Physics and astronomy are disciplines primarily driven by experiments and observations. The main research topics of our group is about observational studies of the fundamental physics involved in accreting black holes (BHs) and neutron stars (NSs) as well as in explosive or powerful transient events, making use of astronomical facilities in space and on the ground.
The group is led by Prof./Dr. Wenfei Yu, who worked as a postdoc in the world-leading Anton Pannekoek Institute for Astronomy of the University of Amsterdam and in the Center for Theoretical Astrophysics in the Department of Physics at the University of Illinois at Urbana-Champaign after he obtained his Ph.D in particle physics in 1998 from the Institute of High Energy Physics, Chinese Academy of Sciences. Even before, he obtained his MSc in theoretical astrophysics on black hole accretion theory. His group therefore has obtained unique research experience covering many aspects of high energy astrophysics and mutl-wavelength astronomy, i.e., observations, theory and instrumentation. While the group have access to a wide range of space or ground facilities through either competition or collaboration, the group are currently active members in the Scientific Working Groups (SWGs) of several planned international missions or proposed facilities, such as eXTP (China-EU joint X-ray timing mission), Sino-French GRB mission (SVOM), and the International Square Kilometer Array (SKA). Dr. Wenfei Yu was also holding a FAST Fellowship in 2017.
MeerKAT radio non-detection of the black hole transient V4641Sgr - see our report (Zhang et al. 2020, ATEL# 13471)
VLBA DDT observation of AT2019qiz - performed !
The Chinese SKA science documents: - we organized/coordinated the team work on radio transients
SKA 科学报告 和 Scientific Probe of Radio Transients
A 6 hour VLBA DDT observation of the nearest TDE AT2019qiz approved !
Collaborative JCMT large project PITCH-BLACK on black holes has just been accepted ! The project is a joint effort of more than 30 astronomers across the globe on black hole transients.
Confirmation of AT2019qiz in the rise of its radio emission (O'Brien, Kaplan, Murphy, Yu and Zhang 2019) ATEL #13334)
First detection of the nearest TDE - AT2019qiz in the radio with ACTA ! Joint effort from colleagues in Australia, US and Shanghai. See O'Brien, Kaplan, Murphy, Yu and Zhang 2019 ATEL #13310
Continuing monitoring of the candidate tidal disruption event AT2019qiz found in the rise, see also (Zhang et al. ATEL #13146; Zhang et al. ATEL #13193)
Link to observations taken
HXMT ToO observations of a new BH candidate MAXI J0637-430
Tracing the decay of MAX J1807+132 on a weekly cadence
X-ray flaring variability: Rapisarda et al. 2019 ATEL #13173
Link to observations
The first report from our group in the ThunderKAT collaboration - congratulations to Xian Zhang !
MeerKAT observations of MAXI J1807+132: non detection with upper limits at the ~ 100 uJy level (Zhang et al. ATEL #13142)
Discovery of quasi-periodic oscillation feature in MAXI J1807+132 with NICER from our group (Rapisarda et al. 2019, ATEL #13139)
Swift daily monitoring campaign of a tidal disruption event in the early rising phase AT2019qiz started !
Our first paper on Fast Radio Bursts (FRBs) "A search for short-term hard X-ray bursts in the direction of the repeating FRB 121102" has been accepted for publication in ApJ (Sun, Yu et al. 2019), available as arXiv:1909.07626. The study made use of the BAT on board the multi-wavelength space mission Swift.
The first NICER ToO observations (on the X-ray transient MAXI J1807+132) proposed from our group: congratulations to Stefano !
Multi-wavelength campaign on the X-ray transient MAXI J1807+132 in the ThunderKAT collaboration started. The X-ray transient MAXI J1807+132 was found in 2017 and now it undergoes its second outburst in history.
A heavyweight paper on relativistic astrophysics in tidal disruption events has just been accepted for the publication in ApJ
"Probing the Bardeen-Petterson effect in tidal disruption events with spectral line reverberation mapping" (Zhang, Yu, Karas & Dovciak 2019, ApJ):
"Time-resolved X-ray spectroscopy can be a powerful tool to probe the Bardeen-Petterson effect in TDE flares and can be used to measure the Bardeen-Petterson radius as well as put constraint on the black hole mass and spin." This will become one of the most exciting research topics of the eXTP mission in the time domain astrophysics era.
GRID is a student CubSats project led by Tsinghua Univ. to monitor the transient gamma-ray sky in the multi-messenger astronomy era. The first paper of the collaboration has just been accepted to publish in Experimental Astronomy.
Our collaboration with the Prague Relativistic Astrophysics group on the eXTP science on general relativistic effects is awarded grants from both countries - 中国-捷克科技合作委员会第43届例会人员交流项目获批(全国总共17个跨学科项目）。
Graduation ! Dr. Jie Lin is going for a postdoc in Tsinghua Univ., and MSc Miss Yuanming Wang is going to take a Ph.D fellowship to continue in the University of Sydney.
Progress of the China-EU Space eXTP mission: Science News 新闻
Science CHINA Physics, Mechanics & Astronomy: Special topic on the X-ray Timing and Polarimetry Frontier with eXTP
We co-led the contribution to the major scientific objective of the mission - the physics of the ultradense matter: "Dense Matter with eXTP" (Watts, Yu, et al. 2019)
Insight-HXMT (慧眼卫星) has just released the HXMT AO-2 Guest Observer Program. Five proposals on black hole and neutron stars are accepted from our group ! Congratulations !
MWA is one of the precursors of the SKA in Australia. It is a multi-million dollar international low-frequency telescope in Australia's Midwest. We just set up a research project on microquasars in the MWA collaboration.
We focus more on the physics might be learned from signals from the very vicinities of black holes and neutron stars:
Our first paper on Fast Radio Bursts (FRBs) "A search for short-term hard X-ray bursts in the direction of the repeating FRB 121102" has been accepted for publication in ApJ (Sun, Yu et al. 2019), available as arXiv:1909.07626. The study made use of the wide FOV X-ray instrument BAT on board the multi-wavelength space mission Swift.
The second paper on probing dormant supermassive black hole mass and spin and general relativistic effect in tidal disruption flares: "Probing the Bardeen-Petterson effect in tidal disruption events with spectral line reverberation mapping" (Zhang, Yu, Karas & Dovciak 2019, ApJ). Together with our first paper published in ApJ in 2015, these papers lay out the scientific motivation for our on-going ToO triggers for space X-ray observations.
The first collaboration paper from the GRID collaboration led by Tsinghua Univ: GRID - a student CubSats project to monitor the transient gamma-ray sky in the multi-messenger astronomy era (Wen et al 2019, Experimental Astronomy)
Outbursts of low mass X-ray binary transients: relation between the outburst rate and the orbital period (Lin et al. 2019, MNRAS)
Discovery of a new outburst of the black hole transient 4U 1630-47 and its soft energy spectra (Mao, Lin et al. 2018, ATEL #11722)
Discovery of a hard X-ray flare in SAX J1712.6-3739: A likely superburst in the NS LMXB on May 8th, 2018 (Lin & Yu 2018, ATEL #11623)
Further detection of the optical low frequency QPOs in the black hole transient MAXI J1820+070 again but with our Fast Optical Camera (FOC) (Yu et al. 2018, ATEL # 11591)
Discovery of optical low frequency QPOs in a newly discovered black hole transient MAXI J1820+070 with YFOSC on the Lijiang 2.4 m telescope (Yu et al. 2018, ATEL # 11510)
XMM-Newton AO-17: our proposal on extragalactic transients is awarded time again for joint XMM/Swift observations of a future TDE flare
State Transitions in Ultracompact Neutron Star LMXBs: towards the Low Luminosity Limit (Lin & Yu 2018, MNRAS)
Detection of X-ray Spectral State transitions in Mini-outbursts of Black Hole Transient GRS 1939-278 (Yan & Yu 2017, MNRAS)
Discovery of a New Outburst of the Black Hole Transient 1H 1743-322 (Zhang et al. 2017, ATEL # 10599)
Discovery of a New Outburst of the Ultraluminous X-ray Source ESO 243-49 HLX-1 (Yan & Yu 2017, ATEL #10137)
Multi-wavelength monitoring, X-ray timing and spectral analysis, and space or ground Target-of-Opportunity observations are widely used in our daily research. Here below are some of our primary research projects:
Project 1: X-ray Timing Studies of Black Holes and Neutron Stars - the Probe of General Relativity (GR) Effects and Ultra-dense Matter
Project 2: Relativistic Line Reverberation in Tidal Disruption Events – the Probe of GR Effects and Mass and Spin of Dormant SMBHs
Project 3: X-ray Monitoring of Black Hole and Neutron Star Transients and Multi-wavelength Target-of-Opportunity Observations – the Investigation of Black Hole Accretion and Jet Physics
Project 4: Energetic Transients in the Multi-wavelength Wide Field-of-View Era - X-ray Transients (Swift, MAXI, HXMT, SVOM), Radio Transients (SKA, FAST), Optical Transients (LSST)
Our research projects are supported by the following major PI grants:
NSFC Key Project (重点项目):
NSFC-CAS Key Project on HXMT Observations of X-ray Binaries (重点项目):
Dr. Zhen Yan (Ph.D of SHAO)
Dr. Shangyu Sun (current postdoc, Ph.D of MPIP 博士后引进交流项目)
Dr. Stefano Rapisarda (current postdoc, Ph.D of U of Amsterdam, CAS PIFI Fellowship 博士后引进交流项目)
Mr. Jie Lin (Ph.D student -> Tsinghua Univ. )
Mr. Dongming Mao (Ph.D student)
Ms. Yuanming Wang (MSc student -> Univ. of Sydney)
Mr. Bing Lv (joint Ph.D student - HUST)
Mr. Xian Zhang (MSc student)
Visiting scientists and students:
Dr. Wenda Zhang (visiting scientist - Ph.D of SHAO in 2015)
Dr. Hui Zhang (visiting scientist - Ph.D of SHAO in 2010)
Mr. Yuexin Zhang (2019 summer student - BSc of Fudan Univ. )
Dr. Holger Stiele (Ph.D of MPE, 2013.4-2015.2)
Dr. Yi Jung Yang (Ph.D of UvA, 2013.11-2014.7)
Dr. Wenfei Yu
Shanghai Astronomical Observatory
80 Nandan Road
Shanghai 200030, China
E-mail: wenfei @shao.ac.cn
[ version updated: 2019.6.1 wenfei @shao.ac.cn ]