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2024.06.25

Probing Cosmic Reionization with JWST/NIRSpec Ly Observations

<p>The JWST is ushering in a new era of observing galaxies in the reionization era, providing us new insights into this last major phase transition of the Universe. The Ly-alpha emission from young star forming galaxies, which is sensitive to the presence of neutral HI along the line of sight, has been used as an important probe of the reionization process. JWST/NIRSpec offers spectroscopic capabi...</p>

2024.06.24

Photoionization models with turbulent structures

<p>Turbulence features ubiquitously in the interstellar medium, especially in the high-redshift Universe. Photoionization models with turbulent ISM density fields can predict nebular emission lines more realistically than the former uniform density/pressure photoionization models. In this talk, we will briefly introduce a turbulent photoionization model grid created by the cutting-edge 3D Monte Ca...</p>

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>