首页

2024.09.20

Unveiling the 70-year mystery of the nature of carbon-deficient red giants

<p>Weak G-band stars, or carbon-deficient red giants (CDGs), characterised by weak or absent G-band absorption of the CH molecule driven by low carbon abundances, have remained mysterious for decades. Here, we present a significant increase in the known CDG population identified through systematic spectroscopic surveys. This expanded sample confirms their rarity (&lt;1% of giants). Combining asterose...</p>

2024.09.13

Identifying the Galactic Substructures in 5D Space Using All-sky RR Lyrae Stars in Gaia DR3

<p>Motivated by the vast gap between photometric and spectroscopic data volumes, there is great potential in using 5D kinematic information to identify and study substructures of the Milky Way. We identify substructures in the Galactic halo using 46,575 RR Lyrae stars (RRLs) from Gaia DR3 with the photometric metallicities and distances newly estimated by Li et al. (2023). Assuming a Gaussian prio...</p>

2024.06.28

Gaia + Bayesian Power: A Deep Dive into Open Cluster Mass Function & Binaries

<p>Open clusters (OCs) are cradles of stars and building blocks of galaxies, offering insights into how stars and galaxies form. It is essential to precisely measure the parameters of OCs, such as age, metallicity, distance, dust extinction, stellar mass function (MF), and binary fraction. I propose a novel Bayesian framework that can identify OC candidates and simultaneously estimate these parame...</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>

2024.06.14

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>

2024.06.07

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>

2024.05.31

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>

2024.05.24

A Euclid View of the Intracluster Light in the Perseus Cluster

<p>I will present new state-of-the art observations of the Perseus Cluster taken as part of the Euclid Early Release Observations. &nbsp;This data allows us, for the first time, to characterize the intracluster light (ICL) and intracluster globular clusters (ICGCs) in Perseus out to 600 kpc from the BCG. &nbsp;We find that within 500kpc of the BCG, there are 70,000 globular clusters and that the ICL account...</p>

2024.05.17

Portable Fantacies: How to Work with Android-like Devices

<p>Over the past few years, the computing capability of portable devices equipped with ARM processors has expanded exponentially. Yet, despite their growing power, the prevalent Android-like operating systems often confine users to a &#39;walled garden,&#39; restricting direct interaction with the core Linux functionalities. In this presentation, we will explore the transformative potential of Termux and ...</p>

2024.05.10

Biases and uncertainties in quantifying morphology of galaxies at high redshifts with JWST

<p>Observations of high-redshift galaxies with unprecedented detail have now been rendered possible with JWST. However, accurately quantifying their morphology remains uncertain due to potential biases and uncertainties. To address this issue, I used a sample of 1816 nearby DESI galaxies to compute artificial images of galaxies of the same mass located at high redshifts and observed at rest-frame ...</p>