Xiaoying PANG - A comprehensive study of the young star cluster HD 97950 in NGC 3603

Date and Time: Friday Sept. 21st - 3 to 5 pm

Location: NAOC Room A308

Abstract: I study the young massive star cluster HD97950 located in the Galactic giant H II region NGC3603. 

My goals are (1) to investigate the origin of its mass segregation, and (2) to investigate the interplay between the cluster and the surrounding interstellar medium (ISM). All the studies are done with data of the Hubble Space Telescope. I determine the cluster velocity dispersion from the stars’ relative proper motions, and calculate the virial mass of the cluster.  I apply the   minimum spanning tree technique to measure the mass segregation down to 30 solar masses. The high-mass stars are more segregated than low-mass stars, implying that the mass segregation in HD97950 is mostly of dynamical origin. To improve the age determination for the cluster stars that are severely reddened by the surrounding dusty ISM, I compute a pixel-to-pixel distribution of the gas reddening, E(B-V )g, associated with the cluster. The radial profiles of E(B-V )g show significant spatial variations around HD97950. Using UBV RI photometry, I estimate the stellar reddening of cluster stars. After correcting for foreground reddening, the total to selective extinction ratio in the cluster is RV = 3.49 +/- 0.79. The extinction curve in the UBV RI filters in the cluster is greyer than the average Galactic extinction laws, but close to the extinction law for starburst galaxies. This indicates that stellar feedback from massive stars changes the dust properties in the HD97950 cluster in a similar way as in starburst galaxies.

Next Teeminars

Time Plan 2018/2017

Time and Place: 3:00 - 5:00 p.m., NAOC (unless noted otherwise); tbc = to be confirmed
  • Dec. 25: (note unusual Tuesday!): Sambaran Banerjee (Argelander Inst., Univ. Bonn, Germany): Stellar-mass black holes in open clusters: implications for gravitational-wave generation
  • Dec. 21: no tea seminar, MIDAS meeting
  • Dec. 11 (note unusual Tuesday!): Kohei Inayoshi (KIAA): Black hole accretion in the present-day and early universe; and general discussion on supercomputing in China
  • Dec. 7: no tea seminar, KCK10 at Suzhou
  • Nov. 30: no tea seminar
  • Nov. 23: Agostino Leveque (CAMK, Poland): The C MOCCA version: a step toward AMUSE
  • Nov. 16: Discussion with Mirek Giersz (CAMK, Poland)
  • Nov. 9: Sergey Khoperskov (Moscow/Garching)
  • Oct. 19/Nov. 2: no tea seminar
  • Oct. 12:
  • Oct. 5: vacation?
  • Sep. 28:Jongsuk Hong (KIAA): Stellar Evolution in Star Clusters: Applications
  • Sep. 21: Rainer Spurzem (NAOC): Discussion Meeting on Status of Stellar Evolution in NBODY simulations
  • Sep. 14: Planning Session and Reports
  • May 18: Shuo Li (NAOC): Multi-mass galaxy merger simulations




  • Dec. 15: note location and changed speaker: at KIAA Room 208: Shu Qi: Dynamic evolution of free-floating comets in star cluster / Taras Panamarev: N-body model of galactic center
  • Dec. 8: Li Shuo: Tidal disruption in galaxy mergers with Multi-mass and stellar evolution model.
  • Nov. 17: Verónica Vázquez: The merger of two quarks stars. A SPH Newtonian simulation
  • Oct. 27: Mirek Giersz (CAMK Warsaw, Poland): MOCCA - Survey Data Base - Projects (Black Holes and Gravitational Waves from Star Clusters)
  • Oct. 25 Lunch Seminar at KIAA (12:00 p.m.): Holger Baumgardt (Queensland Univ., Australia): The formation of the smallest galaxies
  • Oct. 20: Bohdan Novosyadlyj & Valerii Shulga (Ivan Franko Natl. Univ. of Lviv, Ukraine and Jilin Univ. China): Dark matter and dark energy probes: from Dark Ages to Giant Voids
  • Sep. 15: Xiaoying Pang: Open clusters from SDSS DR 14 | Bai Jing: Short Report on Galev Work | Rainer Spurzem: Short Status Report and Discussion of DRAGON Data Project
    • Sep. 7: Yohai Meiron (Eötvös University, Budapest, Hungary):  Relaxation and mixing of constants of motion in globular clusters
  • Sep. 1: Planning Meeting (Tea Seminar, Conferences, Travel)
      • Next Seminars:

  • Dec. 22: No tea seminar (KCK9)
  • Dec. 29:?


———Summer Break——————————————————

  • May 5: no tea seminar (Lazenby KIAA colloquium overlaps)
  • May 12: Alexandr Zhuk (Odessa  National University, Ukraine and Jilin University, China):  Cosmic screening of the gravitational interaction in the Universe (Abstract)
  • May 19: Xian Chen (DoA, PKU):   Retrieving the rest mass of GW150914  and Rainer Spurzem (Silk Road NAOC): News on NBODY6++GPU and Galactic Center DRAGON



  • Oct. 28: no tea seminar (EANAM7)
  •     Nov. 4: no tea seminar (CAS2016 Wuhan)
  •     Nov. 11: no tea seminar (KIAA Astro Forum)
  •     Nov. 14: DoA/PKU Lunch Talk: Abbas Askar: Monte Carlo Models
  •     Nov. 18: Li Shuo: Binary Black Holes in Merging Galaxies
  •     Nov. 25/Dec. 2: no tea seminar (China/South Africa workshop)
  •     Dec. 9: Matthias Kühtreiber: Galaxy Evolution Models
  •     Dec. 16: Shu Qi: Comets and Planets in Star Clusters/Taras Panamarev: N-Body models of Galactic Center
  •     Dec. 23: Jongsuk Hong: Multiple Populations in star clusters
  •     Dec. 28: Shuo Li: postponed to next year


Past Seminars in this period:


  • Sep. 16 Discussion Meeting with Guests
    1.) Thijs Kouwenhoven, Xian Jiaotong/Liverpool Univ. at Suzhou:
    Disk fragmentation and brown dwarfs in the Galactic field
     2.) Xiaoying Pang, Shanghai Inst. of Technology, on open clusters
     3.) Yohai Meiron, Eoetvoes Univ. Budapest, Hungary, on stellar disks in AGN
  • Sep. 23 at Room 410, Morningside Center of Mathematics near AMSS/CAS (location see link), 4:00 p.m.: Yohai Meiron, Eötvös University (Budapest, Hungary)Triple companion in gravitational wave signals (Abstract) (notice: postponed: Fabian Klein on Initial Models for AGN Disks using pluto)



Past Seminars