Department of Astronomy

Prof. Lugger has been a member of the IU Astronomy faculty since 1984.  She uses the Hubble Space Telescope and the Chandra X-ray Observatory to study X-ray emitting binary stars in globular star clusters. Globular clusters occupy a special place in astrophysics as they provide a local laboratory for studying fundamental issues in stellar dynamics and stellar evolution. These studies have included the optical identification of Chandra X-ray sources in the nearby core-collapsed globular clusters NGC 6397 and NGC 6752 and the non-core-collapsed clusters 47 Tuc and M4. The counterparts that have been found include cataclysmic variables, chromospherically active binaries, and millisecond pulsars. Studies of the spatial distribution of these sources are used to study the effects of dynamical interactions on the production and evolution of these sources and to investigate the dynamical state of the clusters.

Exotica in the globular cluster M4, studied with Chandra, HST and the VLA, Lugger, Phyllis M., Cohn, Haldan N., Heinke, Craig O., Zhao, Jiaqi, Zhao, Yue, Anderson, Jay 2023, MNRAS, 524, 2088. 

A deep search for faint Chandra X-ray sources, radio sources and optical counterparts in NGC 6752, Cohn, Haldan N., Lugger, Phyllis M., Zhao, Yue, and 6 more 2021, MNRAS, 508, 2823.

A deep Chandra survey for faint X-ray sources in the Galactic globular cluster M30, and Searches of optical and radio counterparts, Zhao, Yue, Heinke, Craig O., Cohn, Haldan N., Lugger, Phyllis M., and 10 more 2020, MNRAS, 499, 3338.

The X-ray emissivity of low-density stellar populations, Heinke, C. O., Ivanov, M. G., Koch, E. W., Andrews, R., Chomiuk, L., Cohn, H. N., Crothers, S. de Boer, T., Ivanova, N., Kong, A. K. H., Leigh, N. W. C., Lugger, P. M., and 8 more 2020, MNRAS, 492, 5684.

Identifications of faint Chandra sources in the globular cluster M3, Zhao, Y., Heinke, C. O., Cohn, H. N., Lugger, P. M., Cool, A. M. 2019, MNRAS, 483, 4560.

The radius of the quiescent neutron star in the globular cluster M13, Shaw, A. W., Heinke, C. O., Steiner, A. W., Campana, S., Cohn, H. N., Ho, W. C. G., Lugger, P. M., Servillat, M. 2018, MNRAS, 476, 4713.

New cataclysmic variables and other exotic binaries in the globular cluster 47 Tucanae*, Rivera Sandoval, L. E., van den Berg, M., Heinke, C. O., Cohn, H. N., Lugger, P. M., Anderson, J., Cool, A. M., Edmonds, P. D., Wijnands, R., Ivanova, N., Grindlay, J. E. 2018, MNRAS, 475, 4841.

Identification of Faint Chandra X-Ray Sources in the Core-collapsed Globular Cluster NGC 6752, Lugger, P. M., Cohn, H., Cool, A. M., Heinke, C. O., Anderson, J. 2017, ApJ, 841, 53.

View the complete list from the Astrophysics Data System

• A100: The Solar System
• A105: Stars and Galaxies