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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>

2024.12.19

Magnetospheric Radio Emissions: from Jupiter to exoplanets and stars [EN]

<p>Jupiter&#39;s radio emissions have been intensively studied since their discovery some 70 years ago. Space missions have extended these studies to radio emissions from all planetary magnetospheres in the solar system. Main emission characteristics have been determined (source location, directivity, power, polarization, etc.) and their microscopic generation process elucidated (primarily the electro...</p>

2024.09.04

Comprehensive population synthesis predictions for massive binary stars in the Small Magellanic Cloud

<p>The past and ongoing gravitational wave detections have fostered a wide interest in understanding the formation of binary black holes (BBHs). Several formation scenarios have been proposed, including the evolution of isolated massive binaries. While most of the observed merging black holes are at cosmological distances, and thus likely at low metallicity, the Small Magellanic Cloud (SMC) provid...</p>

2024.09.12

Tensions on small scales: Too many galaxy-galaxy strong lenses in galaxy clusters?

<p>In the standard cosmological model, the matter content of the Universe is dominated by cold dark matter (CDM), collisionless particles that interact with ordinary matter (baryons) only through gravity. Gravitationally bound dark-matter halos form hierarchically, with the most massive systems growing through mergers of smaller ones. As structure assembles in this fashion, large dark-matter halos...</p>

2024.09.03

The role of mixing, mass-loss and rotation in stellar evolution

<p>Despite the efforts made in recent decades to obtain more realistic stellar models, considerable uncertainties still remain due to our incomplete knowledge of some complex physical processes that occur within them, such as accretion, convection, mass loss, rotation, to name a few of them. Modeling these processes still relies on empirical calibrations and this has a significant impact on theore...</p>

2024.09.05

A precise measurement of the supermassive black hole mass in the galaxy NGC 383 using molecular gas kinematics down to the circumnuclear disc

<p>I will present a measurement of the supermassive black hole (SMBH) mass in NGC 383, a nearby lenticular galaxy hosting a low-power radio jet, based on ALMA observations of the CO(2-1) emission line with an angular resolution of 0.′′050 × 0.′′024 (≈ 16 pc × 8 pc). These observations spatially resolve the nuclear molecular gas disc down to ≈ 41300 Schwarzschild radii and the SMBH sphere of...</p>

2024.09.05

Deep Synoptic Array and FRB

<p>Fast radio bursts (FRBs) are typically milli-second-duration luminous radio transients whose source remain debatable. &nbsp;Caltech/ OVRO&#39;s Deep Synoptic Array-110 (DSA-110) is the only radio interferometer designed specifically for FRB searching and localization. &nbsp;By mid-2023, DSA-110 has doubled the number of localized FRBs. &nbsp;First, I will highlight the high-resolution burst morphology of a sample...</p>

2024.08.29

Exploring Stellar Astrophysics and Star-Planet Interactions Through Observational Studies

<p>Photometric and spectroscopic observations of individual stars, binaries, and group of stars in coeval populations offer valuable insights into various stellar characteristics, such as chemical abundance, radial velocity, multiplicity, mass, distance, and age. The chemical abundances provide critical information about the internal physics of stars, the interactions between planets and their hos...</p>

2024.08.26

The stellar environment's influence on protoplanetary discs and planet formation

<p>Stars born in dense clusters often form binary systems, surrounded by circumbinary discs of gas and dust. Misalignments between these discs and the binary orbit are common during stellar evolution, driven by dissipation. My research, utilizing 3D hydrodynamical simulations, focuses on the evolution of highly misaligned circumbinary discs. I demonstrate that polar-aligned circumbinary discs are ...</p>

2024.10.10

Probing the spacetime variation of the fine-structure constant using emission-line galaxies

<p>The Standard Model of particle physics assumes that fundamental physical constants, including the fine-structure constant alpha, are universal and constant. On the other hand, modern theories beyond the Standard Model predict or even require the variation of the fundamental constants. Recently, we developed a new method to probe the variation in alpha using narrow and strong [O III] emitting ga...</p>