Research
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2024.09.13
Identifying the Galactic Substructures in 5D Space Using All-sky RR Lyrae Stars in Gaia DR3
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...
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2024.09.12
Supermassive black holes in the Universe
Supermassive black holes are extensively discussed in this talk: 1) cosmic evolution of SMBHs; 2) masses and spins; 3) SMBH binaries and nano-Hz gravitational waves; 4) Satellite black holes around SMBH; 5) new opportunity of SMBH research in the JWST and VLTI era.BIOJianming Wang is astrophysics professor in IHEP. He got PhD in USTC in 1995 and originally from National University of Defense Te...
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2024.09.12
Tensions on small scales: Too many galaxy-galaxy strong lenses in galaxy clusters?
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...
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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
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...
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2024.09.05
Deep Synoptic Array and FRB
Fast radio bursts (FRBs) are typically milli-second-duration luminous radio transients whose source remain debatable. Caltech/ OVRO's Deep Synoptic Array-110 (DSA-110) is the only radio interferometer designed specifically for FRB searching and localization. By mid-2023, DSA-110 has doubled the number of localized FRBs. First, I will highlight the high-resolution burst morphology of a sample...
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