Related papers: Primordial molecular clouds
The development of primordial inhomogeneities into the non-linear regime and the formation of the first bound objects mark the transition from a simple cooling universe -- described by just a few parameters -- to a very messy hot one -- the…
Numerical simulations suggest that the first galaxies are formed in protogalactic halos with virial temperatures >= 10^4 K. It is likely that such halos are polluted with trace amounts of metals produced by the first generation of stars.…
We investigate the possible impact of diffusion on the abundance of helium and other primordial elements during formation of the first structures in the early Universe. We consider the primary collapse of a perturbation and subsequent…
Observational studies reveal that complex organic molecules (COMs) can be found in various objects associated with different star formation stages. The identification of COMs in prestellar cores, i.e., cold environments in which thermally…
The majority of hydrogen in the interstellar medium (ISM) is in atomic form. The transition from atoms to molecules and, in particular, the formation of the H$_2$ molecule, is a key step in cosmic structure formation en route to stars.…
The Primordial Black Holes (PBHs) are gradually involved into consideration as the phenomenon having reliable basis. We discuss here the possibility of their agglomeration into clusters that may have several prominent observable features.…
We have carried out a systematic search for the molecular ion CO+ in a sample of 8 protoplanetary and planetary nebulae in order to determine the origin of the unexpectedly strong HCO+ emission previously detected in these sources. An…
Molecular hydrogen (H$_2$) formation and dissociation are key processes that drive the gas lifecycle in galaxies. Using the SImulating the LifeCycle of Molecular Clouds (SILCC) zoom-in simulation suite, we explore the utility of future…
The elegance of inflationary cosmology and cosmological perturbation theory ends with the formation of the first stars and galaxies, the initial sources of light that launched the phenomenologically rich process of cosmic reionization. Here…
The difference in density profiles of the contributions from different density peaks to dark matter halos results in certain expectations about the Milky Way's stellar halo. We cut our simulated halo stars into two populations: those…
Over the last two decades, realistic studies have often concluded that the first bound objects to form can be very small, much smaller than a solar mass. After recombination, the Jeans mass drops rapidly to the order of a Giant Molecular…
The formation of quasar black holes during the hydrodynamic collapse of protogalactic gas clouds is discussed. The dissipational collapse and long- term dynamical evolution of these systems is analysed using three-dimensional numerical…
Primordial nucleosynthesis is rightly hailed as one of the great successes of the standard cosmological model. Here we consider the initial forging of elements in the recently proposed Rh = ct universe, a cosmology that demands linear…
Comets have similar compositions to interstellar medium ices, suggesting at least some of their molecules maybe inherited from an earlier stage of evolution. To investigate the degree to which this might have occurred we compare the…
We present 3D "zoom-in" simulations of the formation of two molecular clouds out of the galactic interstellar medium. We model the clouds - identified from the SILCC simulations - with a resolution of up to 0.06 pc using adaptive mesh…
The first stars to form in protogalaxies must have primordial chemical composition. We refer to a protogalaxy that is forming stars of primordial composition, or very low metallicity ($Z\le 0.01 Z_{\odot}$), as ``Primordial Proto-Galaxy''…
The laboratory work presented here, simulates the chemistry on icy dust grains as typical for the 'CO freeze-out stage' in dark molecular clouds. It differs from previous studies in that solid-state hydrogenation and vacuum…
It is currently assumed that infrared dark clouds (IRDCs) represent the earliest evolutionary stages of high-mass stars ($>$ 8 M$_{\odot}$). Submillimeter and millimeter-wave studies performed over the past 15 years show that IRDCs possess…
Carbon monoxide (CO) is the primary tracer for interstellar clouds where stars form, yet CO has never been detected in galaxies with an Oxygen abundance relative to Hydrogen less than 20% of solar, even though such low metallicity galaxies…
Using a new physical model for star formation (Padoan 1995) we have tested the possibility that globular clusters (GCs) are formed from primordial mass fluctuations, whose mass scale ($10^8$ - $10^9$ M$_{\odot}$) is selected out of a CDM…