CCD photometry of globular cluster core structure. I. NGC 6388, NGC 6624, and M15: one flat core and two cusps

Journal Article · Tue Sep 01 04:00:00 EDT 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165566· OSTI ID:5776533

Lugger, P M; Cohn, H; Grindlay, J E; Bailyn, C D; Hertz, P

The first results of a major survey of globular cluster core structure are reported. Surface brightness profiles for three clusters are presented: one with a normal flat core profile (NGC 6388), and two with central cusps (NGC 6624 and M15). The profiles are fitted with both seeing-convolved King models and seeing-convolved power laws. A King model provides a reasonable fit to the entire profile of NGC 6388, but there are no acceptable King profiles for NGC 6624 and M15. For these two clusters, a seeing-convolved power law provides a good fit to the inner part of the profile, while a King model gives a good fit to the outer part of the profile. The interpretation of the measured power-law slopes of the central surface brightness cusps of NGC 6624 and M15 are discussed in terms of models for core collapse in a multicomponent cluster. 58 references.

• Research Organization: Indiana Univ., Bloomington; Harvard Univ., Cambridge, MA; E.O. Hulburt Center for Space Research, Washington, DC
• OSTI ID: 5776533
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 320; ISSN ASJOA
• Country of Publication: United States
• Language: English

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