GCIRS 13E

Last updated
GCIRS 13E
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Sagittarius
Right ascension 17h 45m 39.73s [1]
Declination −29° 00 29.7 [1]
Distance 26,000  ly
(8,000 [2]   pc)
Other designations
WR 101f
Database references
SIMBAD data

GCIRS 13E is an infrared and radio object near the galactic centre. It is believed to be a cluster of hot massive stars, possibly containing an intermediate-mass black hole (IMBH) at its centre.

GCIRS 13E was first identified as GCIRS 13, which was later resolved into two components GCIRS13E and W. [3] GCIRS 13E was initially modelled as a single object, possibly a binary system. [4] It was even classified as a Wolf-Rayet star because of its strong emission line spectrum, and named WR 101f. [5] It was then resolved into seven Wolf-Rayet and class O stars. [6] The highest-resolution infrared imaging and spectroscopy can now identify 19 objects in GCIRS 13E, of which 15 are dense gaseous regions. The remaining four objects are stars: WN8 and WC9 Wolf-Rayet stars; an OB supergiant; and a K3 giant. [2]

The motions of the members of GCIRS 13E appear to indicate a much higher mass than can be accounted for by the visible objects. It has been proposed that there may be an intermediate-mass black hole with a mass of about 1,300  M at its centre. There are a number of problems with this theory. [7] However, the true nature of the cluster remains unknown. [2]

GCIRS 13E is a small cluster dominated by a few massive stars. It is thought that massive stars cannot form so close to a supermassive black hole and since such massive stars have a short lifespan it is thought that GCIRS 13E must have migrated inward toward the central black hole within the past 10 million years, probably from about 60 light-years further out than its current orbit. The stars are possibly the remains of a globular cluster where a middleweight black hole could develop through runaway star collisions. [7] GCIRS 13E could also be a dark star cluster which forms in the inner Galaxy if the evaporation rate of stars from the cluster is faster due to a strong tidal field than the depletion of the black hole content though ejections. [8]

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Sagittarius A* cluster

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References

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  6. Maillard, J. P.; Paumard, T.; Stolovy, S. R.; Rigaut, F. (2004). "The nature of the Galactic Center source IRS 13 revealed by high spatial resolution in the infrared". Astronomy and Astrophysics. 423: 155–167. arXiv: astro-ph/0404450 . Bibcode:2004A&A...423..155M. doi:10.1051/0004-6361:20034147. S2CID   15806243.
  7. 1 2 Schoedel, R.; A. Eckart; C. Iserlohe; R. Genzel; T. Ott (2005). "A Black Hole in the Galactic Center Complex IRS 13E?". Astrophys. J. 625 (2): L111–L114. arXiv: astro-ph/0504474 . Bibcode:2005ApJ...625L.111S. doi:10.1086/431307. S2CID   10250848.
  8. Banerjee, S.; P. Kroupa (2011). "A New Type of Compact Stellar Population: Dark Star Clusters". Astrophys. J. Lett. 741 (1): L12–L19. arXiv: 1110.4103 . Bibcode:2011ApJ...741L..12B. doi: 10.1088/2041-8205/741/1/L12 .