Images by Date
Images by Category
Solar System
Stars
White Dwarfs
Supernovas
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Quasars
Galaxy Clusters
Cosmology/Deep Field
Miscellaneous
Images by Interest
Chandra for Kids
Multiwavelength
Sky Map
Constellations
3D Wall
Photo Blog
Top Rated Images
Image Handouts
Desktops
High Res Prints
Fits Files
Image Tutorials
Photo Album Tutorial
False Color
Cosmic Distance
Look-Back Time
Scale & Distance
Angular Measurement
Images & Processing
AVM/Metadata
Getting Hard Copies
Image Use Policy
Web Shortcuts
Chandra Blog
RSS Feed
Chandra Mobile
Chronicle
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
NGC 4649: A New Way To Weigh Giant Black Holes
NGC 4649


This is a composite image of data from NASA’s Chandra X-ray Observatory (shown in purple) and Hubble Space Telescope (blue) of the giant elliptical galaxy, NGC 4649, located about 51 million light years from Earth. Although NGC 4649 contains one of the biggest black holes in the local Universe, there are no overt signs of its presence because the black hole is in a dormant state. The lack of a bright central point in either the X-ray or optical images shows that the supermassive black hole does not appear to be rapidly pulling in material towards its event horizon, nor generating copious amounts of light as it grows. Also, the very smooth appearance of the Chandra image shows that the hot gas producing the X-rays has not been disturbed recently by outbursts from a growing black hole.

So, the presence and mass of the black hole in NGC 4649, and other galaxies like it, has to be studied more indirectly by tracking its effects on stars and gas surrounding it. By applying a clever technique for the first time, scientists used Chandra data to measure a mass for the black hole of about 3.4 billion times that of the Sun. The new technique takes advantage of the gravitational influence the black hole has on the hot gas near the center of the galaxy. As gas slowly settles towards the black hole, it gets compressed and heated. This causes a peak in the temperature of the gas right near the center of the galaxy. The more massive the black hole, the bigger the temperature peak detected by Chandra.

Reassuringly, the estimate of the black hole's mass using this X-ray technique is consistent with a more traditional technique using the motions of stars near the black hole. NGC 4649 is now one of only a handful of galaxies for which the mass of a supermassive black hole has been measured with two different methods.

Fast Facts for NGC 4649:
Credit  X-ray (NASA/CXC/Univ. of California Irvine/P.Humphrey et al.); Optical (NASA/STScI)
Release Date  July 16, 2008
Scale  Image is 26 arcsec across.
Category  Normal Galaxies & Starburst Galaxies
Coordinates (J2000)  RA | Dec
Constellation  Virgo
Observation Date  Three pointings between 04/20/2000 - 02/01/2007
Observation Time  22 hours and 30 minutes.
Obs. ID  785, 8182, 8507
Instrument  ACIS
Also Known As PGC 42831
References Humphrey P. et al (2008), ApJ, accepted
Color Code  X-ray (purple); Optical (blue)
Optical
X-ray
Distance Estimate  About 60 million light years
Visitor Comments (0)
Leave Your Comment

Name:

Email:

Comments:


 
 

Rules

Rate This Image

Rating: 2.0/5
(186 votes cast)
Download & Share

More Information
Press Room: NGC 4649
More Images
Chandra X-ray Image
of NGC 4649
Jpg, Tif
Illustration

More Images
More Releases
NGC 4649
NGC 4649
(04 Jun 02)

Related Images
Related Information
Related Podcast
Top Rated Images
G352.7-0.1

El Gordo

IGR J11014-6103




FaceBookTwitterYouTubeFlickr