相关论文: Protostellar Feedback and Final Mass of the Second…
First-generation (Population III) stars in the universe play an important role inearly enrichment of heavy elements in galaxies and intergalactic medium and thus affect the history of galaxies. The physical and chemical properties of…
We carry out radiation hydrodynamical simulations of the formation of massive stars in the super-Eddington regime including both their radiative feedback and protostellar outflows. The calculations start from a prestellar core of dusty gas…
The key question about early protostellar evolution is how matter is accreted from the large-scale molecular cloud, through the circumstellar disk onto the central star. A sample of 20 Class 0 and I protostars has been observed in continuum…
The formation, evolution and death of massive stars release large quantities of energy and momentum into the gas surrounding the sites of star formation. This process, generically termed 'feedback', inhibits further star formation either by…
A promising formation channel of SMBHs at redshift 6 is the so-called DC model, which posits that a massive seed BH forms through gravitational collapse of a $\sim 10^5~M_\odot$ SMS. We study the evolution of such a SMS growing by rapid…
Supermassive stars (SMSs) forming via very rapid mass accretion (Mdot >~ 0.1 Msun/yr) could be precursors of supermassive black holes observed beyond redshift of about 6. Extending our previous work, we here study the evolution of…
The formation of supermassive stars is believed to be an essential intermediate step for the formation of the massive black hole seeds that become the supermassive black holes powering the quasars observed in the early Universe. Numerical…
The observational consequences of the merger scenario for massive star formation are explored and contrasted with the gradual accumulation of mass by accretion. Protostellar mergers may produce high luminosity infrared flares lasting years…
Identifying the processes that determine strength, duration and variability of protostellar mass growth is a fundamental ingredient of any theory of star formation. I discuss protostellar mass accretion rates dM/dt from numerical models…
The formation of low-mass stars in molecular clouds involves accretion disks and jets, which are of broad astrophysical interest. Accreting stars represent the closest examples of these phenomena. Star and planet formation are also…
We report on simulations of the formation of the first stars in the Universe, where we identify regions of hot atomic gas (fH2 < 10-6) at densities above 10-14 g/cc, heated to temperatures ranging between 3000 and 8000 K. Within this…
The formation of massive stars may take place at relatively low accretion rates over a long period of time if the accretion can continue past the onset of core hydrogen ignition. The accretion may continue despite the formation of an…
The earliest phases of star formation are characterised by intense mass accretion from the circumstellar disk to the central star. One group of young stellar objects, the FU Orionis-type stars exhibit accretion rate peaks accompanied by…
I review recent progress in understanding the formation of the first stars and quasars. The initial conditions for their emergence are given by the now firmly established model of cosmological structure formation. Numerical simulations of…
From studying the cosmic microwave background, we know our Universe started out very simple. It was by and large homogeneous and isotropic, with small fluctuations that can be described by linear perturbation theory. In stark contrast, the…
We present the first results of a study of the expected properties of the first stellar generations in the Universe. In particular, we consider and discuss a series of properties that, on the basis of the emission from associated HII…
Supermassive stars (SMSs) with masses of $M_\ast \simeq 10^4$--$10^5~{\rm M_\odot}$ are invoked as possible seeds of high-redshift supermassive black holes, but it remains under debate whether their protostar indeed acquires sufficient mass…
We present a sample of nine high resolution cosmological simulations in the mass range of M_vir=7x10^11-4x10^12 M_sun starting from LambdaCDM initial conditions. Our simulations include primordial radiative cooling, photoionization, star…
Star formation efficiency controlled by the protostellar outflow in a single cloud core is investigated by three-dimensional resistive MHD simulations. Starting from the prestellar cloud core, the star formation process is calculated until…
It has been proposed that some hot molecular cores (HMCs) harbor a young embedded massive star, which heats an infalling envelope and accretes mass at a rate high enough to ``choke off'' an incipient HII region. This class of HMCs would…