HST Images of Bipolar Nuclear Shells From the Active Galaxy NGC 4438
Click on the images to get a full view!

  [NGC 4438 Nucleus]

 Close-up of NGC 4438 Nucleus Showing Outflow Shells

False color image from Hubble Space Telescope of bubbles 
of hot gas blown by jets from an active nucleus in the 
peculiar galaxy NGC 4438. The bubbles form because jets 
of gas, not directly visible, are probably outflowing 
from an accretion disk around a supermassive black hole. 
When the jets from the accretion disk, which is the 
brightest source in the image, run into the galaxy's gas,
they form expanding bubbles which shine. There are 2 jets 
shot out in opposite directions, and therefore 2 bubbles.
The second bubble is faint and located further from the 
nucleus, and is barely visible in the image. There is 
more gas on one side of the nucleus than the other, so the 
collision is more violent and the bubble is much brighter 
on that side. The darker bands arise from dust which blocks 
much of the light from the galaxy center. This is a nearby 
weak example of an active galactic nucleus, which is the 
phenomenon responsible for powerful quasars and radio galaxies.
This galaxy is located in the Virgo Cluster, which is 
50 million light years from earth. The bright bubble is 
800 light-years in diameter.
  [NGC 4438 HST]

 NGC 4438 HST Nucleus and Larger View  

  [NGC 4438 Digital Sky Survey]

 NGC 4438 Sky Survey

Image of NGC 4438 from 
Palomar Digital Sky Survey with
outline of HST WFPC2 superposed.
  [NGC 4438 HST Full WFPC2]

 NGC 4438 HST Full WFPC2

Image of NGC 4438 from HST WFPC2.


Project Scientists for HST images are Jeff Kenney and Elizabeth Yale.
Page designed and maintained by Jeff Kenney .
Send comments by email to kenney@astro.yale.edu.

HST images © NASA and STScI, 2000. Digital Sky Survey image © Caltech. Last updated:September 3, 2000. __________________________________________________________________________