RCW 38 is a star-forming region in the southern constellation of Vela (known as the Sails). It includes an embedded HII region and a super star cluster. This region is located at a distance of approximately 5,500light-years from the Sun.

This is the youngest super star cluster in the Milky Way galaxy, with age estimates ranging from 0.1 to 1.0 Myr. It has around 10,000 member stars. The cluster member stars are still enshrouded within the dark cloud in which they were born. The star cluster is surrounded by clouds of brightly glowing gas and includes many protostars. It is therefore classified as an infrared cluster. Observations by the Chandra X-ray Observatory have revealed more than 800 X-ray emitting young stellar objects in the cluster. 139 infrared sources have been identified as variable, of which 47% are candidate young stellar objects. Jets emerging from young protostars drive further star formation in the surrounding cloud.

The cluster includes about 20 massive O-type stars concentrated in a volume a few parsecs across. The latter stars are having a dissipative effect on the surrounding molecular gas. Five bow shocks have been identified coming from these objects, driven by strong stellar winds. When these massive stars die, likely before the dispersal of the cluster, they will explode as supernovae. It is hypothesized that these O-type stars were formed by a collision of two molecular clouds. The primary cloud has a mass of 3×104M☉, while the secondary cloud has 2×103M☉.

In the infrared, the brightest star in this region is designated IRS 2. This is a binary star system consisting of two spectral type O5.5 stars. It is located at the heart of the cluster, and appears to lie at the center of the H II region. The second brightest source is a dust ridge designated IRS 1, positioned about 0.1pc to the west of IRS 2. Both sources are surrounded by a dust-free cavity about 0.1pc across.

RCW 38 includes Gum 22, Gum 23, and Gum 24.[clarification needed]

Gallery

  • The location of RCW 38 (circled in red)
  • An X-ray view of the dense central star cluster
  • Central part of RCW 38, showing some of the brown dwarf candidates detected within the cluster
  • The wider region surrounding RCW 38

Further reading

  • Pandey, Paarmita; etal. (November 2024). . The Astrophysical Journal. 976 (1). id. 98. arXiv:. Bibcode:. doi:.
  • Ge, Ting-Ting; etal. (May 2024). . Monthly Notices of the Royal Astronomical Society. 530 (1): 1144–1150. arXiv:. Bibcode:. doi:.
  • Fukushima, Aoto; etal. (February 2023). "Suzaku and Chandra study of diffuse X-ray emission from the massive star-forming region RCW 38". Publications of the Astronomical Society of Japan. 75 (1): 187–198. Bibcode:. doi:.
  • Izumi, Natsuko; etal. (February 2021). "Observations of the [C I] (3P1-3P0) emission toward the massive star-forming region RCW 38: Further evidence for highly-clumped density distribution of the molecular gas". Publications of the Astronomical Society of Japan. 73 (1): 174–196. arXiv:. Bibcode:. doi:.
  • Mužić, Koraljka; etal. (November 2017). . Monthly Notices of the Royal Astronomical Society. 471 (3): 3699–3712. arXiv:. Bibcode:. doi:.
  • Kaneda, H.; etal. (August 2013). "Large-scale mapping of the massive star-forming region RCW38 in the [CII] and PAH emission". Astronomy & Astrophysics. 556. id. A92. arXiv:. Bibcode:. doi:.
  • Bik, A.; etal. (April 2010). "Sequential Star Formation in RCW 34: A Spectroscopic Census of the Stellar Content of High-Mass Star-Forming Regions". The Astrophysical Journal. 713 (2): 883–899. arXiv:. Bibcode:. doi:.
  • DeRose, K. L.; etal. (July 2009). "A Very Large Telescope/NACO Study of Star Formation in the Massive Embedded Cluster RCW 38". The Astronomical Journal. 138 (1): 33–45. arXiv:. Bibcode:. doi:.
  • Wolk, S. J.; etal. (December 2008). "The Embedded Massive Star Forming Region RCW 38". In Reipurth, Bo (ed.). Handbook of Star Forming Regions, volume II. The Southern Sky ASP Monograph Publications. Vol.5. p.124. arXiv:. Bibcode:.
  • Gyulbudaghian, A. L.; May, J. (January 2008). "Investigation of the conspicuous infrared star cluster and star-forming region "RCW 38 IR Cluster"". Astrophysics. 51 (1): 18–28. Bibcode:. doi:. hdl:.
  • Wolk, Scott J.; etal. (December 2002). "Discovery of Nonthermal X-Ray Emission from the Embedded Massive Star-forming Region RCW 38". The Astrophysical Journal. 580 (2): L161–L165. Bibcode:. doi:.
  • Smith, Craig H.; etal. (February 1999). . Monthly Notices of the Royal Astronomical Society. 303 (2): 367–379. Bibcode:. doi:.
  • Ligori, S.; etal. (1994). "Near infrared imaging of the southern HII region RCW 38". Memorie della Societa Astronomica Italiana. 65: 815–818. Bibcode:.
  • Mizutani, K.; etal. (October 1987). . Monthly Notices of the Royal Astronomical Society. 228 (3): 721–727. Bibcode:. doi:.
  • Takami, H.; etal. (August 1987). "Far-infrared O III fine-structure lines and ionization structure of RCW 38". Publications of the Astronomical Society of the Pacific. 99: 832–835. Bibcode:. doi:.
  • Muzzio, J. C.; Celotti de Frecha, M. B. (October 1979). (PDF). Monthly Notices of the Royal Astronomical Society. 189 (2): 159–162. Bibcode:. doi:.

External links