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2024.11.21

On the Formation, Evolution and the Environment of Low Surface Brightness Galaxies [EN]

<p>The variations in the size of galaxies, and consequently, the formation of Low Surface Brighntess Galaxies (LSBGs) could be followed from one of two different effects: variations in the spin parameter of the halo (λ) or variations in the density of dark matter halos (McGaugh 2021). We test both scenarios by employing a simulated sample of galaxies drawn from the TNG100 run of the IllustrisTNG ...</p>

2024.11.20

[PDS seminar] The instability mechanism of compact multiplanet systems [EN]

<p>Numerical integrations of Kepler-like tightly packed planetary systems show that they are chaotic, with fairly short Lyapunov times, but that they can be stable against planet-planet or planet-star collisions for billions of years. Recent work by Petit et al. showed that this behavior was due to the overlap of three-body mean motion resonances. Caleb Lammers, Sam Hadden and I recently showed th...</p>

2024.10.22

Mapping the 3D Universe: From the Past to the Future, Bridging Theories and Observations

<p>This collaborative talk introduces the recent work in COSMO-3D group at EPFL’s Laboratory of Astrophysics (LASTRO). Jiaxi Yu (PhD student) will begin with a historical review of cosmology. The Universe started from a Big Bang, followed by inflation. The emission of the first light of the Universe, cosmic microwave background (CMB), happened in an opaque and dark era of the Universe afterwards....</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>

2024.09.05

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>

2024.08.26

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>

2024.08.19

Beyond Summary Statistics: Leveraging Generative Models for Field-Level Weak Lensing Analysis

<p>Current and future weak lensing surveys contain significant information about our universe. However, their optimal cosmological analysis is challenging, with traditional analyses often resulting in information loss due to reliance on summary statistics like two-point functions. While deep learning methods offer promise in capturing the complex non-linear features of these cosmological fields, t...</p>

2024.08.23

Role of dark matter halo angular momentum distribution on bar formation, evolution and dynamical friction

<p>In this study, we investigated the role of the inner halo&#39;s angular momentum distribution on bar formation and evolution processes. We performed a series of high-resolution N-body experiments with Milky Way-type disk galaxies. These models were initiated with similar disks but with varying inner halo angular momentum in the surrounding dark matter halo. The bar triggered earlier in the model wi...</p>

2024.08.16

Unveiling the Milky Way Dust Extinction Curve in 3D

<p>Despite the vital importance of interstellar dust to many areas of astronomy, its composition and properties are highly uncertain. The dust extinction curve (the relation of extinction vs. wavelength) depends on both the grain-size distribution and the chemistry of the dust, and is therefore a probe of dust properties. The dust extinction curve is typically characterized by R(V) ≡ A(V)/E(B − ...</p>