rs oph : unstable disk model
DESCRIPTION
Xu Xiaojie 2009/05/20 reference : King & Pringle, arXiv: 0905.0637 Dewi & Tauris, 2000, A&A 360, 1043. RS Oph : Unstable Disk Model. ABCs of RS Oph. P=453.5 d, evolved giant companion (CVs have main sequence companion) - PowerPoint PPT PresentationTRANSCRIPT
RS Oph :RS Oph :Unstable Disk Unstable Disk
ModelModelXu XiaojieXu Xiaojie
2009/05/202009/05/20reference : King & Pringle, arXiv: 0905.0637reference : King & Pringle, arXiv: 0905.0637
Dewi & Tauris, 2000, A&A 360, Dewi & Tauris, 2000, A&A 360, 10431043
ABCs of RS OphABCs of RS Oph P=453.5 d, evolved giant companion P=453.5 d, evolved giant companion
(CVs have main sequence companion)(CVs have main sequence companion) Nova, Recurrent cycle ~ 21yrs Nova, Recurrent cycle ~ 21yrs
(1898--2006), relatively short;(1898--2006), relatively short; Bursting model:Bursting model:
1. unstable H burning on a massive 1. unstable H burning on a massive WD (~1.35M_s) surface, possible SN WD (~1.35M_s) surface, possible SN Ia progenitorIa progenitor
2. unstable accretion disk2. unstable accretion disk varying varying accretion rate, no heavy WD neededaccretion rate, no heavy WD needed
Observational Properties Observational Properties
Mixing of accreted matter and those Mixing of accreted matter and those of WD can cause WD matter lost of WD can cause WD matter lost during flashes: C, N, O, Ne, but no during flashes: C, N, O, Ne, but no significant sign for RS Ophsignificant sign for RS Oph
Well-collimated jets produced during Well-collimated jets produced during the outburst in 2006the outburst in 2006
Sources harboring jets ( quasars, Sources harboring jets ( quasars, microquasars, some X-ray binaries) microquasars, some X-ray binaries) have following in common:have following in common:disk accretion, high jet velocity, 10% disk accretion, high jet velocity, 10% accreted matter expelled, accreted matter expelled,
Theoretical DifficultiesTheoretical Difficulties
For nuclear bursting, to accumulate matter For nuclear bursting, to accumulate matter for outburst, accretion rate requiresfor outburst, accretion rate requires
While RS Oph lack of X-ray during While RS Oph lack of X-ray during quiescencequiescence
Matter in disk easily blow away Matter in disk easily blow away no jets no jets Nuclear burning hard to produce jetsNuclear burning hard to produce jets
JetsJets
Disk ModelDisk Model
P=453.5d P=453.5d a ~1.4AU a ~1.4AU Stable accretion requires M_2< M_1Stable accretion requires M_2< M_1 Stellar wind accretion ruled outStellar wind accretion ruled out RLOF forms an accretion disk, with RLOF forms an accretion disk, with
outer radius ~ 70% WD roche lobe, size outer radius ~ 70% WD roche lobe, size ~0.5a ~ 0.7AU ~ 10^12cm~0.5a ~ 0.7AU ~ 10^12cm
T of outer accretion disk less than T of outer accretion disk less than 6500K6500K
Disk unstableDisk unstable
Unstable Disk Unstable Disk
EquationsEquations
Equations IIEquations II
Irradiated DiskIrradiated Disk
Pros of Unstable DiskPros of Unstable Disk
Explanation of rising and decaying Explanation of rising and decaying of outburstof outburst
JetsJets Mass transfer rateMass transfer rate Large accretion diskLarge accretion disk Dynamical determination of the WD Dynamical determination of the WD
mass?mass?
Classic Evolution PathClassic Evolution Path
Classic Evolution Path IIClassic Evolution Path II
**2 mass less than WD mass ~~*2 accreted 2 mass less than WD mass ~~*2 accreted little matter~~ CE favoredlittle matter~~ CE favored
Orbital shrinking during CE, why P~450dOrbital shrinking during CE, why P~450d
CE?CE?
Less energy dissipation on CE phaseLess energy dissipation on CE phase Binding energy of the envelope Binding energy of the envelope
Total change in orbital energyTotal change in orbital energy
Energy converting efficiencyEnergy converting efficiency
Ejection & Binding Ejection & Binding ParameterParameter
Final separationFinal separation
The actual binding energyThe actual binding energy
Dewi’s CalculationDewi’s Calculation
Final SeperationFinal Seperation
Lambda for 3 Solar Mass Lambda for 3 Solar Mass StarStar
Happy Happy Birthday, Birthday,
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