Astronomy and Astrophysics Group

Very Large Array Radio Telescope
Very Large Array Radio Telescope

People

Academic staff

Research staff

Students

Prof. Kwong Sang CHENG
Prof. Allan Shi-Chung
CHEUNG (Chemistry)

Dr. Kai Ming LEE
Dr. Man Hoi LEE
(Adjunct with Department of Earth Sciences)

Dr. Jeremy J.L. LIM
Dr. Stephen Chi Yung NG
Prof. Quentin A. PARKER
Dr. Pablo, SAZ PARKINSON
Dr. Meng SU

Dr. Xuan FANG
Dr. Chin-Ping HU
Dr. Foteini LYKOU
Dr. Andreas RITTER
Ms. Wai Emily WONG



 

Mr. Alfred AMRUTH (MPhil)
Mr. Ho Cheung CHAN (MPhil)
Ms. Kam Ling CHAN (PhD)
Mr. Wai Kuen CHAN (MPhil)
Miss Yuk Ying CHAN (MPhil)
Ms. Vasiliki FRAGKOU (PhD)
Miss Lai Yee LEE (MPhil)
Mr. Yuan GAO (MPhil)
Mr. Junhao LI (MPhil)
Mr. Yihan LIU (MPhil)
Miss Jingyuan REN (PhD)
Ms. Kris Akira STERN (PhD)
Miss Zexi XING (PhD)
Mr. Fengwei YANG (PhD)
Mr. Wenhan ZHOU (PhD)

 

Research Activities

1.  Theoretical Astrophysics

The major research areas are related to neutron stars and pulsars, which are rapidly spinning and magnetized neutron stars, including X-ray and gamma-ray emission mechanisms, stellar structure, stellar cooling and heating mechanisms and the internal activities, e.g. sudden unpinning of superfluid vortices.  In addition to topics related to pulsars and neutron stars, we also study topics related to gamma-ray bursts, in particular the central engine problem, and high energy phenomena resulting from the stellar capture processes by supermassive black holes in the galactic center.

Dr. Lee is a planetary dynamicist who works on the formation and dynamical evolution of planetary bodies (planets, moons, etc.) in our Solar System and in planetary systems around other stars. He is also an expert in numerical methods for dynamical simulations of planetary systems. His current research interests include the dynamics and origins of (1) orbital resonances in extrasolar planetary systems, (2) planets in binary star systems, (3) the orbital architecture of the planets in our Solar System, and (4) the satellite systems of Jupiter, Uranus and Pluto-Charon.

2.  Observational Astrophysics

(1) Star Formation and Cooling Flows in Galaxy Clusters
Dr. Lim's research has spanned a broad range of topics, including (i) stellar coronal magnetic activity, (ii) the formation and late evolution of stars in our Galaxy, (iii) star formation and AGNs in nearby galaxies, (iv) X-ray cooling flows in galaxy clusters, and (v) astrophysical applications of gravitational lensing, including weighing supermassive black holes, studying young galaxies, as well as the nature of dark matter. The present focus of his work is on topics (iii)-(v). As an observational astronomer, Dr. Lim uses primarily radio telescopes (e.g., VLA, SMA, ALMA) and optical-infrared telescopes (e.g., CFHT, HST). Dr. Lim has mentored many graduate students, a number of whom have gone on to PhD programs in the USA and Europe, or have since become postdoctoral fellows. He collaborates with many astronomers worldwide, bringing international exposure to his students. Over the past 5 years, in collaboration with Prof. Thomas Broadhurst at Ikerbasque, Spain, Dr. Lim has built a strong group of undergraduate and graduate students working on gravitational lensing at HKU. Dr. Lim actively recruits talented undergraduate students for casual research in preparation for their capstone and graduate studies.

(2) Dr. Ng studies extreme objects in our Galaxy, including magnetars, energetic pulsars, pulsar wind nebulae (PWNe), and supernova remnants. He has led observational projects using world-class telescopes in X-rays and radio, such as the Chandra X-ray Observatory, XMM-Newton, the Expanded Very Large Array, and the Australia Telescope Compact Array. He has identified a pulsar moving at an enormous velocity over 2,000 km/s. He has also developed a powerful 3D modeling technique to capture the X-ray torus and jet morphology of PWNe and to measure the structure and evolution of the supernova remnant 1987A.

Dr. Ng's latest research focuses on the magnetic fields of neutron stars and their environments. Employing X-ray observations, he measures the surface temperature of magnetars, which are stars with the strongest magnetic fields in the Universe, to understand their extreme properties and their connection with ordinary radio pulsars. In addition, he maps the magnetic field configurations of PWNe using radio telescopes, in order to probe the cosmic ray production and transport in these systems. Further information can be found at the webpage http://www.physics.hku.hk/~ncy/.

(3) Prof. Q.A. Parker arrived at HKU in March 2015 and is intent on establishing a world-leading group in late-stage stellar evolution that includes post-AGB stars, planetary nebulae and massive star ejecta including Wolf-Rayet shells and supernova remnants. This is assisted by i) the on-going appointment of Prof. Albert Zijlstra as a Hung Hing Ying Distinguished visiting professor to HKU who is a world leader in planetary nebula; ii) the appointment of several new postdoctoral research fellows: Dr. F. Lykou, Dr. Andreas Ritter and Dr. Xuan Fang and iiii) Three PhD students. Significant contributions to this research field have been made by this strong team including two HKU press releases (see https://www.ras.org.uk/news-and-press/2741-planetary-nebulae and http://www.scifac.hku.hk/news/any/planebulae). Exciting research opportunities exist for additional research postgraduate students to join the group. This group also has strong synergies to existing departmental expertise in late stage stellar evolution (including supernova remnants) and to the Laboratory for Space research (http://www.lsr.hku.hk).

(4) Dr. M. Su has a broad range of research interest, including Cosmic Microwave Background to study the Universe in the very beginning and the later evolution, observational high energy astrophysics (including gamma-ray and X-ray telescopes), searching for Dark Matter particles, cosmic ray physics (both theory and observations involving both ground-based and spaceborne instruments). We are building a CMB telescope in the west part of Tibet , which is the highest observatory worldwide! We have launched the very first Chinese astronomy satellite to look for dark matter, named Dark Matter Particle Explorer (we found some hints!). He has discovered a pair of gigantic bubbles emitting high energy of gamma-ray photons using NASA’s Fermi Gamma-ray Space Telescope. He is also building satellites for dedicated space science research, including a X-ray telescope using so-called Lobster-eyed type of optics to enable the largest field of view ever, a UV telescope to help to find habitable worlds in other solar systems. He is also working on the two largest payloads onboard the future Chinese space station: a 2-meter class optical telescopes, and the High Energy Radiation Detector which is the future of the gamma-ray and cosmic-ray detection. If you are interested in studying the Universe (or the earth!) using satellites, please talk to him.

Some Representative Publications

(For the complete publication list of the department, please go back to Research.)


Prof. K.S. Cheng

  1. "Probing gamma-ray emissions of Fermi-LAT pulsars with a non-stationary outer gap model", Takata, J., Ng, C. W., Cheng, K. S., MNRAS, 455, 4249-4266 (2016)
  2. "Origin of the Fermi Bubble", K.S. Cheng, D. Chernyshov, V. Dogel, C.M. Ko and W.H. Ip, The Astrophysical Journal Letters, 731, L17: 1-4 (2011) 
  3. "A Three-Dimensional Outer Magnetospheric Gap Model for Gamma-Ray Pulsars: Geometry, Pair Production, Emission Morphologies, and Phase-Resolved Spectra", K.S. Cheng, M. Ruderman and L. Zhang, The Astrophysical Journal, 537, 964-976 (2000). 
  4. "High-energy Radiation from Rapidly Spinning Pulsars with Think Outer Gaps", L. Zhang and K.S. Cheng, The Astrophysical Journal, 487, 370-379 (1997)
  5. "Energetic Radiation from Rapidly Spinning pulsars. I: Outermagnetosphere Gaps", Cheng, K.S., Ho, C. & Ruderman, M., Astrophysical Journal, 300, 500-521 (1986)
     

Dr. J.J.L. Lim

  1. "A likely Supermassive Black Hole revealed by its Einstein radius in Hubble Frontier Field Image," Chen, M. C., Broadhurst, T., Lim, J., Diego, J. M., Ohyama, Y., Ford, H., & Benítez, N, The Astrophysical Journal, in press (2018)
  2. "Magnification Bias of distant Galaxies in the Hubble Frontier Fields: Testing Wave vs. Particle Dark Matter predictions," Leung, E., Broadhurst, T., Lim, J., Diego, J. M., Chiueh, T., Schive, H.-Y., & Windhorst, R., The Astrophysical Journal, in press (2018)
  3. "Geometric Corroboration of the Earliest Lensed Galaxy at z ≃ 10.8 from Robust Free-form Modelling," Chan, B. Y. M., Broadhurst, T., Lim, J., Diego, J. M., Zitrin, A., Coe, D., & Ford, H., The Astrophysical Journal, 835, 44 (2017)
  4. "The Role of Electron Excitation and Nature of Molecular Gas in Cluster Central Elliptical Galaxies," Lim, J., Dinh-V-T., Vrtilek, J., David, L. P., & Forman, W., The Astrophysical Journal, 850, 31 (2017)
  5. “The High-Velocity System: Infall of a Giant Low-Surface-Brightness Galaxy towards the center of the Perseus Cluster”, A. Yu, J. Lim, Y. Ohyama, J. C. C. Chan, & T. Broadhurst, The Astrophysical Journal, 814, 101 (2015)
  6. “A Rigorous Free-form Lens Model of A2744 to Meet the Hubble Frontier Fields Challenge”, D. Lam, T. Broadhurst, J.M. Diego, J.J.L. Lim, D. Coe, H.C. Ford and Z. Wei, The Astrophysical Journal, 697, 98 (2014)
  7. “Molecular Gas in the X-Ray Bright Group NGC 5044 as Revealed by ALMA”, L.P. David, J.J.L. Lim, et al., The Astrophysical Journal, 792, 94 (2014)
  8. "A Molecular Hydrogen Nebula in the Central cD Galaxy of the Perseus Cluster", J.J.L. Lim, Y. Ohyama, C.H. Yan, D.V. Trung and S.Y. Wang, The Astrophysical Journal, 744, 112 (2012)
     

Dr. S.C.Y. Ng

  1. "Chandra Phase-Resolved Spectroscopy of the High-Magnetic-Field Pulsar B1509-58", Chin-Ping Hu, C.-Y. Ng, J. Takata, R. M. Shannon, and S. Johnston, the Astrophysical Journal, 838, 156 (2017)
  2. “Discovery of a Synchrotron Bubble Associated with PSR J1015-5719”, C.-Y. Ng, R. Bandiera, R. W. Hunstead, and S. Johnston, the Astrophysical Journal, 842, 100 (2017)
  3. "Radio Polarization Observations of the Snail: A Crushed Pulsar Wind Nebula in G327.1-1.1 with a Highly Ordered Magnetic Field",Y. K. Ma, C.-Y. Ng, N. Bucciantini, P. O. Slane, B. M. Gaensler, & T. Temim, The Astrophysical Journal, 820, 100 (2016)
  4. "Hunting for Orphaned Central Compact Objects among Radio Pulsars", J. Luo, C.-Y. Ng, W. C. G. Ho, S. Bogdanov, V. M. Kaspi, & C. He, The Astrophysical Journal, 808, 130 (2015)
  5. "An anti-glitch in a magnetar", R.F. Archibald , S.C.Y. Ng, K.N. Gourgouliatos, D. Tsang, P. Scholz, A.P. Beardmore, N. Gehrels, J.A. Kennea, Nature, 497, 7451, 591-593 (2013)

 

Prof. Q.A. Parker

  1. “The binary fraction of planetary nebula central stars - III. the promise of VPHAS+”, H. Barker, A. Zijlstra, O. De Marco, D.J. Frew, J.E. Drew, R.L.M. Corradi, J. Eislöffel, Q.A. Parker, MNRAS, 475, 4504 (2017)
  2. “HASH: The Hong Kong/AAO/Strasbourg H-alpha planetary nebula database” Q.A. Parker, I. Bojcic & D.J. Frew, 11th Pacific Rim Conference held in Hong-Kong in Dec 2015, JPhCS, 728 (2016)
  3. “Fast, Low-ionization Emission Regions of the Planetary Nebula M2-42” A. Danehkar, Q.A. Parker, W. Steffen, The Astrophysical Journal, 151, 38 (2016)
  4. “The H-Alpha Surface Brightness - Radius Relation: A Robust Statistical Distance Indicator for Planetary Nebulae” D.J. Frew, Q.A. Parker and I. Bojicic, MNRAS, 455, 1459 (2016)
  5. “New light on Galactic post-asymptotic giant branch stars - I. First distance catalogue” S. Vickers, D.J. Frew, Q.A. Parker and I.S. Bojičić, MNRAS, 447, 1673 (2015)
  6. “Kathryn’s Wheel: A Spectacular Galaxy Collision Discovered in the Galactic Neighbourhood” Q.A. Parker, A.A. Zijlstra, M. Stupar, M. Cluver, D.J. Frew, G. Bendo and I. Bojici, MNRAS, 452, 3759 (2015)
  7. “Four New Planetary Nebulae Towards the Small Magellanic Cloud”, D. Draskovic, Q.A. Parker, W.A. Reid and M. Stupar, MNRAS, 425, 1402 (2015)
  8. “Spatially resolved kinematic observations of the planetary nebulae Hen 3-1333”, A. Danehkar, Q.A. Parker, MNRAS, 449, 56 (2015)
  9. “New light on Galactic post-asymptotic giant branch stars - I. First distance catalogue”, S.B.Vickers, D.J.Frew, Q.A.Parker and I.S. Bojicic, MNRAS, 447, 1673 (2015)

 

Dr. J.C.S. Pun

  1. "Measurement of cosmic-ray muons and muon-induced neutrons in the Aberdeen Tunnel Underground Laboratory" S. Blyth, et al. (Aberdeen Tunnel Underground Experiment collaboration), Physical Review D, 93, 072005 (2016)
  2. "The destruction of the circumstellar ring of SN1987A," C. Fransson, J. Larsson,... C.S.J. Pun, G. Sonneborn and B. Sugerman, The Astrophysical Journal Letters, 806, L19 (2015)
  3. "Contributions of artificial lighting sources on light pollution in Hong Kong measured through a night sky brightness monitoring network", C.S.J. Pun, C.W. So, W.Y. Leung and C.F. Wong, Journal of Quantitative Spectroscopy & Radiative Transfer, 139, 90-108 (2014)
  4. "The discovery of an X-ray / UV stellar flare from the late-K/early-M dwarf LMC 335," B.T.H. Tsang, C.S.J. Pun,R. DiStefano, K.L. Li and A.K.H. Kong, The Astrophysical Journal, 754, 107 (2012)
  5. "Observation of Electron-Antielectron Disappearance at Daya Bay" F.P. An, et al. (Daya Bay Reactor Neutrino Experiment collaboration) Physical Review Letters, 108, 171803 (2012)

 

Dr. M. Su

  1. “Degree-Scale Cosmic Microwave Background Polarization Measurements from Three Years of BICEP1 Data”, M. Su and BICEP1 Collaboration, The Astrophysical Journal, 783, 2 (2014)
  2. “Is the 130 GeV line real? A search for systematics in the Fermi- LAT data”, Douglas P. Finkbeiner, Meng Su, Christoph Weniger, Journal of Cosmology and Astroparticle Physics, 1, 29 (2013)
  3. “Evidence for Gamma-Ray Jets in the Milky Way”, Meng Su, Douglas P. Finkbeiner, The Astrophysics Journal, 753, 61 (2012)
  4. “Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?”, Meng Su, Tracy R. Slatyer, Douglas P. Finkbeiner, The Astrophysical Journal, 724, 1044-1082 (2010)
  5. “Impact of instrumental systematic contamination on the lensing mass reconstruction using the CMB polarization”, Meng Su, Amit P. S. Yadav, Meir Shimon, Brian G. Keating, Physical Review D, 79, 123002 (2009)
Last updated on 19 September 2018