Galaxies: Radio Galaxies

Above are shown images of the area around the peculiar galaxy pair ESO 295-IG022, at the centre of the poor cluster Abell S0102. The first image shows contours of ATCA 1384 MHz radio continuum emission superimposed on a ROSAT hard X-ray PSPC image. The second image shows the same radio data (grey) overlayed with optical DSS2 contours.

• Though the two interacting galaxies are obvious in the optical, one can also see that the southern galaxy is itself interacting, optical filaments being visible to the west, enveloping a nearby companion. Also a double nucleus is seen at the dead centre of the southern galaxy itself.
  
  
• The radio observations show what appears to be a bipolar, fairly assymetrical, twin jet radio galaxy, associated with the southern system. The fact that the northern tip of the radio feature appears coincident (though not exactly) with the northern galaxy, may indicate the presence of a one-sided jet from the northen system, or may just be a remarkable coincidence.
  
  
• The radio jets have projected lengths of around 100 kpc, and have velocities of at least 1000 km/s. The bending of the jets is likely due to the southern ESO 295-IG022 galaxy moving through the ICM at close to 200 km/s.
  
  
• The X-ray observations indicate relatively cool diffuse emission consistent with that of a group or poor cluster. The X-ray-radio anticorrelation is suggestive of channeling effects taking place, i.e. the jets are able to punch holes, and displace the X-ray emitting cluster gas.