Open AccessYoung stars in the Galactic Centre: a potential intermediate‐mass star origin
Author(s) -
Dray L. M.,
King A. R.,
Davies M. B.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10841.x
Subject(s) - physics , astrophysics , stars , astronomy , initial mass function , supermassive black hole , stellar dynamics , star cluster , population , star formation , galactic center , galaxy , demography , sociology
There has been recent speculation that the cores of intermediate‐mass stars stripped of their envelopes by tidal interaction with the supermassive black hole in the Galactic Centre could form a population observationally similar to the so‐called Sgr A* cluster or ‘S’ stars, which have close eccentric orbits around the hole. We model the evolution of such stars, and show that the more luminous end of the population may indeed appear similar to young B stars within the observational limits of the Galactic Centre region. Whether some or all of these cluster stars can be accounted for in this manner depends strongly on the assumed initial mass function (IMF) of the loss cone stars and the scattering rate. If most of the observed stars are in fact scattered from the Galactic Centre inner cusp region itself then the population of ∼20 to current observational limits may be reproduced. However, this only works if the local relaxation time is small and relies on the cusp stars themselves being young, i.e. it is dependent on some star formation being possible in the central few parsecs. Conversely, we obtain a possible constraint on the tidal stripping rate of ‘normal’ IMF stars if there are not to be red stars visible in the Sgr A* cluster.