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KIAA-Cambridge Workshop The Formation of Peculiar Stars Zhanwen Han (Kunming)

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1 KIAA-Cambridge Workshop The Formation of Peculiar Stars Zhanwen Han (Kunming)

2 KIAA-Cambridge Workshop

3 Kunming Beijing Nanjing Shanghai

4 KIAA-Cambridge Workshop 正心问天 寻道兴文

5 KIAA-Cambridge Workshop 正心问天 寻道兴文

6 KIAA-Cambridge Workshop Current Projects Stellar Evolution Binary Related Objects Applications of Stellar Evolution Symbiotics Blue Stragglers Hot Subdwarfs Progenitors of SNe Ia, Companion Stars of SNe Ia 、 CEMP Contact Binaries Rapid Mass Loss Model Initial-Final Mass Relation Stellar Evolution with Alpha elements enhanced EPS model Stellar Populations of Galaxies Far-UV excess of early- type galaxies Chemical Yields of Stellar Population Gravitational Wave Radiation Background of the Galaxy Brown Dwarfs

7 KIAA-Cambridge Workshop Progenitor Model: Single Degenerate Model CO WD + MS CO WD + RG Double Degenerate CO WD + CO WD

8 KIAA-Cambridge Workshop Birthrates of SNe Ia from WD+MS Birthrate time Han, Podsiadlowski, 2004, MNRAS

9 KIAA-Cambridge Workshop Humuy: I ½ Livio: DD WD+AGB WD+Mira Delayed dynamically unstable RLOF Hamuy et al. 2003, Nature SN Ia 2002ic , Different Progenitor ?

10 KIAA-Cambridge Workshop 2002ic-like SNe Ia——delayed dynamical unstable RLOF model Han, Podsiadlowski, 2006, MNRAS

11 KIAA-Cambridge Workshop Comp. Mass Orb. Period

12 KIAA-Cambridge Workshop Properties of Companion Stars of SNe Ia Han, 2008, ApJL Space Velocity Comp. Mass Eff. Temperature Gravity

13 KIAA-Cambridge Workshop Rot. Velocity Comp. Mass

14 KIAA-Cambridge Workshop hot subdwarfs

15 KIAA-Cambridge Workshop Why hot subdwarfs important ? Stellar evolutionary theory Stellar seismology Distance indicator Structure and evolution of the Galaxy Far-UV excess (UV-upturn) of early type galaxies (age indicator ?)

16 KIAA-Cambridge Workshop Binary model To explain binary and single hot subdwarfs. Han, Podsiadlowski, Maxted, Marsh, Ivanova, 2002, MNRAS, 336, 449 Han, Podsiadlowski, Maxted, Marsh, 2003, MNRAS, 341, 669 Han, 2008, A&A, 484, L31

17 KIAA-Cambridge Workshop

18 Hot subdwarfs in globular clusters Extreme Horizontal Branch (EHB) stars Han, 2008, A&A, Letter

19 KIAA-Cambridge Workshop Han, Podsiadlowski, Lynas-Gray, 2007, MNRAS

20 KIAA-Cambridge Workshop Brown et al. 2003

21 KIAA-Cambridge Workshop GALEX Observations

22 KIAA-Cambridge Workshop Despite its simplicity, our model can reproduce lots of observations UV-upturn is universal (from dwarf to giant ellipticals) The magnitude of UV-upturn does NOT depend much on metallicity or redshift. UV-upturn is NOT an age indicator ! UV-upturn is explained naturally !

23 KIAA-Cambridge Workshop Thanks !

24 KIAA-Cambridge Workshop Composite Populations: old dominant + younger minor Given t major, variable f, t minor 8 supernovae in 6 of the 10 quiescent galaxies


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