Go Back   nV News Forums > General Forums > Archived News Items

Newegg Daily Deals

Reply
 
Thread Tools
Old 07-11-12, 02:20 PM   #1
News
Registered User
 
Join Date: Jun 2009
Posts: 47,015
Post Black hole shines a light on dark galaxies

Ultraviolet light from a quasar (in the red circle) causes hydrogen gas in dark galaxies (blue circles) to fluoresce.
ESO/Digitized Sky Survey 2/S. Cantalupo (UCSC)


According to our best models, the early Universe was filled with clouds of gas that were the source of its current galaxies. However, not all of these protogalactic nebulas were massive enough to compress their gas sufficiently to make stars. This means a number of "dark galaxies" should exist: galaxy-sized clouds of gas with few or no stars. This lack of stars makes dark galaxies extremely hard to find, but a group of astronomers using the Very Large Telescope (VLT) in Chile have identified 12 candidates from the early days of the Universe.These results have the potential to fill in some of the observational gaps in our understanding of early galaxy formation and evolution.

The trick for spotting these dark galaxies is described in Monthly Notices of the Royal Astronomical Society by Sebastiano Cantalupo, Simon J. Lilly, and Martin G. Haehnelt, who located a quasar, a supermassive black hole pumping out large quantities of ultraviolet (UV) light. Just as UV emission from mercury drives fluorescent lights, the UV light from the quasar caused gas in the dark galaxies to fluoresce, making them faintly visible.

The researchers estimated the candidate clouds' masses would be comparable to dwarf galaxies today, much smaller than star-forming galaxies at the same distance from Earth. They also identified filaments of gas, which might be the signature of material falling in to the dark galaxies.

Read 7 remaining paragraphs | Comments






More...
News is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wich will make a Green UV fan/acrylic pann glow more a green light or black light ??? muelo1000 General Hardware 0 07-07-12 09:12 PM
Dark matter is the thread connecting galaxy clusters News Archived News Items 0 07-05-12 10:50 AM
$99.99 - ASUS VW225T-B Black 22" 5ms Widescreen LCD Monitor, B Grade, Light Scratches News 22-Inch 0 06-11-12 01:30 PM
$101.99 - ASUS VW224T-B Black 22" 5ms Widescreen LCD Monitor, B Grade, Light Scratch News 22-Inch 0 06-10-12 01:24 PM
$92.99 - ASUS VH202T-PB Glossy Black 20" 5ms Widescreen LCD Monitor, B Grade, Light News 20-Inch 0 06-10-12 01:17 PM

All times are GMT -5. The time now is 02:02 AM.


Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 1998 - 2014, nV News.