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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>

2024.05.14

Gravitational radiation from oscillations of ultracompact stars

<p>By analytically solving the Teukolsky gravitational&nbsp;wave equation for the spacetime of an ultracompact star of constant density, we derive exact and simple formulae that completely describe&nbsp;weakly damped oscillations trapped inside such stars. No similar&nbsp;complete analytic solution was known before, despite several attempts&nbsp;to find it. Our solution is cast in terms of the quasi normal modes&nbsp;of o...</p>

2024.05.08

Dark Matter Halo and its Structure, Assembly, and Clustering

<p>Dark matter halos are the major composition of the cosmic structures in our Universe and, therefore, play a central role in studying galaxies and cosmology. In cosmological N-body simulations, dark matter halos can be investigated from three perspectives: their structures, assembly histories, and spatial clustering. This talk will focus on our recent work on this topic. In the first part, I wil...</p>

2024.04.26

Research on the Structure, Chemistry and Kinematics of the Milky Way Based on the Large-scale Sky Surveys

<p>With the advent of massive large-scale sky surveys, such as, the SDSS for photometry, the LAMOST for spectroscopy, and Gaia for astrometry, we are entering a golden era of Galactic studies and precise multi-dimensional information (e.g., 3D position, 3D velocity, chemical element abundance ratios, and stellar age) is now available for some huge samples of stars in the Milky Way. Leveraging thes...</p>

2024.04.23

Gas Accretion and AGN Feedback in the Late Stage Evolution of Massive Ellipticals

<p>Observations indicate that massive elliptical galaxies in the contemporary universe exhibit both low star formation rates and low AGN luminosity. This raises a question: Given continuous gas accretion, how do these massive ellipticals maintain their quiescent state? SMBH feedback is a widely accepted solution to this issue, yet the mechanisms how it prevents gas accretion and subsequent star fo...</p>

2024.04.24

Evolutionary Mechanisms in nearby galaxies: Insights from Statistical Analysis of Observations and Cosmological Simulations

<p>Galaxies are complex systems influenced by numerous factors. Despite extensive research, we cannot yet explain the diverse properties of nearby galaxies. Gas accretion, environments, galaxy merging, and supermassive black hole (SMBH) feedback play pivotal roles in galaxy evolution. In this talk, I will present an overview of my recent and current research. My work entails a comprehensive compar...</p>

2024.04.16

Modelling sub-millimetre emission from the cold circumgalactic medium around high redshift galaxies

<p>TBC</p>

2024.04.16

The 4MOST instrument and upcoming spectroscopic surveys

<p>The 4MOST consortium has been selected by the European Southern Observatory (ESO) to provide the ESO community with a fibre-fed spectroscopic survey facility on the VISTA telescope with a large enough field-of-view to survey a large frac­tion of the southern sky in a few years. The facility will be able to simultaneously obtain spectra of ~2400 objects distributed over an hexagonal field-of-vie...</p>

2024.04.15

X-ray emissions from the large scale structure of the Universe with an eROSITA focus

<p>I will present the maps of the large scale structure at soft X-ray wavelength obtained by eROSITA. I will discuss how the observed emission unravels the properties of the circum-galactic medium of our Milky-Way and nearby galaxies.Then I discuss what astrophysical and cosmological information is contained in the map subtended by X-ray detected clusters and Active galactic nuclei</p>

2024.04.19

SgrA∗ spin and mass estimates through the detection of an extremely large mass-ratio inspiral

<p>Estimating the spin of SgrA∗ is one of the current challenges we face in understanding the center of our Galaxy. In the present work, we show that detecting the gravitational waves (GWs) emitted by a brown dwarf inspiraling around SgrA∗ will allow us to measure the mass and the spin of SgrA∗ with unprecedented accuracy. Such systems are known as extremely large mass-ratio inspirals (XMRIs) a...</p>