NGC 6338 is a large lenticular galaxy located in the constellation Draco. It is located at an estimated distance of 392 million light years from Earth[1] and was discovered by William Herschel in 1789. According to Herschel, he mentioned, "the object is faint, small and round with a little brighter middle."[2]

NGC 6338
The lenticular galaxy, NGC 6338.
Observation data (J2000 epoch)
ConstellationDraco
Right ascension17h 15m 22.99s
Declination+57° 24′ 40.26″
Redshift0.027303
Heliocentric radial velocity8,185 km/s
Distance392 Mly (120.18 Mpc)
Apparent magnitude (B)14.2
Characteristics
TypecD;S0; PEG blazar
Size78.16 kiloparsecs (254,900 light-years)
(diameter; 2MASS K-band total isophote)[1]
Other designations
PGC 59947, UGC 10784, CGCG 299-066, MCG +10-24-116, WBL 6356-002

Characteristics

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NGC 6338 is the brightest cluster galaxy in the NGC 6338 group, shown merging with another galaxy group.[3][4] It forms a pair with MCG +10-24-117.[5] It has an ellipsoidal appearance based on findings of a stellar component revolving around a major axis.[6] NGC 6338 is also more luminous compared to other members with estimated absolute magnitudes of MB = -22.2 and MV = -21.92. NGC 6338 also contains a central bright source when seen in X-rays.[5] A double nucleus is present in NGC 6338.[7]

The nucleus of NGC 6338 is active and it is classified both a LINER[8] as well as a Fanaroff-Riley class type 0 radio galaxy.[9] The most accepted theory for this energy source for active galactic nuclei is the presence of an accretion disk around a giant black hole. Furthermore, NGC 6338 has both young and old radio lobes, with radiative ages of 200 and 50 million years old. It also has a small parsec-scale radio jet with radio emission in its core.[3] There are also X-ray cavities located both northeast and southwest of the galaxy's nucleus.[5]

Based on narrow band imaging taken with Hubble Space Telescope, NGC 6338 contains emission originating from two compact clouds in its galactic center and three filaments along its minor axis. The filaments have a projected outward extension of ~ 13.5" and a total Hα flux of 1.78 x 10-14 erg s-1 cm-2.[6]

References

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  1. ^ a b "By Name NASA/IPAC Extragalactic Database". ned.ipac.caltech.edu. Retrieved 2024-10-13.
  2. ^ "New General Catalog Objects: NGC 6300 - 6349". cseligman.com. Retrieved 2024-10-13.
  3. ^ a b Schellenberger, Gerrit; O’Sullivan, Ewan; Giacintucci, Simona; Vrtilek, Jan; David, Laurence P.; Combes, Francoise; Bîrzan, Laura; Pan, Hsi-An; Lin, Lihwai (2023-05-01). "Feedback in the Extremely Violent Group Merger NGC 6338". The Astrophysical Journal. 948 (2): 101. arXiv:2303.08833. Bibcode:2023ApJ...948..101S. doi:10.3847/1538-4357/acc52e. ISSN 0004-637X.
  4. ^ "Chandra :: Photo Album :: NGC 6338 :: December 17, 2019". chandra.harvard.edu. Retrieved 2024-10-13.
  5. ^ a b c Pandge, M. B.; Vagshette, N. D.; David, L. P.; Patil, M. K. (January 2012). "Systematic study of X-ray cavities in the brightest galaxy in the Draco constellation NGC 6338". Monthly Notices of the Royal Astronomical Society. 421 (1): 808. arXiv:1202.1364. Bibcode:2012MNRAS.421..808P. doi:10.1111/j.1365-2966.2011.20358.x. ISSN 0035-8711.
  6. ^ a b O’Sullivan, Ewan; Schellenberger, Gerrit; Burke, D J; Sun, Ming; Vrtilek, Jan M; David, Laurence P; Sarazin, Craig (2019-06-24). "Building a cluster: shocks, cavities, and cooling filaments in the group–group merger NGC 6338". Monthly Notices of the Royal Astronomical Society. 488 (2): 2925–2946. arXiv:1906.07710. doi:10.1093/mnras/stz1711. ISSN 0035-8711.
  7. ^ Wang, Yu; Lui, Fuyao; Shen, Zhiqiang; Wang, Jingying; Hu, Dan; Xu, Hai-Guang (2019-01-10). "Revealing a Head-on Major Merger in the Nearby NGC 6338 Group with Chandra and VLA Observations". The Astrophysical Journal. 870 (2): 132. arXiv:1901.08769. Bibcode:2019ApJ...870..132W. doi:10.3847/1538-4357/aaf234. ISSN 0004-637X.
  8. ^ Gomes, J.M.; Papaderos, P.; Kehrig, C.; Vilchez, J.M.; Lehnert, M.D.; Sanchez, S.F. (April 2016). "Warm ionized gas in CALIFA early-type galaxies 2D emission-line patterns and kinematics for 32 galaxies" (PDF). Astronomy & Astrophysics. 588 (A68): 58. arXiv:1511.02191. Bibcode:2016A&A...588A..68G. doi:10.1051/0004-6361/201525976.
  9. ^ Torresi, E; Grandi, P; Capetti, A; Baldi, R D; Giovannini, G (2018-03-03). "X-ray study of a sample of FR0 radio galaxies: unveiling the nature of the central engine". Monthly Notices of the Royal Astronomical Society. 476 (4): 5535–5547. arXiv:1802.08581. doi:10.1093/mnras/sty520. ISSN 0035-8711.
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