Featured Research

from universities, journals, and other organizations

Astronomers ask 'where are all the dwarf galaxies?'

Date:
February 1, 2013
Source:
Leibniz-Institut für Astrophysik Potsdam (AIP)
Summary:
Astronomers have identified “Cosmic Web Stripping” as a new way of explaining the famous missing dwarf problem: the lack of observed dwarf galaxies compared with that predicted by the theory of Cold Dark Matter and Dark Energy.

Cosmic Web Stripping.
Credit: Alejandro Benitez Llambay

Astronomers of the international CLUES collaboration have identified "Cosmic Web Stripping" as a new way of explaining the famous missing dwarf problem: the lack of observed dwarf galaxies compared with that predicted by the theory of Cold Dark Matter and Dark Energy.

High-precision observations over the last two decades have indicated that our Universe consists of about 75% Dark Energy, 20% Dark Matter and 5% ordinary matter. Galaxies and matter in the universe clump in an intricate network of filaments and voids, known as the Cosmic Web. Computer experiments on massive supercomputers have shown that in such a Universe a huge number of small "dwarf" galaxies weighing just one thousandth of the Milky Way should have formed in our cosmic neighbourhood. Yet only a handful of these galaxies are observed orbiting around the Milky Way. The observed scarcity of dwarf galaxies is a major challenge to our understanding of galaxy formation.

An international team of researchers has studied this issue within the Constrained Local UniversE Simulations project (CLUES). The CLUES simulations use the observed positions and peculiar velocities of galaxies within Tens of Millions of light years of the Milky Way to accurately simulate the local environment of the Milky Way. "The main goal of this project is to simulate the evolution of the Local Group -- the Andromeda and Milky Way galaxies and their low-mass neighbours -- within their observed large scale environment," said Stefan Gottlöber of the Leibniz Institute for Astrophysics Potsdam.

Analysing the CLUES simulations, the astronomers have now found that some of the far-out dwarf galaxies in the Local Group move with such high velocities with respect to the Cosmic Web that most of their gas can be stripped and effectively removed. They call this mechanism "Cosmic Web Stripping," since it is the pancake and filamentary structure of the cosmos that is responsible for depleting the dwarfs' gas supply.

"These dwarfs move so fast that even the weakest membranes of the Cosmic Web can rip off their gas," explained Alejandro Benítez LLambay, PhD student at the Instituto de Astronomía Teórica y Experimental of the Universidad Nacional de Córdoba in Argentina, and first author of the publication of this study. Without a large gas reservoir out of which to form stars, these dwarf galaxies should be so small and dim that they would be hardly be visible today. The missing dwarfs may simply be too faint to see.


Story Source:

The above story is based on materials provided by Leibniz-Institut für Astrophysik Potsdam (AIP). Note: Materials may be edited for content and length.


Journal Reference:

  1. Alejandro Benítez-Llambay, Julio F. Navarro, Mario G. Abadi, Stefan Gottlöber, Gustavo Yepes, Yehuda Hoffman, Matthias Steinmetz. Dwarf Galaxies and the Cosmic Web. The Astrophysical Journal, 2013; 763 (2): L41 DOI: 10.1088/2041-8205/763/2/L41

Cite This Page:

Leibniz-Institut für Astrophysik Potsdam (AIP). "Astronomers ask 'where are all the dwarf galaxies?'." ScienceDaily. ScienceDaily, 1 February 2013. <www.sciencedaily.com/releases/2013/02/130201090359.htm>.
Leibniz-Institut für Astrophysik Potsdam (AIP). (2013, February 1). Astronomers ask 'where are all the dwarf galaxies?'. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2013/02/130201090359.htm
Leibniz-Institut für Astrophysik Potsdam (AIP). "Astronomers ask 'where are all the dwarf galaxies?'." ScienceDaily. www.sciencedaily.com/releases/2013/02/130201090359.htm (accessed October 22, 2014).

Share This



More Space & Time News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Russian Cosmonauts Kick Off Final Spacewalk of 2014

Russian Cosmonauts Kick Off Final Spacewalk of 2014

Reuters - US Online Video (Oct. 22, 2014) — Russian cosmonauts Maxim Suraev and Alexander Samokutyaev step outside the International Space Station to perform work on the exterior of the station's Russian module. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) — A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) — Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) — Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
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