NGC 720
X-rays source | |
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Other designations | |
MCG -02-05-068, PGC 6983[1] |
NGC 720 is an
Characteristics
NGC 720 is an elliptical galaxy with elongated shape in the northwest to southeast axis as seen from Earth.
Observations made in 1996 suggested the galaxy had 660 ±190 globular clusters in the central 30kpc, a number considered small for such a galaxy. The allocation of the clusters resembled the ellipticity, position angle and surface brightness of the galaxy.[9] However, in 2012 it was observed that the blue globular clusters subpopulation had a similar slope with the X-ray surface brightness profile.[10] Further observations by the SLUGGS Survey (2016), with wider field data, raised the number of globular clusters in the galaxy to 1489 ± 96 and their distribution was less elliptical than the surface profile of the galaxy. The clusters have bimodal distribution as far as color is concerned, with the clusters characterised as red or blue, with the blue clusters having a stronger connection with the galactic halo.[11]
Optical long slit
Nearby galaxies
NGC 720 is the foremost galaxy in a small galaxy group, the NGC 720 group, which also includes the galaxy Arp 4.[13] NGC 720 lies at the centre of the group and the rest of the galaxies of the group are dwarf galaxies, which are at least 2 mag fainter than NGC 720. There is extended intragroup X-ray emission. The high fraction of early-type galaxies suggest that NGC 720 may be a fossil group, despite its low mass.[14] Further away lie the edge-on spiral galaxy NGC 681, NGC 701, and NGC 755.[13]
Gallery
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DSS image of NGC 720
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Pan-STARRS image of NGC 720
References
- ^ a b c d e f g h i "NASA/IPAC Extragalactic Database". Results for NGC 720. Retrieved 2016-01-18.
- ^ Seligman, Courtney. "NGC 720 (= PGC 6983)". Celestial Atlas. Retrieved 19 November 2018.
- ^ ISBN 978-0521858939.
- doi:10.1086/117719.
- ^ "NGC 720: Chandra Casts Cloud On Alternative To Dark Matter". chandra.harvard.edu. Harvard-Smithsonian Center for Astrophysics/NASA. October 22, 2002. Retrieved 20 November 2018.
- S2CID 18833087.
- S2CID 11550337.
- S2CID 119461736.
- Bibcode:1996A&A...308..704K.
- S2CID 119235037.
- .
- hdl:10183/98765.
- ^ S2CID 119194025. Archived from the originalon 31 January 2016. Retrieved 21 November 2018.
- S2CID 9177976.
External links
- NGC 720 on
- NGC 720 on SIMBAD