Research
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2024.11.29
The research of dark matter halos with galaxy-galaxy lensing method
In the standard LambdaCDM cosmological framework, cosmic structures grow through a hierarchical process. As fundamental building blocks of the dark matter universe, halos are believed to follow a self-similar structure distribution. Thus, we could stacking the weak lensing signal of multiple halos with the galaxy-galaxy lensing (gglens) method, and obtain the average profile of halos. (A.) With...
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2024.11.28
Water chemistry of the Enceladus ocean and the habitability of icy moons [EN]
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...
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2024.11.27
Five parameters are all you need [EN]
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...
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2024.11.22
On the Role of Structural Bimodality on Galaxy Quenching in Local Universe [EN]
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 ...
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2024.11.21
A new picture of active galactic nuclei disks [EN]
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...
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