Enceladus, a small icy satellite of Saturn, was found to have a subsurface water ocean and evidence of ongoing hydrothermal activity in the seafloor. The ocean water, sampled via a plume, was inferred to contain substantial levels of inorganic and organic carbon as well as ammonia. However, there are very few constraints on the availability of other bio-essential nutrients, including phosphorus...
The standard cosmological model (ΛCDM) relies on six free parameters, five of which have direct cosmological origins, while the sixth, the optical depth (τ), is an ad hoc parameter used to model the scattering effects experienced by cosmic microwave background (CMB) photons. CMB photons decoupled from the primordial plasma at z ~ 1100 when neutral hydrogen formed, reducing the abundance of fr...
Observations have shown that the termination of the star-forming activity in galaxies (quenching of star formation) is closely related to the structure of the galaxies, in the sense that passive galaxies tend to possess more compact structure. The surface mass density in the core region effectively describes the compactness of galaxies, and therefore have served to be one of the most sensitive ...
The current model of accretion disks, that of Shakura and Sunyaev (1973) asserts that such disks are geometrically thin, and are prone to a number of instabilities. One such instability is that of fragmentation due to self-gravity at radii larger than a few hundred black hole gravitational radii, which would limit the mass accretion rate to be well below that observed to occur. Recent GIZMO (La...
The variations in the size of galaxies, and consequently, the formation of Low Surface Brighntess Galaxies (LSBGs) could be followed from one of two different effects: variations in the spin parameter of the halo (λ) or variations in the density of dark matter halos (McGaugh 2021). We test both scenarios by employing a simulated sample of galaxies drawn from the TNG100 run of the IllustrisTNG ...