C.C. Teddy CheungC.C. Teddy CheungNASA Goddard Space Flight CenterNASA Goddard Space Flight Centerand Eureka Scientific Inc.*and Eureka Scientific Inc.*

Teddy.Cheung@nasa.gov

Radio Galaxies in the Chandra Era8 July 20088 July 2008*Chandra GO7-8114C

High Redshift Relativistic JetsHigh Redshift Relativistic Jets

The Near, the Anticipated

Chandra View of Cen AJ. Goodger R. KraftC. Jones (earlier)

Kraft et al. (2001)

3C273 ROSATH. Marshall

Roser et al. (2000)M87 Einstein, VLA grayscale

Biretta et al. (1991)D. Harris (earlier)

Nearby (z<0.1) low-power FRIsContinuous steep declining

spectra X-ray variabilityCanonical synchrotron behaviorSites of particle acceleration

The Near, the Anticipated

SEDs compiled by Brunetti (2001)3C66b (Hardcastle et al. 2001); B2 0755 (Worrall et al. 2001)

Superluminal (βapp~10c) quasar PKS 0637-752 (z=0.65)

Very large jet: ~100/sinθ kpc = 600 kpc (θ=10o)

The Far, the Unanticipated

Chartas et al. (2000)Schwartz et al. (2000)

High-z Jets: a Different Phenomenon

PKS 0637 knot SED

SED from Uchiyama et al. (2006)See Chartas et al., Schwartz et al. (2000)Tavecchio et al. (2000) and Celotti et al.

(2001)

High-z Jets: a Different Phenomenon

PKS 0637 knot SEDRecall the FRIs looked like…

SED from Uchiyama et al. (2006)See Chartas et al., Schwartz et al. (2000)Tavecchio et al. (2000) and Celotti et al.

(2001)

TroughPeaked

Inverse Compton scattering of CMB?

SED from Uchiyama et al. (2006)See Chartas et al., Schwartz et al. (2000)Tavecchio et al. (2000) and Celotti et al.

(2001)

PKS 0637 knot SED

UCMBα(1+z)4 = 7.5x larger at z=0.65

Requires Γ2 boosting (Γ~3-15 on 100’s kpc)

Requires Υmin~10’s-100, implying large jet powers, 1048 ergs/s

Jets inferred to be near equipartition (UB ~Upart.)

The Far and Very Far

The Far and Very FarSeparate phenomena

at low-z (<0.1) & high-z (>0.1)

‘Excess’ X-rays symptom of z>0.1 jets (except Pic A – Wilson et al. 2001, Hardcastle & Croston 2005; 3C353 – Kataoka et al. 2008)

Separate phenomena at low-z (<0.1) & high-z (>0.1)

‘Excess’ X-rays symptom of z>0.1 jets (except Pic A – Wilson et al. 2001, Hardcastle & Croston 2005; 3C353 – Kataoka et al. 2008)

Ubiquitous problem (32 of 88 sources listed in XJET)

The Far and Very Far

This talk

Synchrotron vs. Inverse Compton

See Felten & Morrison 1966, Blumenthal & Gould 1970, Harris

& Grindlay 1979, Schwartz 2002

υX FXυR FR α(1+z)0 [synchrotron, ‘conventional’ models]

υX FXυR FR α(1+z)4 Γ2 [IC/CMB]

υX FXυR FR α(1+z)0 [synchrotron, ‘conventional’ models]

υX FXυR FR α(1+z)4 Γ2 [IC/CMB]

Synchrotron vs. Inverse Compton

See Felten & Morrison 1966, Blumenthal & Gould 1970, Harris

& Grindlay 1979, Schwartz 2002

We expect many bright X-ray jets at high-redshift even with modest beaming…

So where are they?!?

Very high-z Jet?

Schwartz (2004); ROSAT X-ray color and Radio Contours

GB J1713+2148, z=4 quasarApparent ‘jet knot’ in NVSS map (45”

resolution) coincident with bright ROSAT source

Very high-z Jet?

Schwartz (2004)

GB J1713+2148, z=4 quasarApparent ‘jet knot’ in NVSS map (45”

resolution) coincident with bright ROSAT source

z=4 quasar no radio jet

Field source with radio jet

Arcsec-resolution radio maps necessary for such studies

X-ray Jet in Radio Quiet AGN?

Schwartz et al. (2004)Optical grayscale; X-ray contours

Extended X-ray feature but quasar is radio-quiet: F(4cm) <0.2 mJy

No radio jet: low Υmax?If IC/CMB X-ray jet, lack

of optical emission implies very narrow particle distribution: Υmin~10’s, Υmax~1000’s

Current studies ‘biased’ toward radio-selected jets: need possible deeper radio (EVLA)

Jet?

Quasar CXOMP J0841+131z=1.9

X-ray Jet in Radio Quiet AGN?

Schwartz et al. (2004)Optical grayscale; X-ray contours

Jet?

Remember Pictor A!X-ray bright, radio faint jet

Extended X-ray feature but quasar is radio-quiet: F(4cm) <0.2 mJy

No radio jet: low Υmax?If IC/CMB X-ray jet, lack

of optical emission implies very narrow particle distribution: Υmin~10’s, Υmax~1000’s

Current studies ‘biased’ toward radio-selected jets: need possible deeper radio (EVLA)

Wilson et al. (2001)

Quasar CXOMP J0841+131z=1.9

Another X-ray (only) Jet at z=4.3?

Over 100 counts in 2.5” knot (17 kpc projected) in 90 ksec exposure

Siemiginowska et al. (2003)See also Yuan et al. (2003)

Known variable X-ray and flat-spectrum radio source (blazar)

UCMBα(1+z)4 = 100x larger than PKS 0637 (z=0.65)

No previously known radio jet…

Another X-ray (only) Jet at z=4.3?

Over 100 counts in 2.5” knot (17 kpc projected) in 90 ksec exposure

Siemiginowska et al. (2003)See also Yuan et al. (2003)

Radio/X-ray Jet at z=4.3

Here it is!

Siemiginowska et al. (2003)See also Yuan et al. (2003)

Cheung (2004)Radio contours, Chandra color

Radio/X-ray Jet at z=4.3

Cheung, Chatterjee, Brisken

VLBA pc-scale jet

Large projected bend in jet Cheung (2004)

Radio contours, Chandra color

Radio/X-ray Jet at z=4.3

Cheung (2004)Radio contours, Chandra color

Radio/X-ray Jet at z=4.3

Cheung (2004)Radio contours, Chandra color

υr Fr

υx Fx

Redshift Dependence?

Cheung (2004)

υx Fx

υr Fr

--------

Redshift Dependence?

Cheung (2004)

(setting alpha=1)See Tavecchio et al. (2006)

= --------υx Fx

υr Fr

Powerful jet (LR=4x1044 erg/s; LX~10 LR)Resolved jet structure (rather than single

feature)

B=…T_electronT_lightcross

Another High-z Jet, at z=3.9

Cheung, Stawarz, Siemiginowska (2006); only 20 ksec Chandra exposure

X-ray color and contours Radio color, X-ray contours

And Several More…

J2219-2719 Chandra detection Lopez et al. (2006)

Chandra cycle 7 snapshots of radio jets (with Stawarz, Siemiginowska, Schwartz, Harris, Wardle, Gobeille, Lee)

Detections (top row)non-detections (bottom row)

High-z Jet SEDs

υx Fx

υr Fr

Additional 5 GHz detection of GB1508 knot (Cheung, Wardle, Lee 2005)

Redshift Dependence?

Redshift (and Beaming) Dependence?

Lobe-dominated radio quasars

Includes several new (Cheung, Marshall, Hough, Bridle, Wardle)

Redshift (and Beaming) Dependence?

Larger δ increases fx/fr

Lobe-dominated radio quasars

Includes several new (Cheung, Marshall, Hough, Bridle, Wardle)

Four Challenges• X-ray emission mechanism and

physics through high-redshift jets [Radio imaging needs to catch up]

Jet Deceleration at High-redshift?

Kataoka & Stawarz (2005)

• At high-z, increase IGM density and clumpiness

• Increased dissipation; jets stifled - more disrupted (pc & kpc) morphologies?

• Slower jets? More rapid deceleration to kpc-scales?

Triples to Same Linear Scale

z = 3.891 z = 3.818 z = 3.464 z = 3.244 z = 3.076

z = 3.035 z = 2.877 z = 2.732 z = 2.707 z = 2.686

z = 2.660 z = 2.647 z = 2.582

342 kpc x 342 kpc boxes

Radio Imaging: Catching Up

SDSS/FIRST quasars; 154 sources z=2.5 – 5.5

Wardle, Gobeille, Cheung poster

Four Challenges• X-ray emission mechanism and

physics through high-redshift jets [Radio imaging needs to catch up]

• Synergy with gamma-ray (GLAST) observations [Chandra imaging of GLAST-LAT blazars]

Large-scale Jets as g-ray Sources

From Georganopoulos et al. (2006)See Marshall et al. (2001), Sambruna et al. (2001), Uchiyama et al. (2006), Jester et al. (2006)

3C273

Energy Transport from sub-pc / kpc

Tavecchio et al. (2005, 2007); also Schwartz et al. (2006)

See talks by Jorstad, MarscherPoster by Hogan (MOJAVE sources)

Leaving no g-ray Blazar Behind

See: http://glast.gsfc.nasa.gov/ssc/data/policy/LAT_Monitored_Sources.html

VLBA 2cm Survey map of PKS 1622-297Extended 14” feature – no map (Perley 1982)

Antonucci et al. (1986)

Reid et al. (1999)

NRAO 530 – 1 min. snapshot

S5 0716+714

Four Challenges• X-ray emission mechanism and

physics through high-redshift jets [Radio imaging needs to catch up]

• Synergy with gamma-ray (GLAST) observations [Chandra imaging of GLAST-LAT blazars]

• The low-energy spectra [Anticipate Chandra data necessary when LWA, LOFAR come online]

Where are the Low-E electrons?

In my opinion, if the LWA does nothing more than tell us something new about the low end of relativistic electron spectra, it would have been worth the effort!

-D.E. Harris (2005), Clark Lake to Long Wavelength Array Meeting

Where are the Low-E electrons?

PKS 0637-752 knot SED Inferred low-freq spectrum

Tavecchio et al. (2000)Schwartz et al. (2000); Chartas et al. (2000)

Harris & Krawczynski (2006)

The Case of 3C273

Originate from the same relativistic electrons…

What about lower-frequency emission?

The Case of 3C273

Originate from the same relativistic electrons…

MERLIN151 MHz

Conway et al. (1993)

The Case of 3C273

Originate from the same relativistic electrons…

MERLIN151 MHz

Conway et al. (1993)

The Case of 3C273

Originate from the same relativistic electrons…

MERLIN151 MHz

Conway et al. (1993)

Marshall et al. (2001) – Herman’s talk

The Case of 3C273

MERLIN151 MHz

Conway et al. (1993)

Jet

Core

The Case of 3C273

MERLIN151 MHz

Conway et al. (1993)

Jet

Core

Spectrum extends down to 10 MHzHelmboldt et al. (2008)

4321

Log Fv (Jy) 0-1

Steep-spectrum Excess Sources

How many others are there?

Cheung, Stawarz, Siemiginowska (2006)

Low-frequency Spectral Curvature

Low-frequency Spectral Curvature

Low-frequency break reduces LR; LX unchanged

Could explain flatter X-ray spectra (αX<αR)

May reduce the very large inferred δ factors

Possible explanation for discrepant B-field estimates in radio clusters/relics (Petrosian 2001)

Four Challenges• X-ray emission mechanism and physics

through high-redshift jets [Radio imaging needs to catch up]

• Synergy with gamma-ray (GLAST) observations [Chandra imaging of GLAST-LAT blazars]

• The low-energy spectra [Anticipate Chandra data necessary when LWA, LOFAR come online]

• Hybrid synchrotron + IC models? [Detailed modeling of 3C273, PKS0637-752]

Combined IC/CMB + Synchrotron?

Dermer & Atoyan (2002)

Klein-Nishina regime γ~108 / Γ (1+z)

Flattening υ~1017 δ BμG/ Γ2 (1+z)3 Hz

Uchiyama et al. (2006)

Thanks!• Especially to Aneta, Ralph, the LOC, SOC &

CXC