M82 s Middle Mass Black Hole
Explanation:
Black
holes are probably the most
bizarre
creatures in
the modern astronomical zoo.
And after years of pondering
black
holes as either stellar mass objects seen in
binary star systems or enormous
supermassive black holes at the
centers of galaxies,
astronomers now have strong evidence for another exotic species --
middle mass black holes.
The leading candidate for the ultradense middle ground is
indicated in this false-color detail of a sharp x-ray picture
from the space-based Chandra Observatory.
A close-up of x-ray sources near the center of
starburst galaxy M82,
the cropped
Chandra
image spans about 4,000 light-years.
M82 itself is around 11 million light-years distant.
The arrowed source has recently been convincingly demonstrated to
exhibit
x-ray characteristics of an object whose
gravitational field holds more than 500 times the mass of the sun
within a volume the size of the moon!
Astronomers
also
note that unlike the supermassive variety
which are thought to lie at the centers of galaxies, this
middle mass black hole is about 600 light-years from the
center of M82.
Theories for the formation of a middle mass black hole
include the collapse of a "hyperstar"
formed by
the coalescence of many normal stars, or the
direct
merger of stellar mass black holes.
Tomorrow's picture: West Texas
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
