The AIMSS Project I: bridging the star cluster, galaxy divide

• Autores: Norris, Mark A.; Kannappan, Sheila J.; Forbes, Duncan A.; Romanowsky, Aaron J.; Brodie, Jean P.; Faifer, Favio Raúl; Huxor, Avon; Maraston, Claudia; Moffett, Amanda J.; Penny, Samantha J.; Pota, Vincenzo; Smith Castelli, Analia Viviana; Strader, Jay; Bradley, David; Eckert, Kathleen D.; Fohring, Dora; McBride, JoEllen; David V. Stark; Vaduvescu, Ovidiu
• Año de publicación: 2014
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Galaxies; Stars; Globular clusters; Formation of galaxies; Evolution of galaxies; Massive stars
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

We describe the structural and kinematic properties of the first compact stellar systems discovered by the AIMSS project. These spectroscopically confirmed objects have sizes (∼6 < Re [pc] < 500) and masses (∼2×106 < M∗/M < 6×109 ) spanning the range of massive globular clusters (GCs), ultra compact dwarfs (UCDs) and compact elliptical galaxies (cEs), completely filling the gap between star clusters and galaxies. Several objects are close analogues to the prototypical cE, M32. These objects, which are more massive than previously discovered UCDs of the same size, further call into question the existence of a tight mass–size trend for compact stellar systems, while simultaneously strengthening the case for a universal “zone of avoidance” for dynamically hot stellar systems in the mass–size plane. Overall, we argue that there are two classes of compact stellar systems: 1) massive star clusters and 2) a population closely related to galaxies. Our data provide indications for a further division of the galaxy-type UCD/cE population into two groups, one population that we associate with objects formed by the stripping of nucleated dwarf galaxies, and a second population that formed through the stripping of bulged galaxies or are lower-mass analogues of classical ellipticals. We find compact stellar systems around galaxies in low to high density environments, demonstrating that the physical processes responsible for forming them do not only operate in the densest clusters.
Fil: Norris, Mark A. . Max Planck Institut für Astronomie; Alemania
Fil: Kannappan, Sheila J. . University Of North Carolina; Estados Unidos
Fil: Forbes, Duncan A. . Swinburne University. Centre for Astrophysics & Supercomputing; Australia
Fil: Romanowsky, Aaron J. . University of California; Estados Unidos
Fil: Brodie, Jean P.. University of California; Estados Unidos
Fil: Faifer, Favio Raúl . Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Astrofísica de La Plata; Argentina
Fil: Huxor, Avon . Universit¨at Heidelberg. Zentrum f¨ur Astronomie. Astronomisches Rechen-Institut; Alemania
Fil: Maraston, Claudia . Institute of Cosmology and Gravitation. Dennis Sciama Building; Estados Unidos
Fil: Moffett, Amanda J. . University Of North Carolina; Estados Unidos
Fil: Penny, Samantha J. . Monash University. School of Physics; Australia
Fil: Pota, Vincenzo . Swinburne University. Centre for Astrophysics & Supercomputing; Australia
Fil: Smith Castelli, Analia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Astrofísica de La Plata; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina
Fil: Strader, Jay . Michigan State University; Estados Unidos
Fil: Bradley, David . University Of North Carolina; Estados Unidos
Fil: Eckert, Kathleen D. . University Of North Carolina; Estados Unidos
Fil: Fohring, Dora . Isaac Newton Group of Telescopes; España
Fil: McBride, JoEllen . University Of North Carolina; Estados Unidos
Fil: David V. Stark. University Of North Carolina; Estados Unidos
Fil: Vaduvescu, Ovidiu . Isaac Newton Group of Telescopes; España