Jet-Gas Interactions in Seyfert Galaxies

1. Jet-Gas Interactions in Seyfert Galaxies Mark Whittle (Virginia) David Rosario (Virginia) John Silverman (Virginia) Charlie Nelson (Drake) Andrew Wilson (Maryland)

2. Outline • Brief review of : AGN & Jets & Emission lines Reasons to study jet-gas interactions (JGI) • Case study of Seyfert Galaxy : Mkn 78 Observations & data overview Heuristic description of JGI Ionization analysis Dynamical analysis

3. Active Galaxies • All galaxies have nuclear black holes • Those currently accreting are “active” • Accretion energy released in two forms

4. A : Photons • Thermal & non-thermal processes • Broad SED : Optical / UV / X-ray • Large range in luminosity : LINER  Seyfert  QSO

5. AGN Spectral Energy Distribution (SED) Radio far-IR optical EUV X-ray

6. Seyferts (NGC 4151) Low Luminosity Quasars High Luminosity

7. B : Bipolar Outflows (Jets) • Origin uncertain (MHD driven ?) • Velocity uncertain : • Some relativistic, others not • Content uncertain : (p+e- or e+e- ?) • Relativistic component : e- + B  radio • Other (thermal) components ? • Large luminosity range : • Radio loud (radio galaxies/QSRs) • Radio quiet (Seyferts/QSOs)

9. Seyfert Galaxy Mkn 573 Flux ~ few mJy Radio Quiet Radio Galaxy 3C 296 Flux ~ few Jy Radio Loud

10. Emission Lines • From ionized gas : • Te~ 104K, ne~ 102 – 109 cm-3 • Ionization mechanism ? • Photoionization (yes) • Shock related (maybe with jets?) • Profiles reveal (Doppler) velocities • BLR (R ~ 10-2pc, V2~ GMBH/R) • NLR-1 (R ~ 1 kpc, V2~ GMbul/R) • NLR-2 (R ~ 1 kpc, V ~ jet related) • Nested emission line regions • BH << AD << BLR << NLR << Gal • r/c : min hr week 103 yr 104 yr

11. Why study JGI in Seyferts ? • Jet-gas interactions occur in many contexts • AGN (ISM/IGM) • Stellar jets (DMC/ISM) • Starburst winds (ISM/IGM) • Laboratory for astrophysical hydrodynamics • Seyfert ELRs allow important diagnostics • Gas mass, velocity, KE, momentum, pressure • Complements radio source pressure/energy

12. Mkn 78 : jet-gas archetype Early ground based data suggest prominent JGI : • Luminous triple radio source • Strong double [OIII] profile • FWHM >> gravitational velocities

13. Mkn 78

14.  Need HST resolution Unfortunately, Mkn 78 is quite distant : • cz ~ 11,000 km/s  1 arcsec ~ 700pc • BT ~ 15.2 MB ~ -20.8 • Dull looking early type galaxy

15. Mkn 78 KPNO 2.1m Red Continuum 30 arcsec

16. Mkn 78 : HST & VLA Dataset • VLA : 3.6cm 8hr map • HST images : (FOC, PC, STIS, NICMOS) • Continuum : UV/green/near-IR • Emission line : [OIII] 5007 • HST spectra : (STIS, FOS) • 4 slits : good spatial coverage • 4 gratings : low resolution : UV & optical high resolution : [OIII] 5007

17. Near IR NICMOS F160W arcsec Optical STIS CCD clear Dust lane

18. [OIII] λ5007 arcsec 3.6cm radio

19. 4 STIS Slit Positions

20. STIS low dispersion spectral data

21. STIS high dispersion [OIII] 5007 data

22. Mkn 78 Case Study :Jet-gas interactions • Heuristic description • Ionization study • Dynamical study • Jet properties

23. Overlay : Radio (contours) & [OIII] (image)

24. STIS high dispersion [OIII] 5007 data

25. 1. Heuristic Description • Inner W-knot Jet ends & disrupts; some gas disturbance ?  DMC enters & disrupts flow; recent interaction • Eastern fan Jet deflected; split lines; “blow-back” shape ?  Cloud inertia deflects jet (doesn’t destroy it) ?  Radial + lateral motion induced (±300 on 400) ?  Intermediate age : begun to disrupt cloud • Outer W-lobe Components; complex velocity ; no bow shock ?  late stage; dispersing cloud remnants; leaky bubble

26. 2. Ionization Study Low dispersion spectra  many line fluxes Compare line ratios with : • Ionization models (U, Am/i , Shock) • Velocities (Vbulk & FWHM) • Location (radius) 4. Other things (radio/color/dust)

27. Ionization mechanisms Three basic contexts explored : • U – sequence : AGN photoionization • Am/i – sequence : AGN photoionization • Shock – sequence : shock ionization Cartoon illustrates these 

28. 1)U sequence 2) Am/i sequence Neutral Back Optically Thin clouds Ionized front AGN AGN Optically Thick Clouds Only Optically Thick & Thin Clouds UV UV Ferland’s, CLOUDY Binette et al : ‘96 Am/i = Am/Ai ~ 0.1 – 10 U = Ni/Ne ~ 10-2 – 10-3 3)Shock sequence Vsh shock Collisionally ionized & photo-ionized post-shock gas Auto-ionizing Shocks Photo-ionized precursor UV Vsh = 100 – 800 km/s Doptia & Sutherland : ‘95, ‘96, ‘03

29. Line ratios vs models • General excitation/ionization • Discriminators to separate Sh & U+Am/i • Discriminators to separate U & Am/i • [ [OI] 6300 anomalous line ] • [ Nuclear nitrogen enhancement ]

30. Excitation : All models OK U ~ 10-2 – 10-3 A ~ 30% – 90% Sh ~ 500 – 300 km/s U Am/i Sh

31. U Discriminators 1 Trends follow U & A Don’t follow shocks Am/i Sh

32. Discriminators 2 e.g. [NeV], HeII, & [OIII]4363 U poor, favours Am/i trend fits nicely Note : weak [NeV] in Mkn 78 requires new Am/i U Am/i Sh

33. Ratios vs models : Summary • Clean results because enough data to show trends • Current shock models are excluded • Photoionization by the AGN dominates • Gas contains both optically thick & thin clouds Now consider ratios vs gas velocity

34. Excitation vs FWHM Excitation vs V –Vsys Shock Shock Results summary 

35. Ratios vs velocity : Summary • Essentially no (v. weak) correlations :  ionization conditions independent of velocity 2. Shock model predictions very poor Now consider ratios vs radius

36. Excitation vs Radius • Radius : • Strong correlation •  photoionization • U drops ~ r –1  density ~ r –1 • [SII] difficult to confirm • Am/i drops with r •  more thin @ small r

37. Final check : UV Luminosity • Check photoionization : • Can UV luminosity power emission lines ? • But UV is invisible/obscured ?! • Take FIR luminosity = reprocessed UV • LUV~ LFIR~ 4πd2FFIR~ 4πd2 [2.6S60+ S100] • Check : • LUV~ Lem ~ 10 x L5007as observed • U ~ NUV/ne~ 10-2.5as observed

38. 3. Dynamical Study To go beyond heuristic description : • Need physical properties • Aim to evaluate these throughout regions • First consider ionized gas • Then consider other components

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

40. Extinction Density Line flux Mass Momentum KE

41. Simple Properties Three regions : Inner knot / East fan / West lobe Region Age : • 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 Consider other components 

42. The Various Components Thermal gas : nth; Pth; Tth Relativistic gas : ffrel; Prel ~ B2/8π Line Emitting gas : ffem; nem; Pem; Vem ISM nism~ 1 Assume/show : Prel~ Pth~ Pem ~ Pism

43. Pressures : Prel, Pem, Pth, Prad • Log P/k~ 6.5 / 6.0 / 5.5 K cm-3 • Quite high > radio galaxy lobes • All components deep within galaxy ISM • All pressures drop with radius (~ r -1) • As expected for galaxy ISM context • Approximate pressure balance between different components : Prel~ Pem (~ Pth) • Relativistic & radiation pressure too low to accelerate ionized gas (by ~x10) • Need dynamical (ram) pressure of jet

44. Energy Comparisons Relative energies in different parts : • UV (FIR) ~ 1000 (~1043 erg/s) • Emission lines ~ 1000 • Kinetic ~ 1 • Relativistic ~ 1 • Expansion /lobe ~ 1 • Radio ~ 0.2 Simple inferences 

45. Conclusions from energy comparisons • Photons dominate by x1000 ; Lem~ LUV  supports photo- over shock ionization  should not derive Ljet from Lem (see later) 2. Expansion / KE / Relativistic all similar  flows can accelerate gas & power radio source

46. 4. Jet Properties Estimating jet energy and momentum : Use emission line & lobe properties : • Ej~ KEem+αe Elobe~ 2-5 Elobe αe = synchrotron loss; adiabatic loss; ffrel Lj = Ej/Tage~ 2-5 x 1040 erg/s • Gj~αm Gem~ 2-5 Gem αm = covering factor loss ; drag loss Fj = Gj/Tage~ 2-5 x 1033 dyne

47. JET LUMINOSITY EKE ~ Σ½M V2 Lj Elobe~ PV ~ αeErel Lj~(EKE + αeErel )/tage JET MOMENTUM Gem ~ ΣM V Fj Fj~αmGem / tage αm~ αdrag αlcf ~ 2 – 5 αe~ αsyn αad αff ~ 2 – 10

48. Jet Properties (model) • Components: • Relativistic & thermal; ratio defined by ffrel • Both move at Vj • Pressure balance : Prel~ Pth • We know Prel from radio physics ~ Bme/8π • Energy : Ej~ KEth + Wth + Wrel • Wrel = (4/3)Prel ; Wth = (5/2) Pth • Momentum : Gj~ Gth + Grel = Gth • Relativistic component has ~zero inertia 2

49. Jet Properties (derived) Use Lj Gj Pj Aj to derive many properties (>100pc) • Thermal material dominates jet energy and momentum • Relativistic gas has little/no momentum • KEj/Uj~ Fj/Aj/Pj~ 10 / 3 / 2  KE dominates energy • Jet velocity~ 1-few x Vgas • 2Lj/Fj~ Vj~ 300 – 3000 km s-1 • Ram pressure dominates : Pram~ 30 / 7 / 4 x Prel • Can accelerate to Vem over Tage for Ncol~ 1021 cm-2 • Only mild shocks : Pram~ρemVsh2  Vsh ~ 10-50 km s-1 • Not acceleration by impulsive shocks; maybe wind/ablation

50. Jet Properties (derived) • Jet density (thermal) : 0.1 - 5 cm-3 • Consistent with entrained ISM • Jet temperature : Tj~ Pj/njk ~ 106 K • ~0.1-0.7 Temperature from thermalized Vj • again consistent with entrained ISM • Jet Mach number : 5 / 2.5 / 2  transonic • Consistent with entrainment and decollimation • Jet mass flux: ~ Mem over region lifetime • Could be entrained ISM • Could become ‘thermal’ component of lobe