Home | Contact | Sitemap | 中文 | CAS
Search:
About Us Research People International Cooperation News Education & Training Join Us Journals Papers Resources Links
Location: Home > News > Seminars
News
  • Events
  • DAMPE
  • Seminars
  • Research Trends
  • X-ray Spectroscopy of Hot Plasma in and around Galaxies

     

    Seminar Title:

    X-ray Spectroscopy of Hot Plasma in and around Galaxies

    Speaker:

    Prof. WANG Qingde 

    Affiliation: 

    (Department of Astronomy, University of Massachusetts, Amherst, USA)

       

    When:

    Wednesday morning, Nov.9th , 10:00 a.m

    Where:

    Room 327, Office Block, 2 West Beijing Road (PMO, CAS)
     
     

    Welcome to Attend

     
      ( PMO Academic Committee & Academic Circulating committee)
     
     

     

    Abstract    
    Much of the baryon matter in the present universe is believed in the form of diffuse hot plasma in and around galaxies. However, little is so far known about the actual properties of this plasma. I will review recent spectroscopic studies of the plasma, based chiefly on X-ray grating data from Chandra and XMM-Newton. The X-ray absorption line spectroscopy has led to the first characterization of the spatial, thermal, chemical, and kinetic properties of the plasma in our Galaxy. The plasma is concentrated around the Galactic bulge and disk on scales of a few kpc. The column density of the plasma on larger scales appears to be at least an order magnitude smaller, indicating that it may not account for the bulk of the missing baryon matter predicted for the Galactic halo according to the standard cosmology. Similar results have also been obtained for other nearby galaxies. Furthermore, a substantial fraction of diffuse soft X-ray emission observed in nearby galaxies cannot arise from optically-thin thermal plasma and most likely originates in charge exchange at the interface with neutral gas, as indicated by the strong forbidden lines of the Kalpha triplets of He-like ions. In general, the bulk of the mass, energy, and metals from the stellar feedback is likely gone with winds in the galaxies. These galactic winds can have profound effects on the galactic ecosystem and evolution.

    Copyright? Purple Mountain Observatory, CAS, No.10 Yuanhua Road, Qixia District, Nanjing 210023, China
    Phone: 0086 25 8333 2000 Fax: 8333 2091 http://english.pmo.cas.cn