Related papers: Caught in the Act?
Stellar-mass black holes (BHs), with masses comparable to stars, are a major constituent of our Milky Way galaxy. This chapter describes the landscape of challenging, and long-sought efforts to identify these objects in the Galaxy. The…
According to the Big Bang Theory as we go back in time the Universe becomes progressively hotter and denser. This leads us to believe that the early Universe was filled with hot plasma of elementary particles. Among many questions…
There is compelling evidence that supermassive black holes exist. Yet the origin of these objects, or their seeds, is still unknown. We discuss several plausible scenarios for forming the seeds of supermassive black holes. These include the…
Stars in galaxies form when baryons radiatively cool down and fall into gravitational wells whose mass is dominated by dark matter. Eventually, star formation quenches as gas is depleted and/or perturbed by feedback processes, no longer…
Understanding how supermassive black holes (SMBHs) form in the early universe is one of the most challenging problems in astrophysics. Their high abundance in the first billion years, as observed by the James Webb Space Telescope, hints…
The first massive astrophysical black holes likely formed at high redshifts (z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations. These black holes grow by mergers and gas accretion, evolve into the population of bright…
Observational work conducted over the last few decades indicates that all massive galaxies have supermassive black holes at their centres. Although the luminosities and brightness fluctuations of quasars in the early Universe suggest that…
The cosmic history of star formation is briefly reviewed, starting with the Milky Way and then discussing observations relevant to the closed box and hierarchical build-up models. Observations of local star formation are reviewed for…
Black holes with hundreds to thousands of solar masses are more massive than can be formed from a single star in the current universe, yet the best candidates for these objects are not located in gas-rich environments where gradual…
We describe the model of protogalaxy formation around the cluster of primordial black holes with a minimum extension of standard cosmological model. Namely, it is supposed, that a mass fraction of the universe ~10^-3 is composed of the…
We present a model for the formation of massive ($M > 10 M_\odot$) stars through accretion-induced collisions in the cores of embedded dense stellar clusters. This model circumvents the problem of accreting onto a star whose luminosity is…
According to the current understanding of cosmic structure formation, the precursors of the most massive structures in the Universe began to form shortly after the Big Bang, in regions corresponding to the largest fluctuations in the cosmic…
Rapid infall of gas in the nuclei of galaxies could lead to the formation of black holes by direct collapse, without first forming stars. Black holes formed in this way would have initial masses of a few solar masses, but would be embedded…
We use high resolution simulations to study the formation and distribution of galaxies within a cluster which forms hierarchically. We follow both dark matter and baryonic gas which is subject to thermal pressure, shocks and radiative…
Properties of normal galactic star formation, including the density dependence, threshold density, turbulent scaling relations, and clustering properties, are applied to the formation of galactic bulges. One important difference is that the…
The QCD phase transition in the early universe may provide primordial black hole nuclei for globular clusters. We consider the accretion and star formation that follow, once 1000 solar mass nuclei have formed. When such a nucleus has…
We consider the cosmological model in which a part of the Universe \Omega_h\sim 10^-5 is in the form of primordial black holes with mass \sim 10^5M_\odot. These primordial black holes would be centers for growing protogalaxies which…
It is believed that there may have been a large number of black holes formed in the very early universe. These would have quantised masses. A charged ``elementary black hole'' (with the minimum possible mass) can capture electrons, protons…
Collapsed objects have definitely been observed: some are stellar-mass objects, the endpoint of massive stars; others, millions of times more massive, have been discovered in the cores of most galaxies. Their formation poses some…
How stars are born from clouds of gas is a rich physics problem whose solution will inform our understanding of not just stars but also planets, galaxies, and the universe itself. Star formation is stupendously inefficient. Take the Milky…