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Comet Galaxy

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Comet Galaxy
The Comet Galaxy, as taken by the Hubble Space Telescope
Observation data (J2000 epoch)
ConstellationSculptor
Right ascension23h 51m 44.03s[1][2]
Declination−26° 03′ 59.6″[1][2]
Redshift0.2265[1][2]
Heliocentric radial velocity67,753±89 km/s[3]
Galactocentric velocity67,778±89 km/s[3]
Distance3,250 ± 227.7 Mly (996.6 ± 69.8 Mpc)h−1
0.6774

(Comoving)[3]
2.777 Gly (0.8514 Gpc)h−1
0.6774

(Light-travel)[3]
Group or clusterAbell 2667
Apparent magnitude (B)18.642[4][2]
Characteristics
TypedIrr[5]
Mass3.8×108 (stellar)[5] M☉
Size170,000 ly × 142,000 ly
(52.2 kpc × 43.5 kpc)[3][a]
Apparent size (V)0.18′ × 0.15′[3]
Notable featuresStripped stream of bright blue knots and diffuse wisps of young stars[6]
Other designations
2dFGRS TGS132Z144[3], EQ J235144-260358[2], WISEA J235144.05-260357.9[3], LEDA 3234374,[3]

The Comet Galaxy[6] (EQ J235144-260358)[2] is a peculiar spiral galaxy located 996.6 megaparsecs (3.3 billion light-years) from Earth in the galaxy cluster Abell 2667 and the constellation Sculptor.[3] This galaxy has slightly more stellar mass than the Milky Way. It was detected on 2 March 2007 with the Hubble Space Telescope.[1]

The galaxy is currently traveling through the galactic cluster at 3.6 million km/h (2.17 million mi/h), and as a result is being stripped of much of its matter as a result of the cluster's tidal forces.[5]

Structure

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The Comet Galaxy is a unique, peculiar galaxy that features an extended stream of interstellar gas, blue knots (or large clumps of matter), and wisps of bright-blue young stars.[5] It is currently traveling through Abell 2667 at 3.6 million km/h (1,000 km/s[5]), and as a result of the gravitational forces of the cluster, much of the galaxy's matter is being stripped out into a long tail, similar to a comet; as a result, one of the galaxy's arms appears flatter then the surrounding arms, while the tail contains numerous bright starburst regions.[5]

Its isophotal diameter is currently unknown. Based off its apparent size of 10.8 arcseconds for the main galaxy, along with the galaxy's distance from Earth, it approximately corresponds to a diameter of 52.2 kiloparsecs (170,000 light-years), thus making it slightly larger than the Andromeda Galaxy.[3][a]

Fate

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The Сomet Galaxy is currently being ripped apart as a result of traveling through a large galaxy cluster at speeds of greater than 2 million mph.[5] As the galaxy speeds through, its gas and stars are being stripped away by the tidal forces and charged particles exerted by the cluster.[6] Also contributing to this destructive process is the pressure of the cluster's hot intergalactic gas and plasma, reaching temperatures as high as 100 million degrees.[6] Scientists estimate that the total duration of the transformation process is close to one billion years;[6] the galaxy is seen to be roughly 400 million years into this process.[3][5]

In spite of the galaxy's large mass, the spiral will inevitably lose majority of its gas and dust, resulting in a gas-poor lenticular or elliptical galaxy with an older population of red stars.[3] The finding sheds light on the process by which some gas-rich galaxies might evolve into gas-poor galaxies over billions of years. Observations also reveal one mechanism that may result in intergalactic stars.[2][5]

See also

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Notes

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  1. 1 2 Calculated based on minor and major angular diameters and the quoted comoving distance:

References

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  1. 1 2 3 4 Cortese, L. (2007). "The strong transformation of spiral galaxies infalling into massive clusters atz≈ 0.2". Monthly Notices of the Royal Astronomical Society. 376 (1): 157–172. arXiv:astro-ph/0703012. Bibcode:2007MNRAS.376..157C. doi:10.1111/j.1365-2966.2006.11369.x. S2CID 17152868.
  2. 1 2 3 4 5 6 7 "2dFGRS TGS132Z144". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-12-20.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 WISEA J235144.05-260357.9 on NASA/IPAC Extragalactic Database
  4. ↑ Colless, Matthew; Dalton, Gavin; Maddox, Steve; Sutherland, Will; Norberg, Peder; Cole, Shaun; Bland-Hawthorn, Joss; Bridges, Terry; Cannon, Russell; Collins, Chris; Couch, Warrick; Cross, Nicholas; Deeley, Kathryn; De Propris, Roberto; Driver, Simon P.; Efstathiou, George; Ellis, Richard S.; Frenk, Carlos S.; Glazebrook, Karl; Jackson, Carole; Lahav, Ofer; Lewis, Ian; Lumsden, Stuart; Madgwick, Darren; Peacock, John A.; Peterson, Bruce A.; Price, Ian; Seaborne, Mark; Taylor, Keith (2001). "The 2dF Galaxy Redshift Survey: Spectra and redshifts". Monthly Notices of the Royal Astronomical Society. 328 (4): 1039. arXiv:astro-ph/0106498. Bibcode:2001MNRAS.328.1039C. doi:10.1046/j.1365-8711.2001.04902.x.
  5. 1 2 3 4 5 6 7 8 9 Fumagalli, Mattia; Gavazzi, G.; Scaramella, R.; Franzetti, P. (April 2011), "Constraining the ages of the fireballs in the wake of the dIrr galaxy VCC 1217/IC 3418", Astronomy & Astrophysics, 528: 9, arXiv:1011.1665, Bibcode:2011A&A...528A..46F, doi:10.1051/0004-6361/201015463, S2CID 119240960, A46
  6. 1 2 3 4 5 "Hubble sees "Comet Galaxy" being ripped apart by galaxy cluster". ESA/Hubble. L. Cortese. 2 March 2007.