Deep IR adaptive optics imaging of the core of M71

• Main Author: Ruberg, Andres
• Format: Others
• Language: English
• Published: University of British Columbia 2009
• Online Access: http://hdl.handle.net/2429/5347

Data collected in H and K bands from Gemini North observatory using the NIRI/ALTAIR adaptive optics (AO) system, have been used to draw a number of new conclusions about the globular cit ster M71. K band obser vations were made in 2 epochs, separated by a 1.81 year baseline, allowing for the separation of field stars from cluster stars based on proper motion. A color-magnitude diagram (CMD) made using only cluster stars agrees well with current models. A stellar density profile was also constructed and appears to flatten at small radii, suggesting that a multimass King profile does describe the cluster quite accurately, a result contrary to that found in other work. Most significantly, the distance to M71 was calculated using the measured velocity dispersion compared to the radial dispersion measured for giant stars. The distance measured was 3.36 ± 0.71 kpc.