NGC 7418

NGC 7418
NGC 7418 hst 08599 814.png
NGC 7418 by Hubble Space Telescope
Observation data (J2000 epoch)
ConstellationGrus
Right ascension22h 56m 36.2s[1]
Declination−37° 01′ 48.3″[1]
Redshift0.004837 ± 0.000017 [1]
Helio radial velocity1,450 ± 5 km/s[1]
Distance59.1 ± 8.5 Mly (18.2 ± 2.6 Mpc)[1]
Apparent magnitude (V)11.0
Characteristics
TypeSAB(rs)cd [1]
Apparent size (V)3′.5 × 2′.6[1]
Other designations
ESO 406- G025, MCG -06-50-013, PGC 70069[1]

NGC 7418 is an intermediate spiral galaxy located in the constellation Grus. It is located at a distance of circa 60 million light years from Earth, which, given its apparent dimensions, means that NGC 7418 is about 60,000 light years across.[1] It was discovered by John Herschel on August 30, 1834.[2]

Characteristics

NGC 7418 has a bright nucleus incorporated into a bar. The bar appears strong in the infrared H-band while in the optical wavelengths it appears weaker or even unbarred. The spiral arms of the galaxy emanate from the end of the bar. The galaxy has four grand design spiral arms. Their inner parts have knots while the outermost are smooth.[3] The galaxy is seen with an inclination of 42 degrees.[4]

In the centre of NGC 7418 is believed to lie a supermassive black hole with an estimated mass between 1 and 15 million (106.58 ± 0.59)M☉, based on the spiral pitch angle.[5] The centre of the galaxy has also been found to host a massive stellar cluster, with an estimated mass of nearly 60 million (107.78 ± 0.19) M☉.[6] The existence of this nuclear star cluster doesn't rule out the existence of a supermassive black hole. Galaxies like the Milky Way and the Andromeda Galaxy have been found to host both.[5] The stellar population at the nucleus of NGC 7418 has been found to be quite young, with mean age less than 100 million years, indicating recent star forming activity.[7]

NGC 7418, SN 1983 Z에서 초신성 하나가 관측되었습니다.그것은 L. E. 곤잘레스에 의해 핵에서 서쪽으로 11인치, 남쪽으로 52인치 떨어진 Cerro El Roble에서 발견되었다.1983년 9월 3일 겉보기 등급은 15.[8]5였다.

가까운 은하

NGC 7418은 IC 1459 은하군으로 알려진 은하군의 구성원입니다.이것은 IC 1459를 중심으로 한 느슨한 은하군이며 많은 나선은하를 [9]포함하고 있습니다.다른 구성원으로는 NGC 7418A, NGC 7421, IC 5264, IC 5269, IC 5269B, IC 5270, IC 5273 [10]등이 있습니다.NGC 7421은 19.5분 거리에 있고 NGC 7418A는 하늘에서 [11]볼 때 북쪽으로 16.5분 거리에 있습니다.이 그룹은 NGC 7582 그룹과 함께 은하 [9]밀도가 높은 영역인 Grus 구름을 형성합니다.Grus 구름은 인근의 Pavo-Indus 구름과 함께 국부 초은하단과 Pavo-Indus 초은하단 [12]사이에 있습니다.

이 그룹은 은하간 매질로부터의 확산 X선 방출과 HI 방출을 특징으로 한다.양쪽의 존재에 근거해, 그룹은 다른 서브 그룹으로부터 조립하는 초기 단계에 있는 것이 제안되고 있다.세 개의 HI 구름은 IC 5270 근처와 NGC 7418 근처에 위치해 있으며, 총 질량은 6×108☉ M입니다.이러한 HI 구름은 [9]은하에서 떨어져 나온 가스에서 상호작용의 결과로 형성된 것으로 추정됩니다.

NGC 7418(HST - Aladin 소프트웨어)

레퍼런스

  1. ^ a b c d e f g h i "NASA/IPAC Extragalactic Database". Results for NGC 7418. Retrieved 2019-01-18.
  2. ^ Seligman, Courtney. "NGC 7418 (= PGC 70069)". Celestial Atlas. Retrieved 19 November 2018.
  3. ^ Eskridge, Paul B.; Frogel, Jay A.; Pogge, Richard W.; Quillen, Alice C.; Berlind, Andreas A.; Davies, Roger L.; DePoy, D. L.; Gilbert, Karoline M.; Houdashelt, Mark L.; Kuchinski, Leslie E.; Ramirez, Solange V.; Sellgren, K.; Stutz, Amelia; Terndrup, Donald M.; Tiede, Glenn P. (November 2002). "Near-Infrared and Optical Morphology of Spiral Galaxies". The Astrophysical Journal Supplement Series. 143 (1): 73–111. arXiv:astro-ph/0206320. Bibcode:2002ApJS..143...73E. doi:10.1086/342340. S2CID 15491635.
  4. ^ Munoz-Mateos, J. C.; Gil de Paz, A.; Boissier, S.; Zamorano, J.; Jarrett, T.; Gallego, J.; Madore, B. F. (April 2007). "Specific Star Formation Rate Profiles in Nearby Spiral Galaxies: Quantifying the Inside-Out Formation of Disks". The Astrophysical Journal. 658 (2): 1006–1026. arXiv:astro-ph/0612017. Bibcode:2007ApJ...658.1006M. doi:10.1086/511812. S2CID 41735449.
  5. ^ a b Davis, Benjamin L.; Berrier, Joel C.; Johns, Lucas; Shields, Douglas W.; Hartley, Matthew T.; Kennefick, Daniel; Kennefick, Julia; Seigar, Marc S.; Lacy, Claud H. S. (20 June 2014). "The Black Hole Mass Function Derived from Local Spiral Galaxies". The Astrophysical Journal. 789 (2): 124. arXiv:1405.5876. Bibcode:2014ApJ...789..124D. doi:10.1088/0004-637X/789/2/124. S2CID 119302157.
  6. ^ Walcher, C. J.; van der Marel, R. P.; McLaughlin, D.; Rix, H.-W.; Boker, T.; Haring, N.; Ho, L. C.; Sarzi, M.; Shields, J. C. (January 2005). "Masses of Star Clusters in the Nuclei of Bulgeless Spiral Galaxies". The Astrophysical Journal. 618 (1): 237–246. arXiv:astro-ph/0409216. Bibcode:2005ApJ...618..237W. doi:10.1086/425977. S2CID 14365007.
  7. ^ Walcher, C. J.; Boker, T.; Charlot, S.; Ho, L. C.; Rix, H.-W.; Rossa, J.; Shields, J. C.; van der Marel, R. P. (October 2006). "Stellar Populations in the Nuclei of Late-Type Spiral Galaxies". The Astrophysical Journal. 649 (2): 692–708. arXiv:astro-ph/0604138. Bibcode:2006ApJ...649..692W. doi:10.1086/505166. S2CID 18882700.
  8. ^ "Circular No. 3867". International Astronomical Union Circular. Central Bureau for Astronomical Telegrams. 23 September 1983.
  9. ^ a b c Serra, P.; et al. (25 July 2015). "ASKAP H i imaging of the galaxy group IC 1459". Monthly Notices of the Royal Astronomical Society. 452 (3): 2680–2691. arXiv:1506.04399. Bibcode:2015MNRAS.452.2680S. doi:10.1093/mnras/stv1326.
  10. ^ Makarov, Dmitry; Karachentsev, Igor (21 April 2011). "Galaxy groups and clouds in the local (z∼ 0.01) Universe". Monthly Notices of the Royal Astronomical Society. 412 (4): 2498–2520. arXiv:1011.6277. Bibcode:2011MNRAS.412.2498M. doi:10.1111/j.1365-2966.2010.18071.x. S2CID 119194025.
  11. ^ de Vaucouleurs, G.; de Vaucouleurs, A.; Corwin, J. R. (1976). "Second reference catalogue of bright galaxies". Second Reference Catalogue of Bright Galaxies. 1976. Bibcode:1976RC2...C......0D.
  12. ^ Fouque, P.; Proust, D.; Quintana, H.; Ramirez, A.; Proust, D.; Quintana, H.; Ramirez, A. (1993). "Dynamics of the Pavo-Indus and Grus Clouds of Galaxies" (PDF). Astronomy and Astrophysics Supplement Series. 100 (3): 493–500. Bibcode:1993A&AS..100..493F.{{cite journal}}: CS1 maint: 여러 이름: 작성자 목록(링크)

외부 링크