A5085924289- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Advanced SAR Imaging Techniques
- Radio Astronomy Observations and Technology
Shanghai Astronomical Observatory
2014-2021
Chinese Academy of Sciences
2016
Netherlands Institute for Radio Astronomy
2014
Abstract We present photometric selection of type 1 quasars in the ≈5.3 deg 2 XMM-Large Scale Structure survey field with machine learning. constructed our training and blind-test samples using spectroscopically identified Sloan Digital Sky Survey quasars, galaxies, stars. utilized XGBoost learning method to select a total 1591 quasars. assessed classification performance based on sample, outcome was favorable, demonstrating high reliability (≈99.9%) good completeness (≈87.5%). used estimate...
Abstract Narrow‐line Seyfert 1 galaxies are thought to be young AGNs with relatively small black hole masses and high accretion rates. Radio‐loud narrow‐line (RLNLS1s) very special, because some of them show blazar‐like characteristics, while others resemble compact steep‐spectrum sources. Relativistic jets were shown exist in a few RLNLS1s based on VLBI observations confirmed by the gamma‐ray flaring them. These properties may possibly contrary typical radio‐loud AGNs, light low black‐hole...
Abstract We present near-infrared spectroscopy of 10 weak emission-line quasars (WLQs) at redshifts z ∼ 2, obtained with the Palomar 200 inch Hale Telescope. WLQs are an exceptional population type 1 that exhibit or no broad emission lines in ultraviolet (e.g., C iv λ 1549 line), and they display remarkable X-ray properties. derive H β -based single-epoch virial black hole masses (median value 1.7 × 9 M ⊙ ) Eddington ratios 0.5) for our sources. confirm previous finding WLQ lines, as a major...