Radio Galaxies in X-Ray Light: Radio Galaxies in X-Ray Light: Problems and ProcessesProblems and Processes
Dave De YoungNOAO
Radio Galaxies in the Chandra Era
8-11 July 2008
Major Unresolved Issues â Radio Major Unresolved Issues â Radio Galaxies in the Pre-Chandra eraGalaxies in the Pre-Chandra era
⢠Origins of Energetic Particles â How and Where
⢠Formation of Bipolar Outflows
⢠Collimation Mechanisms
⢠Outflow Speeds
⢠Outflow Content
⢠Total Energies
⢠Outflow Lifetimes
Major âResolvedâ Issues â Radio Major âResolvedâ Issues â Radio Galaxies in the Pre-Chandra eraGalaxies in the Pre-Chandra era
⢠Morphology/Radio Luminosity Classification â FR-I and FR-II
⢠Radio Radiation - Incoherent Synchrotron
⢠Must Have Relativistic Electrons and Magnetic Fields
⢠âSuperluminal Featuresâ on Small Scales
Some Major Revelations from Some Major Revelations from ChandraChandra
⢠Extended X-Ray Emission From Jets, Hot Spots, and Lobes
Revelations from Chandra â Revelations from Chandra â Large Scale X-Ray JetsLarge Scale X-Ray Jets
⢠Electron Synchrotron Lifetimes in Equipartition Fields:â X-Ray: Decades to Centuries
â Optical and UV: Millennia
⢠Therefore High Energy Electrons Cannot Have Been Energized Only in Nucleus
⢠Immediate Impact on
Models
Revelations from Chandra â Low Revelations from Chandra â Low Power (FR I) X-Ray JetsPower (FR I) X-Ray Jets
⢠Electron Synchrotron Models Can Work⢠Single SED Can Fit Radio to X-Ray
⢠Requires Local Acceleration in Knots⢠Can Produce Offsets⢠Simultaneous Variations at X-ray to Radio
⢠Problems/Uncertainties:⢠Distributed Acceleration â Two Populations?⢠Occasional Wrong SED⢠No Radiative Cooling Signatures?
Revelations from Chandra â Hot Revelations from Chandra â Hot Spots and LobesSpots and Lobes
⢠X-Ray Emission Consistent with SSC and IC/CMB Under Equipartition Conditions
⢠First âVerificationâ of Equipartition Assumption
⢠Kataoka & Stawartz 2005, Croston et al. 2005
Revelations from Chandra â Large Revelations from Chandra â Large Scale (QSO, FR II, Blazar) X-Ray JetsScale (QSO, FR II, Blazar) X-Ray Jets
Schwartz et al. 2000Sambruna et al. 2004
Large Scale X-Ray JetsLarge Scale X-Ray Jets
Harris & Krawczynski 2006
Siemiginowska et al. 2007, 2008
Large Scale X-Ray JetsLarge Scale X-Ray Jets
⢠The IC/CMB Modelâ Tavecchio et al. 2000, Celotti et al. 2001
⢠PKS 0637-752: Π~ 10
⢠Reproduces SED
⢠Has Three Basic Assumptionsâ Equipartition Conditionsâ Relativistic Motion on 10-100 Kpc Scalesâ Population of Low Energy electrons
Schwartz et al. 2000
Large Scale X-Ray JetsLarge Scale X-Ray Jets
⢠Electron
Kataoka & Stawartz 2005
Large Scale X-Ray Jets â The Large Scale X-Ray Jets â The IC/CMB ModelIC/CMB Model
⢠Some Issuesâ Low Energy Îł ~ 10-100: Long Electron Lifetimes
⢠Why X-Ray Knots?
â Required Beaming Angles Imply Jet Lengths ~ 1 Mpc or More, >> FR II Jets
â Equipartition + Low Energy End of Spectrum May Imply âToo Muchâ Energy
â Bulk Speeds at 100s kpc >> Other Derived Values
IC/CMB IssuesIC/CMB Issues
Kataoka et al. 2008
3C 33 Kraft et al. 2007
Revelations from Chandra â Revelations from Chandra â Large Scale X-Ray JetsLarge Scale X-Ray Jets
⢠Reacceleration for Electron Synchrotronâ First Insights into Energy Injection Question
â Stringent Requirements on Shock Models
â Can Account for Most Low Power FR-I Jets
⢠Possibility of IC/CMB for FR-II/Quasar Jetsâ Requires Relativistic Bulk Motion at 100s kpc
⢠First Possible Clues to Jet Speeds on Large Scales
â Implies Low Energy Electron Population⢠First Possible Constraints on Îł(min)
Other Radio Galaxy Results Other Radio Galaxy Results from Chandrafrom Chandra
⢠Radio Galaxy Interactions with the Environment
⢠E.g., Cen A (Kraft et al. 2007)
More Major Revelations from More Major Revelations from ChandraChandra
⢠Radio Galaxy Inflated Cavities in Clusters
NGC 1285/Perseus
Fabian et al. 2000
Radio Source CavitiesRadio Source Cavities
⢠N1275
Fabian et al. 2000
Radio Source Cavities in Radio Source Cavities in ClustersClusters
⢠Chandra A2052 + 6cm VLA (3C 317)
Blanton et al. 2001, Burns 1990
Properties of Radio Source Properties of Radio Source Cavities and ShellsCavities and Shells
⢠Morphologyâ Limb Brightened, âRelaxedâ Structure
â NOT Head-Tail or âNormalâ FR-I
â Small/No Jets, but t ~ 10 yr
â Tens of kpc in Diameter
⢠Inferred Propertiesâ In Pressure Equilibrium
â Generally Moving Subsonically
â Shell and Surroundings Cool
â Buoyant Bubbles
7syn
Relic Sources in ClustersRelic Sources in Clusters
⢠N1275
74 MHz
Fabian et al. 2002
Properties of Radio RelicsProperties of Radio Relics
⢠They Are Intact! At Times >> t
⢠Reside 30-50 kpc From Cluster Center
⢠Diameter 10-20 kpc
⢠Buoyant Risetimes ~ 10 yr > Synchrotron Lifetime
⢠Equilibrium Implies U >> U
⢠PdV Work ~ 10 erg (or More)
int equip
59
instab
8
Calorimetry of Radio Galaxy Calorimetry of Radio Galaxy OutflowsOutflows
⢠After > 35 Years of Assumptions and Guessing
McNamara & Nulsen 2007
Calorimetry of Radio Sources in Calorimetry of Radio Sources in ClustersClusters
⢠MS 0735â Z = 0.22
⢠pdV ~ 10 erg!62
McNamara et al. 2005, 2007
Stability of Relic Sources in Stability of Relic Sources in Clusters Clusters
⢠t >> tbuoy R-T, K-H
vs
The âCooling Flowâ Problem and The âCooling Flowâ Problem and Heating Due to Radio SourcesHeating Due to Radio Sources
⢠Sound Waves?
⢠Shock Waves?
Fabian et al. 2005
P/P
What Have We Learned and What Have We Learned and What Remains Unsolved?What Remains Unsolved?
⢠Origins of Energetic Particles â In Situ Acceleration Required in Addition to Nuclear Processes
⢠Formation of Bipolar Outflows â ? See Finis
⢠Collimation Mechanisms â ? See Finis
⢠Outflow Speeds â May Be Relativistic on Mpc Scales
⢠Outflow Content â Coupled to Speed Question?
⢠Total Energies â Enormous Progress: Firm Limits
⢠Outflow Lifetimes â See Item 4
A Possible Path to Further A Possible Path to Further Progress â Jet Interactions With Progress â Jet Interactions With
Their EnvironmentTheir Environment
⢠Key Issue: The Coupling of AGN Outflow to the Surrounding Medium
â Ambient Medium with Known Properties
â Determination of Dominant Physical Processes at Work
â Constrain Basic Parameters of Outflow
AGN OutflowsAGN Outflows
⢠FRII
3C983C223 â 20cm
AGN OutflowsAGN Outflows
⢠FRI
AGN OutflowsAGN Outflows
⢠FRI
AGN OutflowsAGN Outflows
AGN OutflowsAGN Outflowsâ Surface Brightness
Outflow Interaction with Outflow Interaction with Ambient MediumAmbient Medium
⢠Fully Non-Linear K-H Instability:â Development of Turbulent Mixing Layer
Mixing LayersMixing Layers
⢠Thickness Grows with Distance/Time
⢠Mixing Layer Can Permeate Entire Jet
-RELHL )(v)/( CTan
Mixing LayersMixing Layers⢠Entrainment Very Effective
â âIngest â Digestâ Process
Mixing LayersMixing Layers⢠K-H and Mixing Layers in Supersonic Flows
⢠Relativistic Flowsâ 3D Simulations
⢠Rigidity
⢠Deceleration
⢠Development of
Shear/Mixing LayersAloy et al.; Marti et al. 1999-2003
The Effect of Magnetic FieldsThe Effect of Magnetic Fields
⢠Can Stabilize â In Principle
⢠Three Dimensional MHDâ For High Beta > 100
⢠Evolves to Turbulence⢠Turbulent B Amplification⢠Enhanced Dissipation due to Magnetic Reconnection
â Instability Remains âEssentially Hydrodynamicâ
Ryu et al. 2000
Mixing LayersMixing Layers⢠MHD Plus Relativistic
Mizuno et al. 2007
Outflow Interaction Via Outflow Interaction Via Surface InstabilitiesSurface Instabilities
⢠Virtually Universal (One Possible Exception)â Present at Some Level in Outflows in All
Environments
⢠Globalâ Involve Most of Jet Surface for Long Times
⢠Inevitable (?)â Very Special Circumstances Required to Prevent
Occurrence
Consequences of Mixing LayersConsequences of Mixing Layers
⢠Saturated Mixed Jets - and FR I Source Morphology
Consequences of Mixing LayersConsequences of Mixing Layers
⢠Entrainment
⢠Deceleration
⢠Spine/Sheath Structure
⢠Decollimation
⢠How Much of Each?â TanÎ ~ (Ď /Ď ) / M 3C223 â 20cm
1 2
Consequences of Mixing Layers: Consequences of Mixing Layers: IC/CMB ModelsIC/CMB Models
⢠Can Π~ 10 to ~ Mpc be Sustained?
⢠Other Measures of Î: v Structure
⢠Is U >> U ?
⢠Implications for Content
⢠What is âToo Muchâ Energy?
p B
Consequences of Mixing Layers: Consequences of Mixing Layers: IC/CMB Models â Other IssuesIC/CMB Models â Other Issues
⢠Evidence for Sustained Energy Transport
⢠Where are âDebeamedâ Jets?
⢠Probable Need for Jet Models
With Complex Internal Velocity
StructureHardcastle 2006
Another Possibility Another Possibility
⢠Poynting Flux Jetsâ Origins Well Defined
â Initial Collimation Solved
â Development of Mixing
Layer â Not Clear
â Long Term Collimation?
â Particle Content?
Li et al. 2006
Evolution of Turbulent FlowsEvolution of Turbulent Flows
⢠Development of the Turbulent Cascade
Issues for This WeekIssues for This Week
⢠The FRI / FRII Dichotomy (and IC/CMB Jets)â Difference in Degree or Kind?
â Nature vs. Nurture
â Jet Content
â Jet Speed
⢠Collimationâ Difficult with External Pressure ( ~ d )
â Difficult with Magnetic Fields
Issues for This WeekIssues for This Week
⢠Poynting Flux Jetsâ Are There Unique Observational Signatures?
⢠Radio Sources in Clustersâ Cooling Flows, Feedback etc.
â Consequences for General Radio Sources⢠Total Energies
⢠Energy Fluxes
⢠Outflow Speeds
⢠Jet Content