in only one nearby galaxy. "And that field wasn't as strong as the field we saw," said Wolfe.

But a team of Swiss and American astronomers reported in the July 17 issue of Nature that an indirect measurement of the magnetic fields of 20 distant galaxies, using the bright light from quasars, suggests that the magnetic fields of young galaxies were as strong when the universe was only a third of its current age as they are in the mature galaxies today.

Wolfe said those indirect measurements and his team's latest direct measurement of a distant galaxy's magnetic field "do not necessarily cast doubt on the leading theory of magnetic field generation, the mean-field-dynamo model, which predicts that the magnetic field strengths should be much weaker in galaxies in the cosmological past."

"Our results present a challenge to the dynamo model, but they do not rule it out," he added. "Rather the strong field that we detect is in gas with little if no star formation, and an interesting implication is that the presence of the magnetic fields is an important reason why star formation is very weak in these types of protogalaxies."

Wolfe said his team has two other plausible explanations for what they observed. "We speculate that either we are seeing a field toward the central regions of a massive galaxy, since magnetic fields are known to be larger towards the centers of nearby galaxies. It is also possible that the field we detect has been amplified by a shock wave generated by the collision between two galaxies."

"In either case," he added, "our detection indicates that magnetic fields may be important factors in the evolution of galaxies, and in particular may be responsible for the low star formation rates detected throughout the gaseous progenitors of young galaxies in the early universe."

"The challenge now," said J. Xavier Prochaska, another member of the team who is a professor of astronomy at UC Santa Cruz, "is to perform observations like these on galaxies throughout the universe."

Other researchers involved in the discovery were Regina Jorgenson, a UCSD graduate student in physics; Carl Heiles, a professor of astronomy at UC Berkeley; and Timothy Robishaw, a graduate student at Berkeley. The study was funded by a grant from the National Science Foundation.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Cite This Page:

University of California - San Diego. "First Detection Of Magnetic Field In Distant Galaxy Surprises Astronomers." ScienceDaily. ScienceDaily, 2 October 2008. <www.sciencedaily.com/releases/2008/10/081001145016.htm>.
University of California - San Diego. (2008, October 2). First Detection Of Magnetic Field In Distant Galaxy Surprises Astronomers. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2008/10/081001145016.htm
University of California - San Diego. "First Detection Of Magnetic Field In Distant Galaxy Surprises Astronomers." ScienceDaily. www.sciencedaily.com/releases/2008/10/081001145016.htm (accessed September 1, 2014).

Share This




More Space & Time News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: NASA Captures Solar Flare

Raw: NASA Captures Solar Flare

AP (Sep. 1, 2014) NASA reported the sun emitted a mid-level solar flare, on August 24th. NASA's Solar Dynamics Observatory captured the images of the flare, which erupted on the left side of the sun. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Space Shuttle Discovery's Legacy, 30 Years Later

Space Shuttle Discovery's Legacy, 30 Years Later

Newsy (Aug. 30, 2014) The space shuttle Discovery launched for the very first time 30 years ago. Here's a look back at its legacy. Video provided by Newsy
Powered by NewsLook.com
Experiment Tests Whether Universe Is Actually A Hologram

Experiment Tests Whether Universe Is Actually A Hologram

Newsy (Aug. 27, 2014) Researchers at Fermilab are using a device called "The Holometer" to test whether our universe is actually a 2-D hologram that just seems 3-D. Video provided by Newsy
Powered by NewsLook.com
SpaceX’s Falcon 9 Rocket Explodes After Liftoff

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

Newsy (Aug. 23, 2014) The private spaceflight company says it is preparing a thorough investigation into Friday's mishap. Video provided by Newsy
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:
from the past week

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