Featured Research

from universities, journals, and other organizations

Polaroid Sunglasses Let Astronomers Take A Closer Look At Black Holes

Date:
November 18, 2004
Source:
Particle Physics & Astronomy Research Council
Summary:
An international team led by an Edinburgh astronomer have discovered that by studying polarised light from black holes they can focus much more closely on what exactly is going on around them.

At the center of an active galaxy lies a monster: a supermassive black hole. As matter falls toward the hole, it forms a rotating, flattened disk called an accretion disk. Through processes still unknown, some black holes can form jets of matter and energy that stream outward. Active galactic nuclei, like the one depicted here in an artist’s illustration, are sites of gamma ray formation. GLAST will observe thousands of such sources.
Credit: Aurore Simonnet, Sonoma State University

An international team led by an Edinburgh astronomer have discovered that by studying polarised light from black holes they can focus much more closely on what exactly is going on around them. The work is published this week in the monthly notices of the Royal Astronomical Society on November 11th.

Studying black holes at the centre of galaxies is difficult. A huge amount of material is falling on to the centre in an active black hole system, and this falling material is thought to power the black hole, but scientists still don't understand this powering mechanism. One critical reason is that these black holes are just too far away for astronomers to isolate the light from them - or more accurately, the light from the compact region where the black holes are actually producing their energy.

However, Kishimoto at the University of Edinburgh and the international team of Antonucci at UC Santa Barbara, Boisson at Paris Observatory, and Blaes also at UC Santa Barbara, have used the Keck I telescope in Hawaii and European Southern Observatory's Very Large Telescope in Chile, to do this isolation of the light. They have looked at a small part of the light emitted from black holes - light that has been scattered as it passes through the clouds very nearby. This scattered light can cleverly be picked up by looking through a polaroid filter just like the lens of polaroid sunglasses, which essentially blocks the unwanted light from elsewhere in the galaxy. The scattered light is polarised so the light waves all line up in the same direction and can pass through the Polaroid filter, but light from the surrounding area which is not polarised is excluded by the filter.

Dr Kishimoto, who leads the team, explained the importance of the new method: "For the first time we can use visible light to focus on the part of a galaxy that is very close to the black hole. We are interested in an area only about one light-day across. Until now, without using Polaroid filters, we couldn't separate the visible light from the black hole from the light coming from a much larger region about 100 light-days across." To put this in context, the galaxies surrounding the black holes are about 30,000 light years across.

As a result of this closer look the team have found a new signal in the observed light that can provide information about the material around a black hole. The signal, called a 'Balmer edge' feature, reveals properties of the material and will allow the team to carry out more detailed modelling of the temperature and density of the region near black holes than has been possible before now. This feature is commonly used to diagnose the nature of the surface of the Sun and other stars, but has never before been seen in visible light from black holes.

The next step is for Kishimoto and his team to take a look at more black holes using this technique to see if the black holes at the centre of different types of galaxy all look the same. They can then try to understand the mechanism that powers a black hole. Kishimoto and the team are now observing many other black holes using other large telescopes.

###

1. One light-day is the distance light travels in one day i.e. 1/365 of a light-year.


Story Source:

The above story is based on materials provided by Particle Physics & Astronomy Research Council. Note: Materials may be edited for content and length.


Cite This Page:

Particle Physics & Astronomy Research Council. "Polaroid Sunglasses Let Astronomers Take A Closer Look At Black Holes." ScienceDaily. ScienceDaily, 18 November 2004. <www.sciencedaily.com/releases/2004/11/041116235926.htm>.
Particle Physics & Astronomy Research Council. (2004, November 18). Polaroid Sunglasses Let Astronomers Take A Closer Look At Black Holes. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2004/11/041116235926.htm
Particle Physics & Astronomy Research Council. "Polaroid Sunglasses Let Astronomers Take A Closer Look At Black Holes." ScienceDaily. www.sciencedaily.com/releases/2004/11/041116235926.htm (accessed September 17, 2014).

Share This



More Space & Time News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
NASA Picks Boeing and SpaceX to Ferry Astronauts

NASA Picks Boeing and SpaceX to Ferry Astronauts

AP (Sep. 16, 2014) — NASA is a giant step closer to launching Americans again from U.S. soil. It has announced it has picked Boeing and SpaceX to transport astronauts to the International Space Station in the next few years. (Sept. 16) Video provided by AP
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