13 papers
Supermassive stars with embedded stellar black hole cores: dense assembling star clusters as faint multiple Little Red Dot systems
Antti Rantala
Numerical simulations have established that star clusters with densities comparable to the high redshift (-) James Webb Space Telescope (JWST) proto globular clusters may…
Elusive Plunges and Heavy Intermediate-mass-ratio Inspirals from Single and Binary Supermassive Black Holes
Lazaros Souvaitzis, Antti Rantala, Thorsten Naab
The most massive galaxies in the Universe also host the largest supermassive black holes (SMBHs), with masses of and above. During their hierarchical a…
FROST-CLUSTERS -- III. Metallicity-dependent intermediate mass black hole formation by runaway collisions in dense star clusters
Antti Rantala, Thorsten Naab, Natalia Lahén +4
We explore the formation of intermediate mass black holes (IMBHs), potential seeds for supermassive black holes (SMBHs), via runaway stellar collisions for a wide range of star clu…
Rapid sinking and efficient mergers of supermassive black holes in compact high-redshift galaxies
Atte Keitaanranta, Peter H. Johansson, Alexander Rawlings +5
We present a cosmological zoom-in simulation targeting the high redshift compact progenitor phase of massive galaxies, with the most massive galaxy reaching a stellar mass of $M_{\…
Caught in the act: detections of recoiling supermassive black holes from simulations
Alexander Rawlings, Peter H. Johansson, Thorsten Naab +3
We study the detectability of supermassive black holes (SMBHs) with masses of displaced by gravitational wave recoil kicks $(v_{\rm ki…
Mergers all the way down: stellar collisions and kinematics of a dense hierarchically forming massive star cluster in a dwarf starburst
Natalia Lahén, Thorsten Naab, Antti Rantala +1
Recent observations indicate that the progenitors of globular clusters (GCs) at high redshifts had high average stellar surface densities above $10^5\, \mathrm{M}_\odot\, \mathrm{p…