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Seyfert Jets : weak, slow & heavy

Seyfert Jets : weak, slow & heavy. Mark Whittle (Virginia) David Rosario (Virginia) John Silverman (Virginia/CfA) Charlie Nelson (Drake) Andrew Wilson (Maryland). Markarian 78 provides ~ideal access to : Jet-gas interactions

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Seyfert Jets : weak, slow & heavy

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  1. Seyfert Jets : weak, slow & heavy Mark Whittle (Virginia) David Rosario (Virginia) John Silverman (Virginia/CfA) Charlie Nelson (Drake) Andrew Wilson (Maryland) • Markarian 78 provides ~ideal access to : • Jet-gas interactions • Nature of jets in radio quiet AGN AJ papers – I: Data, II: Ionization, III: Jet properties

  2. JET Overall Context } • Several inter-dependent components : Jet flowrelativistic material “Lobe”ionized line-emitting gas ISMthermal (low density) gas LOBE Relativistic gas : Line Emitting gas : ISM Thermal gas :

  3. Overall Context • Several physical processes : • entrainment of ISM by jet • acceleration of line-emitting gas • lobe expansion into ISM

  4. Available Data • Emission Line image : [OIII] (HST) • Radio image : 3.6cm (VLA) • Emission Line kinematics (HST-STIS) • Briefly review this 

  5. E-fan E-fan W-knot W-lobe Overlay : Radio (contours) & [OIII] (image)

  6. 4 STIS Slit Positions

  7. STIS low dispersion spectral data

  8. STIS high dispersion [OIII] 5007 data

  9. Slit B : kinematic measurements Peak Velocity FWHM -2 -1 0 +1 +2 +3 East Nuc West

  10. Extinction Density Line flux Mass Momentum KE

  11. Region Properties 3 regions : W-knot / E-fan / W-lobe Age~ size/velocity : ~ 0.4 / 4 / 8 Myr Ionized gas : Mass : ~ 0.4 / 1.0 / 1.1 x 106 Msun Filling factor : ~ 30 / 1.5 / 0.5 x 10-4 Covering factor : ~ 0.5 / 0.5 / 0.5

  12. Pressures : Prel, Pem, Prad • High: 1-few x 10-10 dyne cm-2 • All decrease with radius (~ r -1) • both consistent with presence in bulge ISM • Prel~ Pem (~ Prad) : • pressure balance between relativistic & ionized gas • Prelcan drive lobe expansion into ISM at V[OIII] • Prel & Prad can’tquite accelerate ionized gas • may need dynamical (ram) pressure of jet

  13. Energies & Luminosities : For each region, independently : LUV(intercept) ~ 1000 x 1040 erg s-1 Lem~ 10L[OIII]~ 1000 Lmec~KE/age ~ 1 Lrel ~ Erel/age ~ 1 (Lexp~1) Lradio~ 0.2 • NLR ionized by nuclear UV (not shocks) • Nuclear photon power dominates all others • KEgas & Eexp come from radio-emitting flow

  14. The Jet Flow • Jet properties are illusive – but important • Radio provides some access : • pressures, stored internal energy • Emission lines very useful : • estimate jet’s luminosity & momentum • We follow approach of Bicknell et al (’98) • But, with different starting assumptions • these lead to very different jet properties

  15. Starting Assumptions • Jet Luminosity : • B98 : Lj~ Lem~ 100L[OIII] (since shock generated) • W04 : Lj~ (EKE+αeErel)/age ~αeElobe/age • Lj(W) ~ 10-3 Lj(B) [~1040.5 erg s-1] • Jet Momentum Flux : • B98 : Fj/Aj ~ Pram~ ρemV2sh~ ρemV2[OIII] • W04 : Fj/Aj ~ Pram ~ αmGem/age /Aj • Fj(W) ~ 10-2Fj(B) [~1033.5 dyne]

  16. JET LUMINOSITY Emission Lines : Lem Bicknell et al ‘98 Shock Lj Lj~Lem~100 x L5007 Our analysis EKE ~ Σ½M V2 Lj ~1040.5 erg s-1 Elobe~ PV ~ αeErel Lj~(EKE + αeErel)/tage αe~ αsyn αad αff ~ 2 – 10 For Mkn 78 & other Seyferts : Lj (us) ~ 10-3 xLj (B98)

  17. Bicknell et al ‘98 Shock nem~ 103cm-3 ρemVsh Pram~ ρjVj2 2 Emission Line Cloud ρjVj2 ~ ρemVsh 2 Impulsive acceleration JET MOMENTUM FLUX Vsh~Vem~ 500 km/s Our analysis Gem ~ ΣM V Fj Gradual acceleration Fj~αmGem / tage ~1033.5dyne αm~ αdrag αlcf ~ 2 – 5 For Mkn 78 & other Seyferts : Fj (us) ~ 10-2 xFj (B98)

  18. Starting Assumptions • Jet Luminosity : • B98 : Lj~ Lem~ 100L[OIII] (since shock generated) • W04 : Lj~ (EKE+αeErel)/age ~αeElobe/age • Lj(W) ~ 10-3 Lj(B) [~1040.5 erg s-1] • Let Momentum Flux : • B98 : Fj/Aj ~ Pram~ ρemV2sh~ ρemV2[OIII] • W04 : Fj/Aj ~ Pram ~ αmGem/age /Aj • Fj(W) ~ 10-2Fj(B) [~1033.5 dyne] • Our jets are much weaker

  19. Derivation of jet properties } Model jet as 2 component system : 1 : Relativisticratio defined by filling factor : 2 : Thermalffrel = (1– ffth) assume pressure balance : Pth= Prel~ B2min/8π • Energy : Ej~KEth+(5/2) Pth+4Prel [KErel ~ 0] • Momentum : Gj~ Gth+ Grel~ Gth [Grel ~ 0] • Use estimates of Ej Gj Bmin Aj tage : to derive many jet properties

  20. Jet Properties • Jet energy (~1040.5 erg s-1) & momentum fluxes (~1033.5 dyne)both dominated by thermal gas • RKE = KEj/Eint= 10 / 2 / 1 (≡Mj2) • decrease suggests KE converted to internal • Ram pressure : Pram=Fj/Aj= 30 / 7 / 4 x Prel • Pram(W04) ~ 10-2 – 10-3 Pram(B98) • Our jet is gentle • Pram is significantly greater than Prel & Prad • hydrodynamic acceleration of ionized gas • shocks in ionized gas are slow~ 10-50 km s-1

  21. Jet Properties • Jet velocity : Vj= 2Lj/ Fj (1 + Rke-1) • Vj ~ 0.3 – 3 x 103 km s-1 ~1 – few x V[OIII] • cf. Vj (B98) ~ 15 – 90 x 103 km s-1 • our jet is slow • Jet density : ρj=Fj/PramAj~0.1–5cm-3 ~ρISM • consistent with entrained ISM • our jet is dense : η = ρj /ρISM ~ 1 • future simulations should consider η ~ 1 jets

  22. Jet Properties • Jet temperature & Mach # : • Tth ~ Pj /knth106.5– 107.5 K • temp ~ 0.2 – 0.7 fully virialized (cf. Pram >Prel) • Mj~ 5 / 2.5 / 1.5  jet istransonic  efficient entrainment & decollimation • Jet mass transport : Mth~Fj/ Vj~0.5 Msun yr-1 • Mthtage~ 106Msun ~thermal content of lobe • Jet supplies lobe’s thermal component ? · ·

  23. Jet Properties • Jet synchrotron efficiency : • Rsyn ~ Lradio /Lj~ Lradio tage /Elobe ~ 0.1 Fff P-103/4 t6~ 1-few % • similar to other radio sources (e.g. CSS & FR-I,II) • not obvious why : very different types of jet • cf. Rsyn(B98)~ 10-4 [ <<Rsyn(us)] •  sub-equipartition fields, or •  low ffrel  thermal component dominates

  24. Jet Base / Inner Jet • Previous analysis applies to scales > 100pc  thermally dominated flow; slow & dense • Is the flow created like this? • could it start with ffrel = 1.0, then entrain thermal gas • probably not : need Fj-b ~ Fj-kpc Lj-b > Lj-kpc S8Ghz < 3mJy • implies Vj-b~ c and Lj-b ~ 1043erg s-1 • Most energy lost in core  bright radio  not seen • Jet created with thermal component may define nature of radio quiet jets note : can’t be pure thermal (Rsyn too high)

  25. Conclusions • Mkn 78 gives excellent access to jet properties • Must combine radio and emission line data  pressure, internal energy, KE, momentum, age • For three regions, we find : • Age sequence; ~106 Msun; low ff; high cf; • P ~ PISM; Prel ~ Pem ~ Prad; lobe expansion ;V[OIII] • LUV & Lem dominate; shocks ; Erel~ EKE • Model jet as 2 component : relativistic & thermal • follow Bicknell et al ’98 but don’t use shocks • instead, take Lj ~αeElobe/tage ; Fj ~ αmGem /tage • derive jet properties 

  26. Conclusions • The jet is weak : Lj ~ 1040.5 erg/s; Fj ~ 1033.5 dyne • Thermal gas dominates jet energy & momentum • Pram~ 4 - 30 Pint: gentle jet • adequate to accelerate ionized gas • drives slow shocks into ionized clouds (10-50 km s-1) • Jet velocity~ 1-few V[OIII] : relatively slow jet • Jet density~ ρISM : dense jet • Transonic : Mj~2-5 ; Tth~106.5K ; Rsyn~normal • Thermal content may fill radio lobe • Jet base : jet created with thermal component

  27. New HST Project : 1 or 2 slits on six other objects with evidence for JGI.

  28. Comparison : Ours is a kinder, gentler jet. Maybe more plausible ?

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