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2024.06.21

Granulation in Red Supergiants: The Scaling Relations

<p>Granulations are structures characterized by convection cells reaching the stellar surface and are well-known through observations of the Sun. However, similar granulation structures may also be present on the surfaces of the largest and brightest cool stars in the Universe—the red supergiants (RSGs)—potentially serving as the primary mechanism of their irregular light variations. As predicte...</p>

2024.06.18

The strong-lensing revolution in the JWST-Rubin-Roman era: from resolving the Hubble tension to constraining baryonic feedback

<p>Despite the remarkable success of the Lambda Cold Dark Matter (LCDM) cosmological model, several challenges have recently emerged. One of the most prominent is the “Hubble tension”: the Hubble expansion rate (H_0) measured using the Cepheid-calibrated distance ladder of type Ia supernovae and the value extrapolated from the cosmic microwave background using LCDM disagree by 5 standard deviati...</p>

2024.06.14

Heating the Super-hot Corona in Solar Active Regions: Insights from RMHD Simulations

<p>What physical mechanisms heat the outer solar or stellar atmosphere to million-kelvin temperatures is a fundamental but long-standing open question. In particular, the solar corona in active-region cores contains an even hotter component reaching 10 MK, manifesting as persistent coronal loops in extreme ultraviolet and soft X-ray images, which imposes a stringent energy budget. Here, we present...</p>

2024.07.03

Exoplanet atmospheres with high-resolution spectroscopy: chemistry, isotopes, and dynamics

<p>Exoplanet atmospheres with imprints from their history open an important avenue to trace the origin and evolution of planets. With high-dispersion spectroscopy, we can resolve atomic and molecular spectral features into unique forests of lines that serve as fingerprints for identifying different species and probing structures and dynamics of exoplanet atmospheres. I will talk about high-resolut...</p>

2024.06.11

Perturbative Modeling of Galaxy Large-scale Structure

<p>Current and future galaxy surveys such as HETDEX, DESI, Euclid, PFS, and SPHEREx aim to address fundamental questions in cosmology. For all these galaxy surveys, galaxy clustering is the primary observable, so modeling the nonlinearities in galaxy clustering is essential to decipher the survey data. Perturbative modeling offers an efficient, flexible, and robust method to achieve this.In this t...</p>

2024.06.05

Cosmological formation of globular clusters

<p>Cosmological formation of globular cluster</p>

2024.06.07

Glitching pulsars as sources of transient gravitational waves

<p>The spin of neutron stars can be timed with exquisite precision and are seen observationally as pulsars. They are observed to spin-down steadily over long periods but once in a while, they can undergo a rapid and sudden increase in their spin, which is known as a glitch. For some cases, the glitch is followed by a post-glitch recovery. There are several models that predict the emission of conti...</p>

2024.06.04

Spatially Resolved Star Formation of Galaxies at z ~ 1 - 3 from HST and JWST Observations

<p>Investigating spatially resolved properties of galaxies offers important constraints on the mechanisms by which galaxies form stars and grow in stellar mass. The James Webb Space Telescope (JWST) not only facilitates a systematic exploration of high redshift galaxies, but also enables a detailed study of the rest-frame mid-infrared (mid-IR) and the optical emission lines of galaxies at intermed...</p>

2024.05.28

Mathematica code for calculating CMB anisotropy

<p>The Planck mission measures the cosmic microwave background (CMB) with unprecedentedly precision. The angular spectra extracted from Planck&#39;s CMB measurements can be used to test gravitational theories and cosmological models. This is done by comparing the observational results with theoretical predictions that can be calculated by solving together the Boltzmann equation governing the evolution...</p>

2024.05.31

Formation of satellite systems around Jupiter and Saturn

<p>Satellite systems around Jupiter and Saturn have different characteristics. The Saturnian system is dominated by a giant moon, Titan, which holds over 95% of the total mass of Saturnian moons. On the other hand, the Jovian system has four large moons in a compact orbital area, and inner three, Io, Europa and Ganymede, are known to be in resonant orbits. Previous studies have shown that the spec...</p>