Contains:  Other
NGC 6217 - Simbad map, astroeyes

NGC 6217 - Simbad map

NGC 6217 - Simbad map, astroeyes

NGC 6217 - Simbad map

Description

NGC 6217 long ago was marked as an active galaxy. As Atlas of Peculiar Galaxies No. 185 in Arp's catalogue, it had been put near the jet category just from optical inspection. Forty years later it turns out to have an X-ray jet at almost a right angle to the suspected optical ejection. Serendipitously there is a white dwarf located quite close to NGC 6217 which attracted many X-ray exposures of the field. The figure below shows an X-ray exposure in which there is a conspicuous X-ray jet emerging from the galaxy. X-ray jets of this strength are rather rare and serve to emphasize the unusually active nature of NGC 6217.



The most extraordinary feature of NGC 6217, however, is that flanking it are three quasars . Two of these are aligned longitudinally across the active galaxy within 4°, and the redshifts of the two are z = 0.376 and 0.380. The probability of finding by accident three sources this bright, this close to any given point in the sky is about 6 × 10-3.

The third quasar falls only within 27° of this alignment and has z = 0.358, not as conclusive as the well aligned pair but certainly adding to the significance of the association.

The P.A. of the z = 0.376 quasar is 109° from NGC 6217. This is in the direction of Hickson compact group 84 (P.A. = 117) and in the general direction of the cluster A2248, which have redshifts z = 0.056 and 0.066, respectively. Arp suggests that there is one ejection line along the paired quasars to A2248 and one along the X-ray jet from NGC 6217 to the clusters A2181 and A2256.

Arp 185 is an interesting galaxy. Not immediately obvious but just barely visible in my image, are the faint outer spiral arms/ring. The galaxy is classified SB(r)bc (inner ringed spiral) and is mag. 12 with a s.b of 14 mag/square arcmin.

I find Arp's arguements somewhat compelling. His reasoning may, or may not be flawed but there can be no doubting his determination to make his views known in the face of overwhelming and almost total opposition.

Comments

Revisions

  • NGC 6217 - Simbad map, astroeyes
    Original
  • Final
    NGC 6217 - Simbad map, astroeyes
    B
  • NGC 6217 - Simbad map, astroeyes
    C

Histogram

NGC 6217 - Simbad map, astroeyes