Kavli Affiliate: Lijing Shao | Summary:The detection of a pulsar closely orbiting our Galaxy’s supermassive black hole – Sagittarius~A* – is one of the ultimate prizes in pulsar astrophysics. The relativistic effects expected in such a system could far exceed those currently observable in compact binaries such as double neutron stars and pulsar white dwarfs. […]
Kavli Affiliate: Kejia Lee | Summary:Pulsar timing arrays (PTAs) are ensembles of millisecond pulsars observed for years to decades. The primary goal of PTAs is to study gravitational-wave astronomy at nanohertz frequencies, with secondary goals of undertaking other fundamental tests of physics and astronomy. Recently, compelling evidence has emerged in established PTA experiments for the […]
Kavli Affiliate: Huawei Zhang | Summary:The epoch of the Gaia-Sausage-Enceladus (GSE) merger, the last major merger experienced by the Milky Way, is crucial for reconstructing the Galaxy’s evolutionary history. This event dynamically heated the disk, scattering some stars into the halo and producing the so-called Splash. Yet the observed age distribution of the Splash is […]
Kavli Affiliate: Kejia Lee | Summary:FRB~20240114A is an extremely active repeating fast radio burst for which plasma lensing has been proposed to explain its burst-rate variations, spectral evolution, and apparently “carbon-copy” burst pairs. Using FAST data and publicly available Parkes observations, we test this interpretation with a one-dimensional Gaussian plasma-lens model. Although the burst-rate enhancements […]
Kavli Affiliate: Yingjie Peng | Summary:Feedback from active galactic nuclei (AGN) is now recognized as a key component of galaxy formation models. It plays a central role in regulating the growth and quenching of galaxies in the center of groups. However, the impact of AGN feedback from central galaxies on satellite galaxies remains largely unexplored. […]
Kavli Affiliate: Kejia Lee | Summary:We implemented a data acquisition system for 21 CentiMeter Array (21CMA), enabling baseband observations targeting pulsars and fast radio bursts. Based on the Radio Frequency System-on-Chip (RFSoC) platform, the new backend is capable of instantaneously covering the effective bandwidth from 50 to 350 MHz, with multi-board synchronization achieved at the […]
Kavli Affiliate: Claudio Ricci | Summary:The accretion-ejection mechanism in Active Galactic Nuclei (AGN) remains a central open problem in astrophysics, tied to the role of AGN feedback in galaxy formation and evolution. Radio-quiet AGN dominate the observed AGN population. Lacking luminous jets, their radio emission traces a rich set of processes spanning the host galaxy […]
Kavli Affiliate: Xian Chen| Summary: Quasi-periodic eruptions (QPEs) are repeated X-ray bursts originating in galactic nuclei. Of the many proposed models, the favored model is the disk-collision model in which a stellar mass orbiter collides with a disk formed from a tidal disruption event, generating flares twice per orbit. In this model QPEs are tracers […]
Kavli Affiliate: Xian Chen| Summary: Quasi-periodic eruptions (QPEs) are repeated X-ray bursts originating in galactic nuclei. Of the many proposed models, the favored model is the disk-collision model in which a stellar mass orbiter collides with a disk formed from a tidal disruption event, generating flares twice per orbit. In this model QPEs are tracers […]
Kavli Affiliate: Feng Long| Summary: We present JWST/MIRI spectroscopy of 14 disks in the older (~5-10 Myr) Upper Scorpius (USco) association and use slab of gas in local thermal equilibrium to infer basic gas properties. We find that half of these disks are molecular rich, with detections of H$_2$O, CO$_2$, HCN, C$_2$H$_2$, and H$_2$, while […]