Discovery of an FRII microquasarDiscovery of an FRII microquasar

Manfred PakullManfred Pakull (Strasbourg Observatory)(Strasbourg Observatory)

Jess BroderickJess Broderick (Southampton) (Southampton)

Stephane CorbelStephane Corbel (Université Paris 7 and CEA Saclay (Université Paris 7 and CEA Saclay ))

Fabien Grise’Fabien Grise’ (University of Iowa)(University of Iowa)

Christian MotchChristian Motch (Strasbourg Observatory)(Strasbourg Observatory)

Roberto SoriaRoberto Soria (University College London)(University College London)

OutlineOutline

Energetics of S26: Energetics of S26: the most powerful microquasar known to datethe most powerful microquasar known to date

Introduction: ULX bubblesIntroduction: ULX bubbles

NGC 7793 S26: multiband studyNGC 7793 S26: multiband study X-ray core + X-ray/radio lobes + ionized bubbleX-ray core + X-ray/radio lobes + ionized bubble

Radio loud and radio quiet states Radio loud and radio quiet states

Holmberg IX X1Holmberg IX X1

Pakull & Mirioni 2002Pakull & Mirioni 2002Grise’ et al 2008Grise’ et al 2008

IC342 X1 (“foot nebula”)IC342 X1 (“foot nebula”)Pakull & Mirioni 2002Pakull & Mirioni 2002Feng & Kaaret 2008Feng & Kaaret 2008

HHHSTHST

No radio nebula (F <~ 0.1 mJy)No radio nebula (F <~ 0.1 mJy)

No radio nebula? No radio nebula?

LLxx ~ 1—2 E 40 erg/s ~ 1—2 E 40 erg/s

LLmechmech ~ 1 E 40 erg/s ~ 1 E 40 erg/s

LLxx ~ 1 E 40 erg/s ~ 1 E 40 erg/s

LLmechmech ~ few E 39 erg/s ~ few E 39 erg/s

NGC1313 X2NGC1313 X2

Grise’ et al 2008Grise’ et al 2008Grise’ et al 2011 in prepGrise’ et al 2011 in prep

No radio nebula No radio nebula (F <~ 0.1 mJy)(F <~ 0.1 mJy)

LLmechmech ~ few E 39 erg/s ~ few E 39 erg/sLLxx ~ 0.5—2 E 40 erg/s ~ 0.5—2 E 40 erg/s

Holmberg II X1Holmberg II X1Miller, Mushotzky & Neff 2005Miller, Mushotzky & Neff 2005

NGC5408 X1NGC5408 X1Kaaret et al 2003Kaaret et al 2003Soria et al 2006Soria et al 2006Lang et al 2007Lang et al 2007

ULX radio bubbles found in:ULX radio bubbles found in:

……and of course and of course SS433SS433 in our Galaxy in our Galaxy

LLjetjet ~ 1 E 39 erg/s ~ 1 E 39 erg/s

S26 nebula discovered by Blair & Long 1997S26 nebula discovered by Blair & Long 1997

Previously interpreted as an SNR (Pannuti et al 2002)Previously interpreted as an SNR (Pannuti et al 2002)

NGC 7793 NGC 7793 (d ~ 3.9 Mpc)(d ~ 3.9 Mpc)

M Pakull discovers a triple X-ray source M Pakull discovers a triple X-ray source from Chandra data (2007)from Chandra data (2007)

LLxx ~ 1.2E37 erg/s ~ 1.2E37 erg/s

LLxx ~ 6E36 erg/s ~ 6E36 erg/s

thermal plasma thermal plasma kT ~ 0.3—0.9 keVkT ~ 0.3—0.9 keV

thermal plasma thermal plasma kT ~ 0.3—0.9 keVkT ~ 0.3—0.9 keV

LLxx ~ 7E36 erg/s ~ 7E36 erg/sPower-law Power-law ~ 1.5~ 1.5

LLxx ~ 6E36 erg/s ~ 6E36 erg/s

thermal plasma thermal plasma kT ~ 0.5 keVkT ~ 0.5 keV

Combined hot spotsCombined hot spots

CoreCore

ChandraChandra spectra spectra of the X-ray of the X-ray corecore ( = BH in low/hard state?) ( = BH in low/hard state?) and X-ray and X-ray hot spotshot spots (thermal emission, not synchrotron) (thermal emission, not synchrotron)

Radio spectral index:Radio spectral index: ~ -0.8 in the lobes (opt thin synchrotron)~ -0.8 in the lobes (opt thin synchrotron) ~ 0 in the bubble (free-free from ionized gas)~ 0 in the bubble (free-free from ionized gas)

Estimated flux of free-free radio emission in agreement with H-beta fluxEstimated flux of free-free radio emission in agreement with H-beta flux Bubble = shocked gas at T ~ 30,000 K and density ~ 1/cm3Bubble = shocked gas at T ~ 30,000 K and density ~ 1/cm3

VLA long-slit spectrumVLA long-slit spectrum shows velocity structure: expanding bubble + jet entrainmentshows velocity structure: expanding bubble + jet entrainment

Energetics of S26Energetics of S26

5/1376.0 tPR js

km/s250exp v

km/s275exp v

324 g/cm10 exp53 vRt s

jPHL 7727

10077.0 erg/s1038HL

pc100sR

erg/s10fewa 40jP

(Castor et al 1975, Weaver et al 1977)(Castor et al 1975, Weaver et al 1977)

From observations, we get:From observations, we get:

(expansion velocity from H(expansion velocity from H line width) line width)

(shock velocity from H(shock velocity from HHeIIHeII4686)4686)

Alternative estimate from radiative shock modelsAlternative estimate from radiative shock models

erg/s10fewa 40jPobserved (~ 10 times that of SS433)observed (~ 10 times that of SS433)

Mass swept up in the shell ~ 2E38 gMass swept up in the shell ~ 2E38 gTotal energy in the cavity ~ 1E53 ergTotal energy in the cavity ~ 1E53 erg

Assume magnetic field ~ in equipartition with relativistic energy densityAssume magnetic field ~ in equipartition with relativistic energy density

After reverse shock, After reverse shock, jet energy transferred tojet energy transferred to:: relativistic electrons (relativistic electrons ( ~ 1—1E5) ~ 1—1E5) non-relativistic electrons (non-relativistic electrons ( ~ 1) ~ 1) relativistic protons and He nucleirelativistic protons and He nuclei thermal gasthermal gas

Calculate synchrotron emission and radio flux densityCalculate synchrotron emission and radio flux density

only only a few E(-3)a few E(-3) of the jet power is given to relativistic electrons of the jet power is given to relativistic electrons

Energetics of S26Energetics of S26

Compare with observed radio flux densityCompare with observed radio flux density

We obtain that:We obtain that:

Characteristic age ~ 200,000 yrsCharacteristic age ~ 200,000 yrs

1.1. Estimate the Estimate the energy required to inflate the bubbleenergy required to inflate the bubble

Get direct estimate of mechanical powerGet direct estimate of mechanical power

From [p x V] of X-ray cavity From [p x V] of X-ray cavity (eg, 4pV = enthalpy of relativistic gas)(eg, 4pV = enthalpy of relativistic gas)From optical line emissionFrom optical line emissionFrom free-free radio emissionFrom free-free radio emission

2.2. Measure Measure radio synchrotron emission from lobesradio synchrotron emission from lobes

Estimate (1/k) x jet powerEstimate (1/k) x jet power

where (1/k) = fraction of power transferred to relativistic electronswhere (1/k) = fraction of power transferred to relativistic electrons

Calibration of 1/k is long-standing problem also for AGNCalibration of 1/k is long-standing problem also for AGN

S26 is a rare object with direct estimates of both proxiesS26 is a rare object with direct estimates of both proxies

(eg, Willott et al 1999)(eg, Willott et al 1999)

Cavagnolo et al 2010: relation between radio lobe luminosity Cavagnolo et al 2010: relation between radio lobe luminosity and power injected into the bubble, for a sample of AGNand power injected into the bubble, for a sample of AGN

Power in relativistic electrons ~ (1/100)—(1/1000) of the total jet powerPower in relativistic electrons ~ (1/100)—(1/1000) of the total jet power

S26S26

K=1K=1

How does a microquasar jet with average P ~ a few E 40 erg/s How does a microquasar jet with average P ~ a few E 40 erg/s fit with canonical BH states?fit with canonical BH states?

Radio loud and radio quiet accretionRadio loud and radio quiet accretion

Low/hard stateLow/hard state Radio loudRadio loud FRI galaxiesFRI galaxiesmicroquasarsmicroquasars

High/soft stateHigh/soft state Radio quietRadio quiet Radio-quiet QSOsRadio-quiet QSOs

VH stateVH stateULX statesULX states

Radio loud?Radio loud?(steady or flaring?)(steady or flaring?)

FRII galaxiesFRII galaxiesRadio-loud QSOsRadio-loud QSOsS26?S26?

Eddjet PP 1.0

?Eddjet PP

No jetNo jet

Possible schemePossible scheme

Three cases at accretion rates >~ Edd ?Three cases at accretion rates >~ Edd ?

Radio loud and radio quiet accretionRadio loud and radio quiet accretion

Eddjetbol PPL ~ Ultraluminous, radio-loud stateUltraluminous, radio-loud state quasars: quasars: PKS 0743-67PKS 0743-67 (L ~ P ~ 1E47 erg/s)(L ~ P ~ 1E47 erg/s) 3C143C14 (P ~ 5E45 erg/s, L ~ 3E45 erg/s)(P ~ 5E45 erg/s, L ~ 3E45 erg/s) ULXs: ULXs: Holmberg II X1Holmberg II X1 (L ~ P ~ 2E40 erg/s)(L ~ P ~ 2E40 erg/s) NGC5408 X1NGC5408 X1 (L ~ P ~ 1E40 erg/s)(L ~ P ~ 1E40 erg/s)

bolEddjet LPP ~ Kinetically-dominated ultra-high stateKinetically-dominated ultra-high state quasars: quasars: 3C823C82 (P ~ 1E47 erg/s, L ~ 1E46 erg/s)(P ~ 1E47 erg/s, L ~ 1E46 erg/s) 3C93C9 (P ~ 1E47 erg/s, L ~ 3E46 erg/s)(P ~ 1E47 erg/s, L ~ 3E46 erg/s) 3C4553C455 (P ~ 7E45 erg/s, L ~ 4E44 erg/s)(P ~ 7E45 erg/s, L ~ 4E44 erg/s) microquasars: microquasars: S26 S26 (P ~ 5E40 erg/s >> L)(P ~ 5E40 erg/s >> L)

jetEddbol PPL ~ Ultraluminous, radio-quiet stateUltraluminous, radio-quiet state

Most quasarsMost quasarsMany (most?) ULXs?Many (most?) ULXs?

(Punsly 2008, Punsly & Tingay 2007)(Punsly 2008, Punsly & Tingay 2007)

Radio loud and radio quiet accretionRadio loud and radio quiet accretion

bolEddjet LPP ~ Kinetically-dominated ultra-high stateKinetically-dominated ultra-high state quasars: quasars: 3C823C82 (P ~ 1E47 erg/s, L ~ 1E46 erg/s)(P ~ 1E47 erg/s, L ~ 1E46 erg/s) 3C93C9 (P ~ 1E47 erg/s, L ~ 3E46 erg/s)(P ~ 1E47 erg/s, L ~ 3E46 erg/s) 3C4553C455 (P ~ 7E45 erg/s, L ~ 4E44 erg/s)(P ~ 7E45 erg/s, L ~ 4E44 erg/s) microquasars: microquasars: S26 S26 (P ~ 5E40 erg/s >> L)(P ~ 5E40 erg/s >> L)

Mechanical feedback > radiative feedbackMechanical feedback > radiative feedback

Allows quasars to grow more quicklyAllows quasars to grow more quickly

May require high-spin BH May require high-spin BH and extraction of energy from BH spinand extraction of energy from BH spin

ConclusionsConclusions

ULX bubbles have mechanical power ~ 1E39—1E40 erg/sULX bubbles have mechanical power ~ 1E39—1E40 erg/s

S26 in NGC 7793 is first example of S26 in NGC 7793 is first example of collimated jetscollimated jets

Most of the jet power used to inflate the bubbleMost of the jet power used to inflate the bubbleOnly ~ 1E38 erg/s go into synchrotron-emitting electronsOnly ~ 1E38 erg/s go into synchrotron-emitting electrons

Largest and most powerful microquasar (160 x 290 pc)Largest and most powerful microquasar (160 x 290 pc) Linear size ~ 2.5 x SS433Linear size ~ 2.5 x SS433 Radio luminosity ~ 3 x Cas ARadio luminosity ~ 3 x Cas A Jet power ~ a few E 40 erg/sJet power ~ a few E 40 erg/s

Core is an optically bright (B ~ 23 mag) but X-ray faint sourceCore is an optically bright (B ~ 23 mag) but X-ray faint source(currently in the low/hard state? Fainter than average?)(currently in the low/hard state? Fainter than average?)

Rare example of kinetically-dominated ultra-high state in the local universeRare example of kinetically-dominated ultra-high state in the local universe(analogy with recently discovered sample of kinetically dominated quasars)(analogy with recently discovered sample of kinetically dominated quasars)

Work in progressWork in progress

HST imaging observations already approved, scheduled for July 2011HST imaging observations already approved, scheduled for July 2011

Re-apply for Chandra time Re-apply for Chandra time to determine accurate position and spectrum of the hot spotsto determine accurate position and spectrum of the hot spots

Re-apply for VLT spectroscopyRe-apply for VLT spectroscopy to determine mass and age of the optical counterpart (B ~ 23 mag)to determine mass and age of the optical counterpart (B ~ 23 mag) (and maybe mass function in the future?)(and maybe mass function in the future?)

Find a more appealing name than “NGC 7793 S26”Find a more appealing name than “NGC 7793 S26” (email suggestions to (email suggestions to roberto.soria@mssl.ucl.ac.ukroberto.soria@mssl.ucl.ac.uk))

Study polarization and Faraday rotation from new ATCA radio dataStudy polarization and Faraday rotation from new ATCA radio data

REFERENCES:REFERENCES: Pakull, Soria & Motch 2010, Pakull, Soria & Motch 2010, NatureNatureSoria, Pakull, Broderick, Corbel & Motch 2010, Soria, Pakull, Broderick, Corbel & Motch 2010, MNRASMNRAS