EAVW 2018 Haneul Yang KASI/SNU Co-workers: Se-Hyung Cho, Youngjoo - - PowerPoint PPT Presentation

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EAVW 2018 Haneul Yang KASI/SNU Co-workers: Se-Hyung Cho, Youngjoo - - PowerPoint PPT Presentation

Nov 19, 2022 303 likes •447 views

EAVW 2018 Haneul Yang KASI/SNU Co-workers: Se-Hyung Cho, Youngjoo Yun, Dong-Hwan Yoon, Dongjin Kim, Hyosun Kim, Sungchul Yoon Interacting binary systems (cool giant + hot dwarf) Rich and complex circumstellar envelope (winds,

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SLIDE 1

Haneul Yang KASI/SNU Co-workers: Se-Hyung Cho, Youngjoo Yun, Dong-Hwan Yoon, Dongjin Kim, Hyosun Kim, Sungchul Yoon EAVW 2018

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  • Interacting binary systems

(cool giant + hot dwarf)

  • Rich and complex circumstellar

envelope (winds, accretion disks, bipolar jets)

  • excellent laboratory for exploring

various aspects of interactions and evolution in binary systems.

From the animation made by NASA

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SLIDE 3
  • SiO and H2O maser emission
  • SiO masers: nearby stellar surface
  • H2O maser: outside the dust layer
  • Giving the temperature, density, velocity of the maser-emitting

regions

  • Useful probe for investigating morphology and dynamics of the dusty

circumstellar envelope of the cool star

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SLIDE 4
  • Suspected, D(Dusty)-type symbiotic star
  • RA: 22 57 40.9676, Dec: +58 49 12.5578
  • M2-4II giant star + white dwarf (Kolotilov et al. 1991.)
  • Pulsation period: ~ 466 days (Kolotilov et al. 1997.)
  • LSR velocity: -54 km/s (GAIA)
  • A symbiotic star emitting strong SiO and H2O masers
  • (Cho et al. 2010)
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SLIDE 5
  • 4 band simultaneous observation with KVN
  • 22 GHz H2O and 43/42/86/129 GHz SiO masers
  • Single-dish observation
  • 2011/10/18~2018/06/15
  • 30 epoch
  • VLBI observation
  • 2015/01/23~2018/06/02
  • 22 epoch
  • First VLBI observation
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SLIDE 6
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SLIDE 7
  • Red cross  position of RG
  • The number of SiO maser spots
  • West: ~75%, East: ~25%
  • The average intensity
  • West: ~2.5 Jy, East: ~1.0 Jy
  • Trace of suspected outflow

motion in the SiO 43, 42 GHz maser at NW

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SLIDE 8
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SLIDE 9
  • H2O maser at only west-side
  • No blueshifted velocity at H2O

maser

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SLIDE 10
  • The reason of asymmetric

structure

a hot dwarf

  • H2O maser:

decayed by UV photon

  • SiO masers:

disturbed by wind interaction zone

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SLIDE 11
  • The reason of asymmetric

structure

a hot dwarf

  • H2O maser:

decayed by UV photon

  • SiO masers:

disturbed by wind interaction zone

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SLIDE 12
  • Find the exact position of hot dwarf
  • Estimate the unclear parameters
  • Separation
  • Orbital period
  • distance
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SLIDE 13
  • H2O, SiO masers in V627 Cas: asymmetric distribution
  • The effect of the hot dwarf
  • H2O maser: decayed by UV photon
  • SiO maser: disturbed by wind interaction zone
  • There are challenges to discover the position of WD in V627 Cas