首页

2024.12.25

Studying cosmology and astrophysics by the synergy of RSD and kSZ effects

<p>As one main target of cosmological surveys, the galaxy peculiar velocity field encodes information about the cosmic structure growth history and significantly contributes to the study of dark energy and dark matter. Its detection is typically made by the redshift space distortion (RSD) and kinetic Sunyaev-Zel’dovich (kSZ) effects in cosmology. In this talk, I will present high signal-to-noise ...</p>

2024.12.20

TOI-880 Has An Aligned, Coplanar Multi-planet System [EN]

<p>We present the stellar obliquity measurement of TOI-880 c (TOI-880.01) using Rossiter-McLaughlin (RM) observations obtained with the Keck Planet Finder (KPF). TOI-880 is a compact multi-transiting system with 3 transiting planets. Our independent analysis revealed that the host star is a K-type star. Planet b (TOI-880.02) has a radius of 2.23 ± 0.10R⊕ and an orbital period of 2.6 days; planet ...</p>

2024.12.11

Discussion on DESI Y1 results [EN]

<p>Since DESI has released their cosmological constraints from BAO and Full-shape Analysis with DESI Y1 data in April and November respectively, in the seminar next week, Siyi Zhao and Wenshuo Xu (both are 4th year graduate students) are going to briefly present and discuss DESI Y1 results, including a general introduction to DESI project, methodology and their key cosmological constraints. Welcom...</p>

2024.12.13

A potential mass-gap black hole in a wide binary with a circular orbit

<p>The mass distribution of black holes identified through X-ray emission suggests a paucity of black holes in the mass range of 3 to 5 solar masses. Modified theories have been devised to explain this mass gap, and it is suggested that natal kicks during a supernova explosion can more easily disrupt binaries with lower-mass black holes. Although recent Laser Interferometer Gravitational-Wave Obse...</p>

2024.12.12

Dark Matter under the Gravitational Lens [EN]

<p>Dark Matter (DM) is the clearest sign that the Standard Model of particle physics is incomplete. &nbsp;A determination of the DM particle mass will rule out entire classes of hypothetical extensions to the Standard Model, thus pointing the correct path towards New Physics. &nbsp;In this talk, I describe how gravitational lensing can differentiate between the two top contenders for DM: ultra-massive (WIMP...</p>

2024.12.06

Investigating the Squeezed Limit of Primordial Non-Gaussianity: New Constraints from CMB Anisotropies [EN]

<p>The Primordial non-Gaussianity provides fundamental insights into the early Universe and constitutes a crucial area of research in contemporary cosmology. Recently, we extended the cosmological analysis presented in Ibitoye2024 beyond the intergalactic medium (IGM) to investigate the primordial non-Gaussianity parameter (f^0_NL) in the squeezed limit, using the auto- and cross-power spectra of ...</p>

2024.12.04

Imaging Giant Planet Formation [EN]

<p>The new generation of infrared high-contrast imagers and sub-mm interferometer has been revolutionising our view of planet formation for the last decade. Protoplanetary discs have now been imaged at a high level of detail, revealing a wealth of structures including cavities, annular gaps, spiral arms, shadows and asymmetries. In order to connect these structures to forming planets and provide t...</p>

2024.12.04

Emulating Extended Lyman Alpha Halos Around Star-Forming Galaxies [EN]

<p>The detection of the extended Lyman-alpha emission (or Lyman-alpha halos) around star-forming galaxies opens a new window for probing the circum-galactic medium (CGM) at high redshifts. With IFU observations (e.g., through MUSE), we are already capable of measuring the spatially resolved Lya spectra around individual galaxies, revealing a diverse population of the Lya emission. However, interpr...</p>

2024.11.27

Five parameters are all you need [EN]

<p>The standard cosmological model (ΛCDM) relies on six free parameters, five of which have direct cosmological origins, while the sixth, the optical depth (τ), is an ad hoc parameter used to model the scattering effects experienced by cosmic microwave background (CMB) photons. CMB photons decoupled from the primordial plasma at z ~ 1100 when neutral hydrogen formed, reducing the abundance of fr...</p>

2024.11.29

The research of dark matter halos with galaxy-galaxy lensing method

<p>In the standard LambdaCDM cosmological framework, cosmic structures grow through a hierarchical process. As fundamental building blocks of the dark matter universe, halos are believed to follow a self-similar structure distribution. Thus, we could stacking the weak lensing signal of multiple halos with the galaxy-galaxy lensing (gglens) method, and obtain the average profile of halos. (A.) With...</p>