Our Dynamic Universe: Smadar Naoz’s Group

Exploring various dynamical interactions in our Universe

During these past two years, Bao-Minh Hoang graduated and joined Kall Morris Inc. as an Orbital Trajectory Specialist. Sanaea Rose graduated and accepted the prestigious CIERA fellowship at Northwestern. Furthermore, the group welcomed Dr. Erez Michaely as a joint Bhaumik postdoc fellow. Moreover, Dr. Santiago Torres joined ISTA as a Marie Curie fellow, and Dr. Brenna Mockler became a Carnegie fellow. 

It's raining black holes and stars ... Hallelujah! Almost every galaxy has a supermassive black hole (SMBH) residing at its heart, the Milky Way included. Further, the hierarchical nature of structure formation implies that SMBH binaries are common in our universe. In these extreme environments, stellar-mass BHs and stars in the dense environment surrounding SMBHs undergo weak gravitational scattering. In a series of papers, we demonstrated that these scatterings combined with torques from an SMBH companion result in an influx of BHs and stars toward one of the SMBH pairs. 

Stellar, white dwarfs, and neutron star mergers and collisions occur in various environments, from the galactic field to the center of galaxies. We demonstrated that it could lead to the formation of larger stars and black holes, as well as gravitational wave events. Tertiary companions (bound or interloper), such as an SMBH or a star, often assist with these mergers and collisions.

The earliest star formation, as gas advected away, is potentially detectable by JWST. In the early universe, different patches of the universe had various advecting speeds, leading to star-forming objects with peculiar properties, such as dark matter-less star clusters or high-spinning, extremely luminous dwarf galaxies. In a long-term collaboration called the supersonic project, our group is leading the study of these objects. 

Bizarre extrasolar systems  (in comparison to our own) seem to be common in our galaxy. For example, some have short-period planets (days to a few hours orbit), eccentric planets, warped debris disks, and more. Our group seeks these bizarre systems and analyzes and predicts their properties and frequency in the galaxy.