Unlike most spiral galaxies of the Virgo Cluster, NGC 4651 is rich in neutral hydrogen that also extends beyond the optical disk, and its star formation is typical of a galaxy of its type. Unlike most spiral galaxies of the Virgo Cluster, NGC 4651 is rich in neutral hydrogen that also extends beyond the optical disk, and its star formation is typical of a galaxy of its type. Studies of the distribution of neutral hydrogen with radio telescopes reveal distortions in the outer regions of NGC 4651 and a clump of gas associated with a dwarf galaxy that may have been formed in the event that produced the aforementioned stellar streams. This member of the Virgo Cluster, located at the edge of the Virgo Cluster, is known as the Umbrella Galaxy because of the umbrella-shaped structure that extends eastward from its disk and is composed of stellar streams. It is the remnant of a much smaller galaxy that was torn apart by the tidal forces of NGC 4651, which explains why NGC 4651 is listed in Halton Arp’s Atlas of Special Galaxies as Arp 189 -Galaxy with Filaments-.
What kind of galaxy is NGC 4651?
Radio telescope studies of the distribution of neutral hydrogen show distortions in the outer regions of NGC 4651 and a clump of gas associated with a dwarf galaxy that may have been formed in the event that produced the aforementioned stellar streams. It is difficult to detect a galaxy with a brightness of about 11 magnitudes with a small-calibre telescope. A remarkable collaboration of amateur and professional astronomers has begun imaging faint structures around bright galaxies, suggesting that even in nearby galaxies, tidal stellar streams are common signs of such galactic mergers. But the remnants of the small galaxies that are crucial to understanding the food chain process are very faint and difficult to observe.
The “cosmic food chain”, in which large galaxies cannibalise small galaxies, is already widely known.
Who discovered NGC 1316?
The team led by Enrichetta Iodice (INAF – Osservatorio di Capodimonte, Naples, Italy) previously observed this area with the VST and discovered a faint light bridge between NGC 1399 and the smaller galaxy NGC 1387.The team, led by Enrichetta Iodice (INAF – Osservatorio di Capodimonte, Naples, Italy), previously observed this area with the VST, detecting a faint bridge of light between NGC 1399 and the smaller galaxy NGC 1387.NGC 1316, also known as Fornax A, is one of the strongest and largest radio sources in the sky, with radio lobes extending over several degrees of the sky (well outside the Hubble image). The team, led by Enrichetta Iodice (INAF – Osservatorio di Capodimonte, Naples, Italy), has previously observed this area with the VST, detecting a faint bridge of light between NGC 1399 and the smaller galaxy NGC 1387.NGC 1316, also known as Fornax A, is one of the strongest and largest radio sources in the sky, with radio lobes extending across several degrees of the sky (well outside the Hubble image). In the late 1970s, François Schweizer studied NGC 1316 in detail and found that it looks like a small elliptical galaxy with some unusual dust lanes embedded in a much larger envelope of stars. The latter feature makes NGC 1316 a remarkable place to test the extragalactic distance scale, since SNe Ia matter for cosmological distances and NGC 1316 is one of the nearest massive galaxies after merger.
How big is NGC 1316?
NGC 1316 (also known as Fornax A) is a lenticular galaxy in the constellation Fornax about 60 million light years away. The loops and plumes (the so-called “tidal features”) are thought to be the stellar remnants of other spiral galaxies that merged with NGC 1316 sometime in the last few billion years. The combination of Hubble’s superb spatial resolution and the sensitivity of the Advanced Camera for Surveys (ACS), which was installed aboard Hubble in 2002 and used for these images, provided uniquely accurate measurements of a class of red star clusters in NGC 1316. The survey suggests that NGC 1316 is a giant elliptical galaxy that in some way contains dark dust trails normally found in spiral galaxies.
