The NASA/ESA Hubble Space Telescope provides us with a spectacular image of the bright star-forming ring that surrounds the heart of the barred spiral galaxy NGC 1097. In this image, the larger-scale structure of the galaxy is barely visible: its comparatively dim spiral arms, which surround its heart in a loose embrace, reach out beyond the edges of this frame.
This face-on galaxy, lying 45 million light-years away from Earth in the southern constellation of Fornax (The Furnace), is particularly attractive for astronomers. NGC 1097 is a Seyfert galaxy. Lurking at the very center of the galaxy, a supermassive black hole 100 million times the mass of our sun is gradually sucking in the matter around it. The area immediately around the black hole shines powerfully with radiation coming from the material falling in.
The distinctive ring around the black hole is bursting with new star formation due to an inflow of material toward the central bar of the galaxy. These star-forming regions are glowing brightly thanks to emission from clouds of ionized hydrogen. The ring is around 5000 light-years across, although the spiral arms of the galaxy extend tens of thousands of light-years beyond it.
NGC 1097 is also pretty exciting for supernova hunters. The galaxy experienced three supernovae (the violent deaths of high-mass stars) in the 11-year span between 1992 and 2003. This is definitely a galaxy worth checking on a regular basis.
However, what it is really exciting about NGC 1097 is that it is not wandering alone through space. It has two small galaxy companions, which dance “the dance of stars and the dance of space” like the gracious dancer of the famous poem The Dancer by Khalil Gibran.
The satellite galaxies are NGC 1097A, an elliptical galaxy orbiting 42 000 light-years from the center of NGC 1097 and a small dwarf galaxy named NGC 1097B. Both galaxies are located out beyond the frames of this image and they cannot be seen. Astronomers have indications that NGC 1097 and NGC 1097A have interacted in the past.
This picture was taken with Hubble’s Advanced Camera for Surveys using visual and infrared filters.
Wiki:-
NGC 1097 (also known as Caldwell 67) is a barred spiral galaxy about 45 million light-years away in the constellation Fornax. It was discovered by William Herschel on 9th October 1790. Three supernovae (SN 1992bd, SN 1999eu, and SN 2003B) have been observed in NGC 1097.
NGC 1097 is also a Seyfert galaxy. Deep photographs by Wolstencroft & Zealey (1975), Arp (1976), and Lorre (1978) revealed four narrow optical jets that appear to emanate from the nucleus. Arp interpreted these as manifestations of the (currently weak) active nucleus. Subsequent analysis of the brightest jet's radio-to-X-ray spectral energy distribution by Carter, Allen & Malin (1984), Wehrle, Keel, & Jones (1997) and Higdon & Wallin (2003) were able to rule out synchrotron and thermal free-free emission. The optical jets are in fact composed of stars. The failure to detect atomic hydrogen gas in the jets (under the assumption that they were an example of tidal tails) using deep 21 cm HI imaging with the Very Large Array radio telescope and numerical simulations led to the current interpretation that the jets are actually the shattered remains of a cannibalized dwarf galaxy (Higdon & Wallin 2003).
Like most massive galaxies, NGC 1097 has a supermassive black hole at its center. Around the central black hole is a ring of star-forming regions with a network of gas and dust that spirals from the ring to the black hole.
NGC 1097 has two satellite galaxies. Dwarf elliptical galaxy NGC 1097A is the larger of the two. It is a peculiar elliptical galaxy that orbits 42,000 light-years from the center of NGC 1097. Dwarf galaxy NGC 1097B, the outermost one, was discovered by its HI emission (5 x 10^6 solar masses; Higdon & Wallin 2003), and appears to be a typical dwarf irregular. Little else is known about it.
Image Gallery of NGC 1097
 |
| Colour-composite image of the central 5,500 light-years wide region of the spiral galaxy NGC 1097, obtained with the NACO adaptive optics on the VLT. Credit: ESO |
 |
| NGC 1097 seen by the Spitzer Space Telescope |
 |
| Star forming ring in NGC 1097. HST. 0.9′ view |