Hubble Space Telescope images of M84
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The Hubble Space Telescope was employed to investigate the central core of
the bright and large Virgo Cluster lenticular galaxy M84.
At left, an image is presented showing the inner nucleus of M84, exhibiting
conspicuous dark lanes; this image has been taken with the Wide Field
Planetary Camera 2 (WFPC2). The long blue frame marks the position where
a slit was layed over the very center of the galaxy (the bright dot), for
investigation with the Space Telescope Imaging Spectrograph (STIS), one of
the instruments newly installed at HST’s second servicing mission (STS-82,
Space Shuttle Discovery) in February 1997.
The STIS exposure on the right shows this slit as imaged by the spectrograph.
Shorter wavelengths are on the left, longer wavelengths to the right in this
image. Therefore, blueshifted light, emitted from gas approaching us, is
shown left of the mean bar, redshifted light from receding gas masses on the
right. STIS used the light of hydrogene, as well as nitrogene and sulfur ions
to obtain the data represented here. From the red and blue shift, the orbital
velocity of the gas around the central object can be calculated. From this
velocity, the mass of the central object follows. In case of the central
object of M84, 300 million solar masses are concentrated within a distance
of 26 light years from the galaxy’s center. It is widely believed that this
massive central object is a candidate
for a supermassive black hole.
The nucleus of M84 has previously been found to be an active emitter of
radio radiation.
(From: STScI-PRC97-12)
Last Modification: 21 Jun 1998 22:10 MET