Page last updated Mar 13, 2020|
Updated entry for PGC 47660
PGC 47660 (= PGC 234567 = ESO 021-004)
A magnitude 13(?) spiral galaxy (type S(rs)a) in Chamaeleon (RA 13 32 40.9, Dec -77 50 38)
Note About ESO Designation: I usually use NGC/IC or PGC/LEDA designations for galaxies, but in this case the HST press release only uses the ESO designation, hence its use in the title for this entry.
Physical Information: Based on a recessional velocity relative to the Cosmic Microwave Background of 3060 km/sec (and H0 = 70 km/sec/Mpc), PGC 47660 is about 140 to 145 million light years away. Given that and its apparent size of about 2.25 by 0.5 arcmin (based on the images below), the galaxy is about 90 to 95 thousand light years across. It has an active galactic nucleus, presumably due to material falling into the supermassive black hole at its center.
Above, a 12 arcmin wide DSS image centered on PGC 47660
Below, a 2.75 arcmin wide image of the galaxy (Image Credit ESA/Hubble & NASA, D. Rosario et al.)
Below, a 1.4 by 2.5 arcmin wide image of the galaxy (Image Credit as for the image above)
(North is on the right, to allow for more detail)
Below, a 0.75 arcmin wide image of the center of the galaxy (Image Credit as for the image above)
PGC 47808 (= Arp 36)
A magnitude 15.1 spiral galaxy (type SBb? pec) in Canes Venatici (RA 13 34 15, Dec +31 25 29)
Physical Information: Based on a recessional velocity of 5015 km/sec (and H0 = 70 km/sec/Mpc), PGC 47808 is about 230 to 235 million light years away, in good agreement with a single redshift-independent distance estimate of about 240 million light years. Given that and an apparent size of about 1.15 by 0.5 arcmin (from the images below), the galaxy is about 80 thousand light years across. It is used as an example of an S- or Integral-sign shaped spiral galaxy in Arp's Atlas.
Above, a 12 arcmin wide SDSS image centered on PGC 47808
Below, a 1.6 arcmin wide SDSS image of the galaxy