Rays from Black Holes in X-Ray Binaries and Microquasars

Black Holes in the Galaxy from a high-energy astrophysics theory perspective

Chuck Dermer, NRL http://heseweb.nrl.navy.mil/gamma/~dermer/default.htm

Workshop on High Energy Galactic Physics 329 Pupin Hall, Columbia University May 28-29, 2010 Outline Energy from black holes γ-rays from black holes in X-ray binaries and microquasars – Leptonic jet model – Hadronic model – Colliding winds model – Synchrotron/γ-ray models Acknowledgement: γ rays from isolated black holes J. M. Paredes Galactic Center Black Hole

[Ultraluminous X-ray Sources]

Dermer VERITAS_NYC 28-29 May 2010 1 Cygnus Region

Cyg X-1, 5.6 d Cyg X-3, 4.8 hr

11/04/2008 2 Credit: B. Cerutti Black Holes Radio loud vs. radio quiet

Energy source: 2 kBT = hc / λ, λ → RS = 2GM / c 3 1. Evaporation ∴TH = hc /8πGM ∝1/ M Hawking radiation 2 4 −2 dT / dt ~ σ SB R T ∝ M

2. Accretion—Schwarzschild (1/12) vs. Kerr Low efficiency outflows, ADAFs X-ray and radio correlations for LMXBs Magnetic field prescription: B2~L/R2c Jet sources: something special? B(MG) ~ 200 l Edd / M1 /(R / Rg ) 47 2 P(erg / s) ~ 10 l Edd M 9 /(R / Rg ) 3. Rotation: Kerr Black holes, large a 2 BZ power: dE πB0 a a Blandford’s = [arctan( ) − ] conjecture (1990) dt ar+ r+ 2M Dermer & Menon (2009) 2 2 r±: ergosphere boundaries r± = M ± M − a Dermer VERITAS_NYC 28-29 May 2010 3 γ-rays from black holes in X-ray binaries and microquasars (Young) High-mass X-ray binaries (HMXBs) and (Old) Low-mass X-ray binaries (LMXBs): High and low mass refers to companion star, not compact object Accretion primarily through stellar wind (HMXB) and Roche-lobe overflow (LMXB) X-ray variability due to orbital timescale (pulsed emission rarely) Be X-ray binaries Microquasars: X-ray Binaries with Jets HMXBs thought to be γ-ray sources since COS-B and EGRET days

Dermer VERITAS_NYC 28-29 May 2010 4 Observer Black Hole Jet Physics: microquasars

θ Synchrotron/Compton BLR clouds Leptonic Jet Model Γ

Relativistically Collimated Target photons for scattering Plasma Jet Accretion regime

Accretion Ω High mass Disk Energy Sources: star BH 1. Accretion: wind, disk 2. Rotation Power Stellar Photons and Wind

Γ Ambient Identifying hadronic emissions Radiation Fields

Dermer VERITAS_NYC 28-29 May 2010 5 γ-ray Binaries and Candidates

3 confirmed γ-ray binaries from TeV data: – LSI +61 303. Pulsar/binary or black-hole binary/microquasar? (GeV source) – LS 5039. Pulsar/binary or black-hole binary? (GeV source) – PSR B1259-63. Pulsar/binary system. (GeV source?) Other (mostly high-mass) binaries are candidate GeV/TeV γ-ray binaries, but evidence is weaker: –Cyg X-3 (GeV source), Cyg X-1 (MAGIC source), Cen X-3, Her X-1, SS 433, A 0535+26, HESS J0632+057

A total of 280 X-ray binaries (circa 2006), including HMXBs: (131) Optical companion with spectral type O or B. Mass transfer via Be stars or via strong wind or Roche-lobe overflow. LMXBs: (149) Optical companion with spectral type later than B. Mass transfer via Roche-lobe overflow. 8 HMXBs 280 X-ray Binaries At least 15 micro- including 43 (15%) Radio 35 LMXBs quasars emitting Dermer XRBs VERITAS_NYC 28-29 May 2010 6 High Mass Microquasars

Paredes (2005)

P = 4.8 hr

GeV/TeV Emitter LS 5039: 26 Mo O6.5V, 39000 K, 7e38 erg/s Cyg X-3: Wolf-Rayet star V1521 Cyg

Cyg X-1: Blue supergiant, 31000 K, ~20-40 Mo, >40 Mo PSR 1259-63 47 ms Be X-ray binary 47 ms Be X-ray binary Porb=3.5 yr (not a microquasar)

Dermer VERITAS_NYC 28-29 May 2010 7 Low Mass Microquasars

Paredes (2005)

Dermer VERITAS_NYC 28-29 May 2010 8 Three eccentric binaries

MBH < 4 M~ or NS age < 2-3 Myr LS 5039 (HESS) LSI +61°303 (MAGIC) spectral brightening with flux 3.903 d et al. ’05 Albert et al. ‘06 Aharonian

Dermer VERITAS_NYC 28-29 May 2010 9 Models for high energy γ rays from γ-ray binaries

MICROQUASAR JET MODELS: Powered by accretion onto compact objet Blazar-microblazar analogy High mass stars provide wind (accretion energy) + photons (targets) Leptonic microquasar model: electrons in the jets are accelerated up to TeV energies Hadronic microquasar models Mildly relativistic outflows Confirming evidence: VHE emission from definite BHs (e.g Cyg X-1, V 4641, GRS 1915)

PULSAR WIND MODEL: Powered by rotational energy of neutron star

PSR B1259-63, LS 5039 & LSI +61 303 have compact objects with M < 4 Mo Time variability & X-ray spectrum of LSI +61 303 resemble those of young pulsars LS 5039, LSI have similar spectral cutoffs to pulsars LSI +61 303 is a Be star like PSR B1259-63 & all known Be/X-ray binary are NSs But does not satisfactorily fit the GeV & radio wavelength fluxes in LSI & LS 5039 Confirming evidence: Detection of pulsations in LS 5039 & LSI +61 303

ROTATING BLACK-HOLE WIND MODEL

Dermer VERITAS_NYC 28-29 May 2010 10 Leptonic Microquasar Model for LS 5039

RXTE

XMM

Aharonian et al. (2005)

Companion O7 Star (L ≅ 7×1038 ergs s-1) Optical stellar radiation strongly absorbs Leptonic Jet Model (as in blazars) TeV photons and provides a target for jet Synchrotron radio/optical/X-ray emission and electrons to be scattered to GeV energies thermal/nonthermal accretion disk and thermal Radio emission from jets reaches 10 AU stellar radiation) Compton-scattered origin of γ rays: Target photons from accretion disk and stellar radiation field

Dermer VERITAS_NYC 28-29 May 2010 11 Bosch-Ramon jet model fit to LS5039 pre-Fermi

Dermer VERITAS_NYC 28-29 May 2010 12 Spectral Energy Distribution + Components…(Paredes et al. 2006, A&A 451, 259).

Dermer VERITAS_NYC 28-29 May 2010 13 External Compton Scattering ECS with a dominant contribution from the companion star field

X-ray emitting jets (by Compton, not synchrotron): ➢ Cylindrical jet populated by relativistic particles emitting by IC processes. ➢ Injected 100 MeV e- interact via Thomson with stellar and disk photons.

➢ Applied to Cygnus X-1 and XTE J1118+480 ECS emission due to the (Georganopoulos, Aharonian & Kirk 2002, A&A 388, L25). companion star

ECS emission due to the accretion disc

ECS emission due to Cygnus X-1 XTE J1118+480 the accretion disc Dermer VERITAS_NYC 28-29 May 2010 14 γ Rays from Microquasars: Production and Attenuation

Phase φ = 0 (High mass star Compton Scattering in KN regime for TeV γ rays closest to observer): superior – Companion Star Temperature = 39000 K = 3.4 eV conjunction Orbital Modulation of Compton Scattered radiation d – Anisotropic stellar radiation field Böttcher and Dermer (2005) γγ Attenuation

(inf conj) φ = π

φ = 0 (sup conj)

Dermer VERITAS_NYC 28-29 May 2010 15 Spectral changes induced by γγ opacity

HESS data Aharonian et al. 2006

Dubus et al. (2008)

M. Böttcher (2007)

Dermer VERITAS_NYC 28-29 May 2010 16 Anisotropic Compton Scattering Calculations

Parameter study using broken power law electron distribution

How to make GeV spectrum with break at a few GeV?

Composite pulsar + shocked wind spectrum (Torres et al. 2010)

Scattering effects

Combined scattering and γγ + cascade calcultion

Dermer VERITAS_NYC 28-29 May 2010 17 Model Fit to the Multiwavelength Spectrum of LS 5039

Microquasar jet model

Fit assuming EGRET and HESS data are simultaneously measured SED

EGRET emission: high- energy extension of synchrotron spectrum

Combination of Compton Scattered Stellar Radiation and SSC for TeV

Dermer & Böttcher 2006

Dermer VERITAS_NYC 28-29 May 2010 18 Model Fit to the Multiwavelength Spectrum of LS 5039

Fit assuming that EGRET and HESS data are different between two epochs of measurement

In accord with variability expected from leptonic model

Predict orbital modulation of TeV γ-rays for inner jet model

Orbital modulation of GeV γ-rays for inner or extended jet model

Dermer VERITAS_NYC 28-29 May 2010 19 Flow evolution calculations

Scattering Calculations Dubus, Cerutti, & Henri (2008) KN Hardening effect: Dermer & Atoyan (2002) Moderski et al. (2006)

Dermer VERITAS_NYC 28-29 May 2010 20 Propagation of very high energy γ-rays inside massive binaries LS 5039 and LSI +61 303

Bednarek (2006) Bednarek and Giovanelli (2007)

Primary electrons and/or gamma-rays, injected at the distance z from the base of the jet, initiate an anisotropic IC e± pair cascade in the radiation field of the massive star. A part of the primary γ-rays and secondary cascade γ-rays escape from the binary system toward the observer.

The cascade processes occurring inside these binary systems significantly reduce the γ-ray opacity obtained in other works by simple calculations of the escape of γ-rays The maximum in TeV γ-ray light curve predicted from the radiation fields of the massive stars by the propagation effects in LSI +61 303 should occur after periastron passage (as has been observed).

Dermer VERITAS_NYC 28-29 May 2010 21 Hadronic jet models for microquasars

Hadronic models (only) for gamma γ-ray emission:

➢ Conical jet 1014 eV protons interacting with strong stellar wind protons, assuming efficient wind proton diffusion inside the jet. ➢ Protons are injected in the base of the jet and evolve adiabaticaly. ➢ Applied to explain gamma-ray emission from high mass microquasars (Romero et al. 2003, A&A 410, L1). ¾ The γ-ray emission arises from the decay of neutral pions created in the inelastic collisions between relativistic protons ejected by the compact object and the ions in the stellar wind.

Dermer VERITAS_NYC 28-29 May 2010 22 Model for windy high-mass stellar companion and multi-TeV protons in the jet. Spherically symmetric wind and circular orbit Romero,Torres, Kaufman, Mirabel 2003, A&A 410, L1

Secondary nuclear production (Aharonian & Atoyan 1996, Space Sci. Rev. 75, 357). Photopion production for UHECRs

Dermer VERITAS_NYC 28-29 May 2010 23 An application to LSI+61303 Romero, Christiansen & Orellana 2005, ApJ 632, 1093

¾ γ-ray emission originates in pp interactions between relativistic protons in the jet and cold protons from the wind. ¾ Opacity effects on the γ-rays introduced by the different photons fields

Blue: luminosity corrected by absorption in the stellar and disk photon fields

Dermer VERITAS_NYC 28-29 May 2010 24 • Models from radio to VHE: ➢Released 1014 eV protons from the jet that diffuse through and interact with the ISM. ➢Computed the broadband spectrum of the emission coming out from the pp primary interactions (γ-rays produced by neutral pion decay) as well as the emission (synchrotron, bremsstrahlung and IC scattering) produced by the secondary particles produced by charged pion-decay. ➢All the respective energy losses have been taken unto account. ➢Applied to impulsive and permanent microquasar ejections.

1) 100 yr 2) 1000 yr, 3) 10000 yr

dMQ/cloud=10pc 5 Mcloud=10 Msun 37 Ljet=10 erg/s

Bosch-Ramon et al. 2005 Romero et al. (2010)

Dermer VERITAS_NYC 28-29 May 2010 25 Jet formation, evolution and termination

Particle acceleration and transport

Radiative Processes

Cascades

Rev: Bosch-Ramon & Khangulyan 2009

Pulsar Wind Model

Dermer VERITAS_NYC 28-29 May 2010 26 LSI +61 303 Interaction of the relativistic wind from a young pulsar with the wind from its stellar companion

Stellar wind is equatorial Periastron: full black lines Dubus 2006 Apastron: dashed black lines

Rotation powered pulsar

Sierpowska-Bartosik & Torres 2008 PSR 1259-63: next periastron passage: ~Christmas 2010

Dermer VERITAS_NYC 28-29 May 2010 27 Cygnus X-1

One of best Galactic black hole source (~10 Mo) γ-ray black hole (?) – 5 pc bow shock, 50 % unseen energy Flaring MAGIC emission Hadronic model (Romero et al. 2010)

Albert et al. ‘07

SS433 Jet/ISM interactions Dubner et al. 1998, ApJ

Gallo et al. ‘05

Dermer VERITAS_NYC 28-29 May 2010 28 Isolated Black Holes

Number of black holes in the Galaxy: IMF vs. GRB Bondi-Hoyle accretion onto isolated black hole Model for low- and high-latitude unidentified sources Mechanism to form γ rays?

Accreting isolated black holes and the unidentified EGRET sources, AIP Conference Proceedings, Dermer

http://adsabs.harvard.edu/abs/1997AIPC..410.1275D

See work by Punsly, Romero,

Dermer VERITAS_NYC 28-29 May 2010 29 Galactic Center Region

6 Mass within 0.015 pc ≈ 4×10 M☼

Nearby bright EGRET unID source

Nonvariable HESS point-source + ridge emission

Fermi results: TBA

R. Genzel et al. (2004) Dermer VERITAS_NYC 28-29 May 2010 30 Black Hole Plerion Concept

(aka Black-Hole Wind Nebula) Electrons and protons accelerated by first-order (shock) Fermi acceleration.

Particle escape by convective outflow in advection- Electrons emit X-ray synchrotron radiation to form dominated inflow-outflow source (ADIOS) extension quiescent X-ray emission (Blandford & Begelman 1999) of ADAF model. and Compton scatter ADAF emission Assume a wind power 1013 Hz emission from cold dust ring around Sgr 37 −1 A* Lwind =10 L37 ergs s

With speed vwind≈c/2 directed into solid angle Ω≈1 sr, Wind terminates at a subrelativistic shock at found by equating thermal gas pressure with energy density of wind R ≅ 3×1016 L1/ 2 Ω−1/ 2cm shock 37 w

Neutron Star Plerion: Crab Nebula Dermer VERITAS_NYC 28-29 May 2010 31 Radio/sub-mm, quiescent X-ray, TeV emission

Atoyan & Dermer (2004)

Dermer VERITAS_NYC 28-29 May 2010 32 Summary ¾ γ-ray binaries are high-mass X-ray binaries: (pulsar-star or rotating black hole) colliding wind or black-hole microquasars

¾ Leptonic and hadronic model are highly geometrical, with the principal photon source being the directional high-mass star photon spectrum (accretion disk for LMXBs)

¾ LSI +61 303 probably pulsar/high mass stellar binary; open question for LS 5039 and Cyg X-3; black hole for Cyg X-1

¾ Black-hole wind model using BZ effect for a pulsar-wind like system with black hole

¾ Plerionic emission from black hole outflows

¾ Predictions for GeV/TeV emission from LMXBs: the next high-energy source class?

Dermer VERITAS_NYC 28-29 May 2010 33 Back-up Slides

Dermer VERITAS_NYC 28-29 May 2010 34 Synchrotron Models for Microquasars including LMXBs

Leptonic models:

SSC Atoyan & Aharonian 1999, MNRAS 302, 253 Latham et al. 2005, AIP CP745, 323

EC Kaufman Bernadó et al. 2002, A&A 385, L10 Georganopoulos et al. 2002, A&A 388, L25

SSC+EC Bosch-Ramon et al. 2004 A&A 417, 1075 Synchrotron jet emission Markoff et al. 2003, A&A 397, 645

Dermer VERITAS_NYC 28-29 May 2010 35 Models of adiabatically expanding synchrotron radiation-emitting conical jets may explain some of the characteristics of radio emission from X-ray binaries. Hjellming & Johnston 1988, ApJ 328, 60

Van der Laan (1966) model • Expanding cloud with continuous injection of electrons. • Production of X-rays by inverse Compton scattering of external photons and synchrotron- self-Compton scattering • Radiative and adiabatic cooling

Applied to SS433 (Band & Grindlay 1986, ApJ 311, 595)

Cyg X-1 Cyg X-3 quiesc. LSI+61303

Dermer VERITAS_NYC 28-29 May 2010 36 Particle injection into twin jets • Cyg X-3 exhibits flaring to levels of 20 Jy or more • In 1972 was first “caught” flaring above 20 Jy. These events are amongst the best-known examples of observed expanding synchrotron-emitting sources (21 papers in Nature Phys. Sci. 239, No. 95 (1972))

• Modelling Cyg X-3 radio outbursts: particle injection into twin jets Martí et al. 1992, A&A 258,309

Martí et al. 2001, A&A 375, 476

β = 0.48 , θ =73°

VLA, 5 GHz

Dermer VERITAS_NYC 28-29 May 2010 37 Synchrotron jet emission

X-ray synchrotron emitting jets: ➢ Conical jet populated by relativistic particles emitting by synchrotron processes. ➢ Particle acceleration balanced by adiabatic and radiative losses in the jet “base”. Truncated accretion disk ÎWeak disk emission Î Low external photon density ➢ Applied, e.g., to XTE J1118+480 (Markoff, Falcke & Fender 2001, A&A).

XTE J1118+480

Dermer VERITAS_NYC 28-29 May 2010 38 Leptonic high energy models

Synchrotron self Compton model

Non-thermal flares GRS1915+105 (Atoyan & Rodríguez et al. Aharonian 1999, MNRAS 302, 253) 1995, ApJS 101, 173 ¾ Flares are caused by synchrotron radiation of relativistic e− suffering radiative, adiabatic and energy- dependent escape losses in fast-expanding plasmoids (radio clouds) ¾ Continuous supply or in-situ acceleration of radio e−

BATSE 0.05 G ¾ Radio data gives basic parameter characterizing expanding plasmoids, IR 0.1G the e− may be accelerated up to TeV energies, and the fluxes of synchrotron sub-mm 0.2 G radiation could then extend beyond the radio GRS 1915+105 X-ray region and the fluxes of the IC γ- rays to HE and VHE.

Compton scattering or synchrotron emission from jets could dominate the high-energy emission above ~MeV Atoyan & Aharonian 1999, MNRAS 302, 253, and

2001 Dermer VERITAS_NYC 28-29 May 2010 39