PowerPoint Presentation

The dynamics of microquasar jets in HMXBsRelativity meeting2013.10.27

DooSoo YoonUW-Madisonsupervised by Prof. Heinz1Interaction w/ medium

Cygnus X-1 (Gallo 2005)

M87, Virgo cluster (Hubble WFPC2)2013.10.27 Relativity Meeting @ UW-MilwaukeeDooSoo YoonLet me start from introducing briefly why Interaction and why compact object are so important. In fact, you know, measuring physical parameters directly around high energy object is often very difficult, so investigating those interactions of the jets with environment are really powerful for lots of cases in any scales from AGN to compact objects. For example, Here M87 jets, AGN in Virgo Cluster, you can see well resolved jet interacting with surrounding medium. This allows us to know its power of 10^44 erg/s, And one of famous X-ray binary systems, here Cygnus X-1 shows ring-like structure produced by the interaction between this collimated jet and ISM, This structure gives us lots of information about Cygnus X-1.

2Interaction w/ medium

Cygnus X-1 (Gallo 2005)Adavantage to study X-ray BinariesShort time scale and small physical scale allow us to study jet ejection episode (cf. AGN ~ 106 yr)The origin of accreting gas is rather clear.2013.10.27 Relativity Meeting @ UW-MilwaukeeDooSoo YoonI believe most of you know agree that compact object like X-ray binaries have great advantages that their dynamical time scale and physical scale is fairly acceptable, so it enable us to study the dynamical evolution of the jet. And it is also rather clear that accreting materials are transferred from its companion star by either roche-lobe overflow or direct wind capture. Those compact objects can be complimentary to AGN in order to understand complicated physics around black holes.

3Circum-binary environment

Sketch of Circum-binary environment (Fender & Maccarone, 2003)

M ~ 10-7 10-5 Myr-1.2013.10.27 Relativity Meeting @ UW-MilwaukeeDooSoo YoonWhat I want to present today is about the interaction of jets with stellar wind from companion star in High mass x-ray binary system. This is a sketch of circum-binary environment of high mass x-ray binary system from Fender and Maccarone 2003. You can see, this system consists of compact object like black hole, and companions star which is typically OB type or Be star. The wind from this companion star is so strong, therefore anyhow it should affect the nearby jet.

4Numerical Setup

3D Hydrodynamic simulation with FLASH3Ballistic Jet from cylindrical nozzleSpherical wind set to the typical parameters for OB type star

Parameter StudyJet power of 1035,1036,1037 erg s-1Jet orientation of 30, 60, 752013.10.27 Relativity Meeting @ UW-MilwaukeeDooSoo YoonIn order to study this particular system, we performed 3 dimensional hydrodynamic simulation by using FLASH3 code which is a modular, adaptive mash refinement, and parallel code.

To establish a jet, we used cylindrical nozzle outflowing jet both side here and for the stellar wind, we used spherical nozzle injecting gas isotropically.

Our simulations are carried out with several Jet powers and jet orientation with respect to the orbital angular momentum.

5Evolution of the jet

Orbital motionJet evolution2013.10.27 Relativity Meeting @ UW-MilwaukeeDooSoo YoonThese are movie clips from our simulation result. In this binary system, the black hole and the star rotate each other, and the jet is not yet to come out. Interesting feature is this kind of spiraling out tail which is gravitationally focused wind behind the black hole.

This is what happens when the jet is launched. When the jet is launched, the ejecta seem to be fairly straight due to high pressure. However, along the jet, the ejected plasma continues to be affected by the perpendicular momentum flux of the stellar wind pushing them backward. We found that interestingly the jet tends to converge into some asymptotic angle here, but this angle should depend on jet parameters and wind parameters. 6Analytic approach

Pressure equilibrium between theJet pressure and the wind ram pressure.

Jet bending angle:2013.10.27 Relativity Meeting @ UW-MilwaukeeDooSoo YoonWeve performed analytic approach with first order approximation, I mean, we assume small jet bending angle. Along the jet, pressure will be balanced between internal jet pressure and wind ram pressure. In this pressure equilibrium, we can derive analytical jet thickness along the jet. This plot shows jet thickness along the jet, solid lines represents numerical result, and different colors indicate different criteria to identify the jet. And dashed line represent analytic one. So it shows good accordance between numerically obtained jet thickness and analytic one. After doing some math work, we obtained the ratio of the accumulated wind momentum flux and jet momentum flux, and we consider it as jet bending angle. This relates to wind mass loss rate, wind velocity, separation, jet velocity, jet power, and if the jet is dynamically cold, this term will be negligible. As I say again, this analytic formula is based on the small jet bending approximation, so if the wind momentum flux is so strong for the jet to be bent largely, this formula may be not applicable, however we believe in lots of cases this is really still useful.

7Asymptotic angle

(Yoon et al. 2013, in preparation)Pjet = 1035 ergs s-1 Pjet = 1036 ergs s-1 Pjet = 1037 ergs s-1

For Cygnus-X-1,in order to develop a stable jet:

Pjet > 5.571035 erg s-1

agree with Gallo et al. 20052013.10.27 Relativity Meeting @ UW-MilwaukeeDooSoo YoonThese are logarithmic density maps in different jet powers. As you can see, there is obvious discrepancy of bending angle with the jet power. Here is combined figure, and each plus symbol trace jet, solid lines are fitted ones and dashed lines indicate analytic solution. Although It shows small deviation, were convincing this analytic formula works to constrain observational parameters on High mass x-ray binaries. We applied our formula to Cyngus X-1, and found that in order to develop a stable jet, I mean in order for the jet not to be destroyed by the stellar wind from companion star, the power of jet should be larger than 5.57 times 10^35 erg s^-1. This result is consistent with the jet power of Cygnus X-1 from Gallo et al. 2005. 8Off-axis jet

0306075Misalignment by natal kick (Brandt & Podisadlowski 1995)Alignment time scale align ~ 106108 yr (Martin et al. 2008)

The jet of Cygnus X-3 is inclined to the orbital plane (20