科学研究
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2023.10.24
An Overview of Stellar Evolution and Pollution in AGN Disk (SEPAD) and their Implication on the Stellar Dynamics in the Galactic Center and around other Supermassive Black Holes
Extended regions of accretion disks around supermassive black holes in bright AGNs are prone to gravitational instability, star formation and stellar dynamical evolution with feedback to the disks' structure. Spectroscopic data provide vital clues on the stellar and residual black hole populations. Their dynamical interaction with each other, their natal disks, and other massive companions in a...
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2023.10.20
TRANSforM: stellar parameters estimated from LAMOST DR10 M dwarfs
The accurate determination of stellar parameters in M-type stars holds significant importance in various astronomical studies. In our study, we employed a transfer learning method coupled with PHOENIX synthetic spectra to estimate fundamental atmospheric parameters (Teff, log g, [M/H], [α/M]) and radial velocities (RV) for an extensive dataset encompassing 581,778 M dwarfs obtained from the Lo...
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2023.10.19
Radio observations of fast variations in microquasars
Microquasars are the compact objects generally including accreting black holes which produce relativitic jets. The physical mechanisms of jet launching, collimation, and acceleration are poorly understood. Microquasars show strong variability in multi-wavelength observations. In X-rays, the sources show the fast variation features up to millisecond time scales, with the prominant quasiperiodic ...
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2023.10.17
existing tensions in ΛCDM model
The concordance or standard Λ Cold Dark Matter (ΛCDM) model is a well-defined, predictive and simple cosmological model. A number of challenges of the standard ΛCDM model have been emerging during the past few years, which has been summarized by recent reviews.In this talk, I will give a brief introduction to several existing signals in cosmological and astrophysical data that appear to be i...
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2023.10.13
Multiband gravitatioanl wave observations of stellar binary black holes
The ground-based gravitational wave (GW) observatories discover a population of merging stellar binary black holes (BBHs), which are promising targets for multiband observations by the low-, middle-, and high-frequency GW detectors. We investigate the multiband GW detections of BBHs and demonstrate the advantages of such observations in improving the localization and parameter estimates of the ...
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