近期特別學術演講

Professor Yue Shen (Department of Astronomy, University of Illinois at Urbana-Champaign)

"The final parsec: time-domain exploration of the inner regions of quasars"

時間/地點: 2018-12-21 15:00 [S4-1013]

摘要:

The spatially-unresolved sub-parsec region of quasars (rapidly accreting supermassive black holes) is a dynamic environment where the most important processes related to BH accretion and feedback are taking place. Studying this region observationally, however, requires somewhat different approaches that are not hurdled by the spatial resolution requirement. A hallmark characteristic of quasars is their ubiquitous variability over a wide range of wavelengths and timescales from intra-day to decades, which provides unique and critical constraints on the structure, dynamics, and radiative processes in the innermost emitting regions of accreting SMBHs that are otherwise difficult to probe. I will give a brief overview on variability studies to understand the inner structures of quasars, with several examples such as the measurement of the sizes of the accretion disk and the gaseous broad-line region with light echos, and the discovery and characterization of extreme variability events that challenge current accretion theories. Finally I will discuss the prospects of advancing quasar science in the upcoming time-domain era of LSST.

Professor Xin Liu (Department of Astronomy, University of Illinois at Urbana-Champaign)

"Finding low-frequency gravitational wave sirens in the electromagnetic sky"

時間/地點: 2018-12-21 14:00 [S4-1013]

摘要:

Binary supermassive black holes are expected to be common from galaxy mergers. Their final coalescence is believed to be the loudest gravitational wave siren in the universe, yet no confirmed binary is known to be close enough so that it would efficiently emit gravitational waves to merge within the age of the universe. Over the past few years, systematic searches using synoptic surveys based on active galactic nucleus variability have started to yield a sample of intriguing candidates. I will review the results from these searches and discuss future prospects to confirm systems that are directly emitting low-frequency gravitational waves.


特別學術演講列表

日期講者講題
2019-01-04Dr. Cheng-Ling Kuo
(Institute of Space Science, NCU)
Preliminary Results for Hyperspectrograph for Space Missions
2018-12-21Professor Yue Shen
(Department of Astronomy, University of Illinois at Urbana-Champaign)
The final parsec: time-domain exploration of the inner regions of quasars
2018-12-21Professor Xin Liu
(Department of Astronomy, University of Illinois at Urbana-Champaign)
Finding low-frequency gravitational wave sirens in the electromagnetic sky
2018-12-14Dr. Yuki Inoue
(Dept. of Physics, NCU)
Progress of KAGRA Gravitational wave interferometer and multi-messenger astronomy
2018-12-07Dr. Yu-Jung Chen
(Dept. of Physics, NCU)
The evolution of laboratory measurement of photodesorption of ices
2018-11-30Dr. Shiang-Yu Wang and Dr. Youichi Ohyama
(ASIAA)
SPICA-Taiwan: New Opportunities for MIR-FIR Science in 2030s
2018-11-23Dr. Chow-Choong Ngeow
(Institute of Astronomy, NCU)
Learning About RR Lyre in One-Hour
2018-11-16Dr. Ekaterina Koptelova
(Institute of Astronomy, NCU)
Molecular gas around supermassive black holes of quasars at redshift z>7
2018-11-13Dr. David Jewitt
(Department of Astronomy, UCLA)
Two Freaks and a Conundrum
2018-11-09Dr. Ying-Tung Chen
(ASIAA)
Exploring Outer Solar System with Large Programs of CFHT and Subaru
2018-11-02Dr. Yong Tian
(Institute of Astronomy, NCU)
Is Dark Matter REAL?
2018-10-26Prof. Wen-Ping Chen
(Institute of Astronomy, NCU)
Journey to the West: My Sabbatical Adventures
2018-10-19Prof. Yuan-Hann Chang
(Dept. of Physics, NCU)
Study the cosmic rays with the AMS experiment on the International Space Station
2018-10-12Dr. Chi-Ju Wu
(Max Planck Institute for Solar System Research)
From the Sun to climate: solar activity over the last 9000 years
2018-10-12Dr. Robin Thor
(Max Planck Institute for Solar System Research)
Constraints on planetary interiors from laser altimetry
2018-09-28Dr. Po-Chieh Yu
(Institute of Astronomy, NCU)
ZTF Update