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> Galaxy NGC 4650A in Centaurus

Galaxy NGC 4650A in Centaurus

author: Nasa/Hubble heritage team/Novapix

reference: a-gax46-50002

Image Size 300 DPI: 5 * 12 cm

Located about 130 million light-years away, NGC 4650A is one of only 100 known polar-ring galaxies. Their unusual disk-ring structure is not yet understood fully. One possibility is that polar rings are the remnants of colossal collisions between two galaxies sometime in the distant past, probably at least 1 billion years ago. During the collision the gas from a smaller galaxy would have been stripped off and captured by a larger galaxy, forming a new ring of dust, gas, and stars, which orbit around the inner galaxy almost at right angles to the larger galaxy's disk. This is the vertical polar ring which we see almost edge-on in Hubble's Wide Field Planetary Camera 2 image of NGC 4560A, created using 3 different color filters (which transmit blue, green, and near-infrared light). The ring appears to be highly distorted and the presence of bluish, young stars below the main ring on one side and above on the other shows that the ring is warped and does not lie in one plane.

Keywords for this photo:

ASTRONOMY - CENTAURUS - GALAXY - HST - HUBBLE SPACE TELESCOPE - NGC 4650A - POLAR RING GALAXY - SOUTHERN HEMISPHERE - SPIRAL GALAXY - STAR -