Related papers: The Habitable Epoch of the Early Universe
Early JWST observations have revealed a high-redshift universe more vibrant than predicted by canonical galaxy-formation models within $\Lambda$CDM, showing an excess of ultraviolet(UV)-bright, massive, and morphologically mature galaxies.…
The Cosmic Microwave Background (CMB) is a relict of the early universe. Its perfect 2.725K blackbody spectrum demonstrates that the universe underwent a hot, ionized early phase; its anisotropy (about 80 \mu K rms) provides strong evidence…
The formation of the first galaxies at redshifts z~10-15 signaled the transition from the simple initial state of the universe to one of ever increasing complexity. We here review recent progress in understanding their assembly process with…
Solar X-ray and UV radiation (0.1-320 nm) received at Earth's surface is an important aspect of the circumstances under which life formed on Earth. The quantity that is received depends on two main variables: the emission of radiation by…
The first structures in the Universe formed at z>7, at higher redshift than all currently known galaxies. Since GRBs are brighter than other cosmological sources at high redshift and exhibit simple power-law afterglow spectra that is ideal…
The formation of the first generations of stars at redshifts z > 15-20 signaled the transition from the simple initial state of the universe to one of increasing complexity. We here review recent progress in understanding the assembly…
The first galaxies that formed at a redshift ~20-30 emitted continuum photons with energies between the Lyman-alpha and Lyman limit wavelengths of hydrogen, to which the neutral universe was transparent except at the Lyman-series…
During its first ~100,000 years, the universe was a fully ionized plasma with a tight coupling by Thompson scattering between the photons and matter. The trade--off between gravitational collapse and photon pressure causes acoustic…
From hydro-gravitational cosmology, hydrogen-helium gas planets fragmented at the plasma to gas transition 300,000 years after the big bang in million-star-mass clumps. Stars may form in the clumps by mergers of the planets to make globular…
The discovery of the cosmic microwave background (CMB) in 1964 by Penzias and Wilson led to the establishment of the hot big-bang cosmological model some ten years later. Discoveries made in 1998 may ultimately have as profound an effect on…
It is attractive to suppose for several astrophysical reasons that the universe has close to the critical density in light (~30 eV) neutrinos which decay radiatively with a lifetime of ~10^{23} sec. In such a cosmology the universe is…
During the post-main sequence phase of stellar evolution the orbital distance of the habitable zone, which allows for liquid surface water on terrestrial planets, moves out past the system's original frost line, providing an opportunity for…
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…
The H atoms inside minihalos (i.e. halos with virial temperatures T_vir < 10^4 K, in the mass range roughly from 10^4 M_sun to 10^8 M_sun) during the cosmic dark ages in a LCDM universe produce a redshifted background of…
Cosmic objects with magnetic fields (quasars, radiogalaxies) are observed at redshifts $z\geq 7$ (Wang et al., 2021, Fan et al., 2023, Yang et al., 2024) and more (for instance, for $z = 10.073\pm 0.002$, Goulding et al., 2023) indicates…
Hydrogravitional-dynamics (HGD) cosmology of Gibson/Schild 1996 predicts proto-globular-star-cluster PGC clumps of Earth-mass planets fragmented from plasma at ~0.3 Myr. Protogalaxies retained the ~0.03 Myr baryonic density existing at the…
The presence of a liquid solvent is widely regarded as an essential prerequisite for habitability. We investigate the conditions under which worlds outside the habitable zones of stars are capable of supporting liquid solvents on their…
Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the…
Hydrogen cyanide (HCN) is crucial for the RNA World hypothesis, forming biomolecules essential for early life. Life likely emerged around 4 billion years ago during the early Archean Eon, a period on Earth with a fainter sun, frequent…
We present results of cosmological N-body hydrodynamic chemistry simulations of primordial structure growth and evolution in a scenario with warm dark matter (WDM) having a mass of 3 keV (thermal relic) and compare with a model consisting…