We present Hubble Space Telescope (HST) Near-Infrared Camera and Multiobject Spectrometer (NICMOS) observations as evidence that continuous star formation has created much of the central stellar cusp of the Galaxy. The data are the deepest ever obtained for a Galactic Center (GC) population, being >50% complete for mF205W< 19.3, or initial stellar masses &2 M⊙. We use Geneva and Padova stellar evolution models to produce synthetic luminosity functions for burst and continuous star formation scenarios, finding that the observations are fit best by continuous star formation at a rate that is consistent with the recent star formation activity that produced the three massive young clusters in the central 50 pc. Further, it is not possible to fit the observations with ancient burst models, such as would be appropriate for an old population like that in Baade’s Window or NGC6528. (Refer to PDF file for exact formulas).

Publication Date



Also archived in: arXiv:astro-ph/0309757 v1 28 Sep 2003 Support for this work was provided by NASA through grant number GO-07364.01-96A and AR-08751.02-A from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. Mark Morris is supported by NSF through AST9988397.ISSN:1538-4357 Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.

Document Type


Department, Program, or Center

School of Physics and Astronomy (COS)


RIT – Main Campus