Untangling the merger history of massive black holes with LISA
نویسنده
چکیده
Binary black hole coalescences emit gravitational waves that will be measurable by the space-based detector LISA to large redshifts. This suggests that LISA may be able to observe black holes grow and evolve as the universe evolves, mapping the distribution of black hole masses as a function of redshift. An immediate difficulty with this idea is that LISA measures certain redshifted combinations of masses with good accuracy: if a system has some mass parameter m, then LISA measures (1+z)m. This mass-redshift degeneracy makes it difficult to follow the mass evolution. In many cases, LISA will also measure the luminosity distance D of a coalescence accurately. Since cosmological parameters (particularly the mean density, the cosmological constant, and the Hubble constant) are now known with moderate precision, we can obtain z from D and break the degeneracy. This makes it possible to untangle the mass and redshift and to study the mass and merger history of black holes. Mapping the black hole mass distribution could open a window onto an early epoch of structure formation.
منابع مشابه
Formation of massive stars and black holes in self-gravitating AGN discs, and gravitational waves in LISA band
We propose a scenario in which massive stars form at the outer edges of an AGN accretion disc. We analyze the dynamics of a disc forming around a supermassive black hole, in which the angular momentum is transported by turbulence induced by the disc’s self-gravity. We find that once the surface density of the disc exceeds a critical value, the disc fragments into dense clumps. We argue that the...
متن کاملThe Merger History of Supermassive Black Holes in Galaxies
The ubiquity of supermassive black holes (SMBHs) at the centers of nearby luminous galaxies can arise from the multiple mergers experienced by dark matter halos in hierarchical structure formation models, even if only a small fraction of these galaxies harbor SMBHs at high redshifts. We illustrate this possibility using cosmological Monte Carlo simulations of the merger history of dark matter h...
متن کاملLISA Observations of Supermassive Black Hole Growth
Based on a high resolution cosmological n-body simulation, we track the hierarchical growth of black holes in galaxy clusters from z = 20 to z = 0. We present a census of black holes as function of redshift and will determine their mass assembly history under a variety of assumptions regarding the importance of gas accretion in black hole growth, from early supercritical Eddington accretion to ...
متن کاملAdvanced localization of massive black hole coalescences with LISA
The coalescence of massive black holes is one of the primary sources of gravitational waves (GWs) for LISA. Measurements of the GWs can localize the source on the sky to an ellipse with a major axis of a few tens of arcminutes to a few degrees, depending on source redshift, and a minor axis which is 2–4 times smaller. The distance (and thus an approximate redshift) can be determined to better t...
متن کامل