Medical and Hospital News  
SPACE SCOPES
Hubble spots pair of wild galaxies joining cosmic civilization
by Brooks Hays
Baltimore (UPI) Aug 11, 2016


Scientists discover how disk galaxies form spiral arms
Fayetteville, Ark. (UPI) Aug 11, 2016 - The Milky Way is one of many disk galaxies with spiral arms, elongated and curved collections of gas and stars that snake outward from a dense galactic center.

New research by a pair of astrophysicists from the University of Arkansas offers support for a long-debated theory for how spiral arms form.

"Spiral galaxies are fascinating structures in astronomy, and the exact mechanism of the formation of spiral arms is still a mystery in astrophysics," scientist Hamed Pour-Imani said in a news release.

The evidence, detailed this week in the Astrophysical Journal Letters, lends strong support to the density wave theory of spiral galaxies.

The density wave theory posits that spiral arms are not material entities, but shifting areas of congestion. They're like traffic jams, with stars moving in and out of rush-hour traffic as they orbit the galactic center.

First proposed in the 1960s, the theory suggests the pitch angles of each spiral arm should shift with the wavelength of the galaxy's image.

Previous analysis failed to identify a correlation between pitch angle and wavelength, but in studying imagery from the NASA Spitzer Space Telescope at two infrared wavelengths, Pour-Imani and research partner Daniel Kennefick identified pitch angles in accordance with density wave theory.

After billions of years wandering in the proverbial wilderness, two galaxies, Pisces A and B, are returning to cosmic civilization.

Recently, the Hubble Space Telescope caught a glimpse of the two galaxies, having made their way into a much denser collection of galaxies -- a hub of cosmic activity astronomers are calling the "big city."

The wilderness the two galaxies wandered in from is called the Local Void. The lonely region spans some 150 million light-years.

Their return to civilization -- which actually began about 100 million years ago -- triggered a burst of creativity. A plethora of young blue stars suggests the two galaxies are birthing new stars at an accelerated clip. Researchers suspect the uptick in star formation was fueled by big city's denser supply of intergalactic gas.

"These Hubble images may be snapshots of what present-day dwarf galaxies may have been like at earlier epochs," lead researcher Erik Tollerud, an astronomer at the Space Telescope Science Institute in Baltimore, said in a news release. "Studying these and other similar galaxies can provide further clues to dwarf galaxy formation and evolution."

Though it is difficult to predict, researchers say the two galaxies' star formation could soon slow. If the dwarf galaxies get pulled into orbit around a larger galaxy, their gas supply is likely to be cut off.

"The galaxies could even probably stop forming stars altogether, because they will stop getting new gas to make stars," Tollerud said. "So they will use up their existing gas. But it's hard to tell right now exactly when that would happen, so it's a reasonable guess that the star formation will ramp up at least for a while."

The story of the two loner galaxies was detailed in a new paper published in the Astrophysical Journal.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Space Telescope News and Technology at Skynightly.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
SPACE SCOPES
Space... the final frontier
Munich, Germany (SPX) Jul 26, 2016
Fifty years ago Captain Kirk and the crew of the starship Enterprise began their journey into space - the final frontier. Now, as the newest Star Trek film hits cinemas, the NASA/ESA Hubble space telescope is also exploring new frontiers, observing distant galaxies in the galaxy cluster Abell S1063 as part of the Frontier Fields programme. Space... the final frontier. These are the stories ... read more


SPACE SCOPES
Syrian refugees invent app for Germany's bureaucracy maze

Shattered glass, broken promises a year after Tianjin blasts

Use of pulsed electric fields may reduce scar formation after burns, other injuries

Lost in translation: Chinese tourist taken for refugee in Germany

SPACE SCOPES
Existing navigation data can help pilots avoid turbulence

Russia to Develop Unmanned Harvester Running on Glonass Navigation by 2018

Raytheon gets $52 million Miniature Airborne GPS task order

India to Provide Cost Incentives to Use Homemade Version of GPS

SPACE SCOPES
How did primate brains get so big

Total number of neurons - not enlarged prefrontal region - hallmark of human brain

Archaeologists find Britain's last hunter-gatherers on small island

Scientists decode sentence signatures among brain activity patterns

SPACE SCOPES
Greenland sharks live for hundreds of years

Galapagos faces first-ever bird extinction

Tracing the evolution of bird reproduction

Managing climate change refugia to protect wildlife

SPACE SCOPES
Miami residents fret over pesticide used to fight Zika

Scientists warn anthrax just one threat as Russian permafrost melts

Warmer climate could lower dengue risk

Study pushes back the origin of HIV-related retroviruses to 60 million years ago

SPACE SCOPES
Hong Kong pro-democracy leaders escape jail on protest charges

Top China official slams foreign influence on Tibetan Buddhism

Hong Kong pro-democracy leaders escape jail on protest charges

Chinese ID mix-up leaves dead man walking

SPACE SCOPES
SPACE SCOPES
China retail sales growth slows in July, misses expectations

IMF warns on China's mid-term economic stability

China's trade performance disappoints in July

Japan approves huge stimulus for sluggish economy









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.