Featured Research

from universities, journals, and other organizations

Map of universe questioned: Dwarf galaxies don't fit standard model

Date:
June 11, 2014
Source:
Rochester Institute of Technology
Summary:
Dwarf galaxies that orbit the Milky Way and the Andromeda galaxies defy the accepted model of galaxy formation, and recent attempts to wedge them into the model are flawed, reports an international team of astrophysicists. A new study pokes holes in the current understanding of galaxy formation and questions the accepted model of the origin and evolution of the universe.

An optical image of the "Tadpole" galaxy, an interacting galaxy, taken by the Hubble Space Telescope. Material stripped from the galaxy during its collision with a smaller galaxy (seen in the upper left corner of the larger interaction partner) forms a long tidal tail. Young blue stars, star clusters and tidal dwarf galaxies are born in these tidal debris. These objects move in a common direction within a plane defined by the orientation and motion of their tidal tail. A similar galaxy interaction might have occurred in the Local Group in the past, which could explain the distribution of dwarf galaxies in co-rotating planes.
Credit: NASA, Holland Ford (JHU), the ACS Science Team and ESA

Dwarf galaxies that orbit the Milky Way and the Andromeda galaxies defy the accepted model of galaxy formation, and recent attempts to wedge them into the model are flawed, reports an international team of astrophysicists.

David Merritt, professor of astrophysics at Rochester Institute of Technology, co-authored "Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies," to be published in an upcoming issue of Monthly Notices of the Royal Astronomical Society.

The study pokes holes in the current understanding of galaxy formation and questions the accepted model of the origin and evolution of the universe. According to the standard paradigm, 23 percent of the mass of the universe is shaped by invisible particles known as dark matter.

"The model predicts that dwarf galaxies should form inside of small clumps of dark matter and that these clumps should be distributed randomly about their parent galaxy," Merritt said. "But what is observed is very different. The dwarf galaxies belonging to the Milky Way and Andromeda are seen to be orbiting in huge, thin disk-like structures."

The study, led by Marcel Pawlowski at Case Western Reserve University, critiques three recent papers by different international teams, all of which concluded that the satellite galaxies support the standard model. The critique by Merritt and his colleagues found "serious issues" with all three studies.

The team of 14 scientists from six different countries replicated the earlier analyses using the same data and cosmological simulations and came up with much lower probabilities -- roughly one tenth of a percent -- that such structures would be seen in the Milky Way and the Andromeda galaxy.

"The earlier papers found structures in the simulations that no one would say really looked very much like the observed planar structures," said Merritt.

In their paper, Merritt and his co-authors write that, "Either the selection of model satellites is different from that of the observed ones, or an incomplete set of observational constraints has been considered, or the observed satellite distribution is inconsistent with basic assumptions. Once these issues have been addressed, the conclusions are different: Features like the observed planar structures are very rare."

The standard cosmological model is the frame of reference for many generations of scientists, some of whom are beginning to question its ability to accurately reproduce what is observed in the nearby universe. Merritt counts himself among the small and growing group that is questioning the accepted paradigm.

"Our conclusion tends to favor an alternate, and much older, model: that the satellites were pulled out from another galaxy when it interacted with the Local Group galaxies in the distant past," he said. "This 'tidal' model can naturally explain why the observed satellites are orbiting in thin disks."

Scientific progress embraces challenges to upheld theories and models for a reason, Merritt notes.

"When you have a clear contradiction like this, you ought to focus on it," Merritt said. "This is how progress in science is made."


Story Source:

The above story is based on materials provided by Rochester Institute of Technology. The original article was written by Susan Gawlowicz. Note: Materials may be edited for content and length.


Journal Reference:

  1. Marcel S. Pawlowski, Benoit Famaey, Helmut Jerjen, David Merritt, Pavel Kroupa, Jörg Dabringhausen, Fabian Lüghausen, Duncan A. Forbes, Gerhard Hensler, François Hammer, Mathieu Puech, Sylvain Fouquet, Hector Flores, Yanbin Yang. Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies. Monthly Notices of the Royal Astronomical Society, 2014 [link]

Cite This Page:

Rochester Institute of Technology. "Map of universe questioned: Dwarf galaxies don't fit standard model." ScienceDaily. ScienceDaily, 11 June 2014. <www.sciencedaily.com/releases/2014/06/140611093627.htm>.
Rochester Institute of Technology. (2014, June 11). Map of universe questioned: Dwarf galaxies don't fit standard model. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2014/06/140611093627.htm
Rochester Institute of Technology. "Map of universe questioned: Dwarf galaxies don't fit standard model." ScienceDaily. www.sciencedaily.com/releases/2014/06/140611093627.htm (accessed September 20, 2014).

Share This



More Space & Time News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) — The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
Boeing, SpaceX to Send Astronauts to Space Station

Boeing, SpaceX to Send Astronauts to Space Station

AFP (Sep. 17, 2014) — NASA selected Boeing and SpaceX on Tuesday to build America's next spacecraft to carry astronauts to the International Space Station (ISS) by 2017, opening the way to a new chapter in human spaceflight. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) — Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama 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:
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