Super star cluster

From Wikipedia, the free encyclopedia
Jump to: navigation, search

A super star cluster (SSC) is a very massive young open cluster that is thought to be the precursor of a globular cluster.[1] They typically contain a very large number of young, massive stars that ionize a surrounding H II region, similar to our Milky Way's so-called "Ultra dense H II regions (UDHIIs)".[2] An SSC's H II region is in turn surrounded by a cocoon of dust. In many cases, the stars and the H II regions will be invisible to optical observations due to high levels of extinction. As a result, the youngest SSCs are best observed in radio and infrared.[3]

The unique characteristics of SSCs are their large electron densities n_e=10^310^6 cm^{-3} and pressures P/k_b=10^710^{10} K cm^{-3}.[3]

List[edit]

Name Galaxy Comments Notes
Westerlund 1 (Wd1) Milky Way Galaxy First SSC discovered in our galaxy. [4]
NGC 3603 Milky Way Galaxy [5]
R136 Large Magellanic Cloud (LMC) The prototype SSC [6]
NGC 1569 Galaxy contains two SSCs [7]

References[edit]

  1. ^ Gallagher & Grebel (2002). "Extragalactic Star Clusters: Speculations on the Future". Extragalactic Star Clusters, IAU Symposium 207: 207. arXiv:astro-ph/0109052. Bibcode:2002IAUS..207..745G. 
  2. ^ Kobulnicky, Henry A. & Johnson, Kelsey E. (1999). "Signatures of the Youngest Starbursts: Optically Thick Thermal Bremsstrahlung Radio Sources in Henize 2-10". ApJ 527 (1): 154–166. arXiv:astro-ph/9907233. Bibcode:1999ApJ...527..154K. doi:10.1086/308075. 
  3. ^ a b Johnson (2004). "Extragalactic Ultracompact HII Regions: Probing the Birth Environments of Super Star Clusters". Astronomical Society of the Pacific Conference Series 527: 322. arXiv:astro-ph/0405125. Bibcode:2004ASPC..322..339J. 
  4. ^ Clark, J. S.; Negueruela, I.; Crowther, P. A.; Goodwin, S. P. (2005). "On the massive stellar population of the super star cluster Westerlund�1". Astronomy and Astrophysics 434 (3): 949. Bibcode:2005A&A...434..949C. doi:10.1051/0004-6361:20042413. 
  5. ^ Fukui, Y.; Ohama, A.; Hanaoka, N.; Furukawa, N.; Torii, K.; Dawson, J. R.; Mizuno, N.; Hasegawa, K.; Fukuda, T.; Soga, S.; Moribe, N.; Kuroda, Y.; Hayakawa, T.; Kawamura, A.; Kuwahara, T.; Yamamoto, H.; Okuda, T.; Onishi, T.; Maezawa, H.; Mizuno, A. (2014). "Molecular Clouds Toward the Super Star Cluster Ngc 3603; Possible Evidence for a Cloud-Cloud Collision in Triggering the Cluster Formation". The Astrophysical Journal 780: 36. Bibcode:2014ApJ...780...36F. doi:10.1088/0004-637X/780/1/36. 
  6. ^ Massey, Philip; Hunter, Deidre A. (1998). "Star Formation in R136: A Cluster of O3 Stars Revealed by Hubble Space Telescope Spectroscopy". The Astrophysical Journal 493: 180. Bibcode:1998ApJ...493..180M. doi:10.1086/305126. 
  7. ^ Hunter, Deidre A.; O'Connell, Robert W.; Gallagher, J. S.; Smecker-Hane, Tammy A. (2000). "The Star Clusters in the Starburst Irregular Galaxy NGC 1569". The Astronomical Journal 120 (5): 2383. Bibcode:2000AJ....120.2383H. doi:10.1086/316810. 

External links[edit]