Related papers: Binary Disruption and Ejected Stars from Hierarchi…
The present dynamical configuration of planets in binary star systems may not reflect their formation process since the binary orbit may have changed in the past after the planet formation process was completed. An observed binary system…
We examine the conditions under which binary and multiple stars may form out of turbulent molecular cloud cores using high resolution 3-D, adaptive mesh refinement (AMR) hydrodynamics (Truelove et al., 1997, 1998; Klein, 1999). We argue…
Observations from optical to centimeter wavelengths have demonstrated that multiple systems of two or more bodies is the norm at all stellar evolutionary stages. Multiple systems are widely agreed to result from the collapse and…
Observations and theory suggest that star clusters can form in a subvirial (cool) state and are highly substructured. Such initial conditions have been proposed to explain the level of mass segregation in clusters through dynamics, and have…
A significant fraction of, and possibly all, stars form in binary or multiple systems. For Solar-mass stars in the Galactic field, the distribution of orbital separations is log-normal over seven orders of magnitude, from $10^{-2} - 10^5$…
We study the shape and evolution of the star formation main sequence in three independently developed semi-analytic models of galaxy formation. We focus, in particular, on the characterization of the model galaxies that are significantly…
GW231123 is the most massive binary black hole (BBH) merger detected to date by the LIGO-Virgo-KAGRA collaboration. With at least one black hole (BH) in the upper-mass gap and both BHs exhibiting high spins ($\chi_{1,2} \gtrsim 0.8$), this…
We simulate a cluster of 144179 stars including 13107 primordial hard binaries (10% of the total number of single stars and binary centers of mass), using direct integration of the equations of motion of all stars and binaries and…
How stellar clusters disrupt, and over what timescales, is intimately linked with how they form. Here, we review the theory and observations of cluster disruption, both the suggested initial rapid dissolution phase (infant mortality) and…
This paper uses statistical and $N$-body methods to explore a new mechanism to form binary stars with extremely large separations ($> 0.1\,{\rm pc}$), whose origin is poorly understood. Here, ultra-wide binaries arise via chance entrapment…
Massive stars (> 8 $M_\odot$) are known to have high degrees of multiplicity, e.g., with about 60% in triples or higher-order multiples. Such high levels of multiplicity may arise during formation (primary multiplicity) or through dynamical…
Most, if not all, stars in the field are born in binary configurations or higher multiplicity systems. In dense stellar environment such as the Galactic Center (GC), many stars are expected to be in binary configurations as well. These…
Classical Cepheid variable stars provide a unique probe to binary evolution in intermediate-mass stars over the course of several tens to hundreds of Myr. We studied the binary and multiple properties of Cepheids, assuming that all mid-B…
The evolution of a protostellar binary system is investigated while it is embedded in its parent molecular cloud core and acted upon by gas drag due to dynamical friction. Approximate analytical results are obtained for the energy and…
We study the compact binary population in star clusters, focusing on binaries containing black holes, using a self-consistent Monte Carlo treatment of dynamics and full stellar evolution. We find that the black holes experience strong mass…
Observations of young star-forming regions suggest that star clusters are born completely mass segregated. These initial conditions are, however, gradually lost as the star cluster evolves dynamically. For star clusters with single stars…
We investigate the evolution of mass segregation in initially sub-structured young embedded star clusters with two different background potentials mimicking the gas. Our clusters are initially in virial or sub-virial global states and have…
This is the first paper about the fragmentation and mass outflow in the molecular cloud by using three-dimensional MHD nested-grid simulations. The binary star formation process is studied paying particular attention to the fragmentation of…
The interaction of binary black hole mergers with their environments can be studied using numerical relativity simulations. These start only a short finite time before merger, at which point appropriate initial conditions must be imposed. A…
We explore a newly proposed channel to create binary black holes of stellar origin. This scenario applies to massive, tight binaries where mixing induced by rotation and tides transports the products of hydrogen burning throughout the…