Gamma- ray emission from Microquasars

Gamma- ray emission from Microquasars S. Saba5ni (G. Piano) on behalf of the AGILE Team

AGILE (in orbit since April 23, 2007) all sky map GRS 1915+105 Galactic Centre GRO 1655-40 Cyg X-3 Cyg X-1 SS 433 GRS 1758-258 2- years exposure - ray sky (E > 100 MeV) 2007, July 2009 June 2 S. Saba&ni - Gamma- ray emission from Microquasars

AGILE (in orbit since April 23, 2007) all sky map Gamma- ray emission is rare or undetectable in microquasars Θ (degrees) β Γ L X /L E γ/tev Cyg X-1 GRS 1915+105 30?? Galactic? Centre 0.1-1 YES Cyg X-3 < 14 > 0.8 > 1.6 0.1-1 YES GRO 1655-40 SS 433 80 0.26 1.03 0.01 no GRS 1915+105 70 0.92 2.5 0.1-1 no Cyg X-3 SS 433 GRO J1655-40 > 70 GRS 0.9 1758-2582.5 1 no Cyg X-1 GRS 1758-258? 0.1-1 no XTE J1550-564 60-70 > 0.8 1.5 0.1-1 no Sco X-1 > 70 > 0.8 > 1.6 0.1-1 no LS I 61 303??? 10-4 yes 2- years exposure - ray sky (E > 100 MeV) 2007, July 2009 June 3 LS 5039 < 80 > 0.2? 10-4 yes S. Saba&ni - Gamma- ray emission from Microquasars

Microquasars in the Cygnus region: AGILE-GRID INTENSITY MAP (100 MeV-10 GeV) November 2007 July 2009, ~275 days, ~11 Ms net exposure time 2 microquasars S. Saba&ni - Gamma- ray emission from Microquasars

Compact Object Cygnus X- 1 BH, M 4-15 M Cygnus X- 3 Range from a Neutron Star of 1.4 M to a Black Hole of a mass of up to 10 M Period 5.6 days, orb. r. ~ 3.4 x 10 12 cm 4.8 h, orb. r. ~ 3 x 10 11 cm Companion O9.7 Supergiant, L ~ 10 39 erg/s Wolf Rayet, L ~ 10 39 erg/s Companion wind ~ 10-6 M /yr, v ~ 2000 km/s ~ 10-5 M /y, v ~ 1000 km/s Cygnus X- 3 is unique in orbital separa5on and luminosity of the companion star - > different processes are expected to dominate in the two systems S. Saba&ni - Gamma- ray emission from Microquasars 5

Typical X- ray spectra (before the AGILE/Fermi era) Cygnus X-1 Cygnus X-3 γ? ( 2008 al., (Zdziarski et al. 2002) (Szostek et

Typical X- ray spectra (before the AGILE/Fermi era) Cygnus X-1 Cygnus X-3 γ? ( 2008 al., (Zdziarski et al. 2002) (Szostek et Comptoniza&on of soh thermal photons from disk by a hybrid popula&on of electrons (thermal + non- thermal) in the corona. 2 main X- ray spectral states: Sod thermal emission ( BB ) from disk + Comptoniza&on by cold thermal electrons (SoH Excess) + Comptoniza&on by non- thermal high- energy electrons (power- law tail) Hard Comptonized emission by hot quasi- thermal popula&on of electrons S. Saba&ni - Gamma- ray emission from Microquasars

CYGNUS X- 3 S. Saba&ni - Gamma- ray emission from Microquasars 8

CYGNUS X- 3 gamma- ray flares Tavani et al. Nature 2009

γ- ray ac5vity detected by AGILE (November 2007 July 2009) in the context of the mul5wavelength emission radio soft X-rays hard X-rays γ-rays state S. Saba&ni - Gamma- ray emission from Microquasars 10

γ- ray ac5vity detected by AGILE (November 2007 July 2009) in the context of the mul5wavelength emission radio soft X-rays hard X-rays γ-rays state S. Saba&ni - Gamma- ray emission from Microquasars 11

γ- ray ac5vity detected by Fermi- LAT 11 Oct 20 Dec 2008 AGILE-GRID (Piano et al.,2012) Fermi- LAT: γ- ray ac&ve periods 4- day light curve (Abdo et al., 2009, Science) 8 Jun 2 Aug 2009 S. Saba&ni - Gamma- ray emission from Microquasars 12

By integra&ng the 7 γ- ray flares: Cygnus X- 3 γ- ray spectrum (E 100 MeV) Γ = 2.0 ± 0.2 Γ = 2.70 ± 0.05 (stat) ± 0.20 (syst) 6.7σ pre- trial 5.5σ post- trial (l,b) = (79.7, 0.9) ± 0.4 (stat.) ± 0.1 (syst.), F = (158 ± 29) x 10-8 ph cm - 2 s - 1 AGILE-GRID: 7 flares Fermi-LAT: 2 active windows (11 October 20 December 2008) (8 June 2 August 2009) [F steady = (14 ± 3) x 10-8 ph cm - 2 s - 1 ] S. Saba&ni - Gamma- ray emission from Microquasars

By integra&ng the 7 γ- ray flares: Cygnus X- 3 γ- ray spectrum (E 100 MeV) Γ = 2.0 ± 0.2 Γ = 2.70 ± 0.05 (stat) ± 0.20 (syst) 6.7σ pre- trial 5.5σ post- trial (l,b) = (79.7, 0.9) ± 0.4 (stat.) ± 0.1 (syst.), F = (158 ± 29) x 10-8 ph cm - 2 s - 1 [F steady = (14 ± 3) x 10-8 ph cm - 2 s - 1 ] AGILE-GRID: 7 flares Fermi-LAT: 2 active windows (11 October 20 December 2008) (8 June 2 August 2009) AGILE-GRID flaring : [158 ± 29] 10-8 ph cm -2 s -1 Fermi-LAT active : [119 ± 6 (stat) ± 37 (syst)] 10-8 ph cm -2 s -1 S. Saba&ni - Gamma- ray emission from Microquasars

By integra&ng the 7 γ- ray flares: Cygnus X- 3 γ- ray spectrum (E 100 MeV) Γ = 2.0 ± 0.2 Γ = 2.70 ± 0.05 (stat) ± 0.20 (syst) 6.7σ pre- trial 5.5σ post- trial (l,b) = (79.7, 0.9) ± 0.4 (stat.) ± 0.1 (syst.), F = (158 ± 29) x 10-8 ph cm - 2 s - 1 AGILE-GRID: 7 flares Fermi-LAT: 2 active windows (11 October 20 December 2008) (8 June 2 August 2009) [F steady = (14 ± 3) x 10-8 ph cm - 2 s - 1 ] Data for the modeling of the spectrum: o AGILE γ- ray spectrum [50 MeV 3 GeV] o typical X- ray spectrum of the quenched state HypersoH Spectrum (Koljonen et al., 2010) o (MAGIC ULs during soh spectral state) S. Saba&ni - Gamma- ray emission from Microquasars

γ-ray emission from Cygnus X-3 A LEPTONIC model: corona evacua&on ( HypersoH State) injec&on of a spherical plasmoid of rela&vis&c electrons/positrons scagering off soh photons from both the disk and the WR star - > gamma- rays from IC processes in the jet Star: Disk: L ~ 10 39 erg/s T bb ~ 1.3 kev Spherical plasmoid: r ~ 3 10 10 cm Inclina&on: i = 14 S. Saba&ni - Gamma- ray emission from Microquasars

Cygnus X- 3 mul5- wavelength spectrum 2 models Geometry of the interac&on: H ~ 3 10 10 cm ~ 10-1 d (Piano et al., 2012) Hypersoft state (Koljonen et al. (2010)) (R star- blob distance) R ~ d ~ 3 10 11 cm (plasmoid close to the disk) electron density ~ 3 10 9 cm - 3 Geometry of the interac&on: H ~ 3 10 12 cm ~ 10 d (R star- blob distance) R ~ H ~ 3 10 12 cm (far away plasmoid ) electron density ~ 1.5 10 11 cm - 3 Hypersoft state (Koljonen et al. (2010)) S. Saba&ni - Gamma- ray emission from Microquasars

A HADRONIC model: injec5on of mildly rela5vis5c protons interac5on with the hadronic gas of the WR strong wind along a cylindrical column of maqer (radius R~ 3 10 10 cm, height H ~ 3 10 12 cm) inelas5c scaqerings: p + p π 0 + ; π 0 γ + γ S. Saba&ni Giovanni - Gamma- ray Piano emission from Microquasars

A HADRONIC model: Stellar wind: Geometry of the interaction: jet protons interact with the hadronic matter of the wind along a cylinder: proton distribution: power-law with high-energy cut-off homogeneous (not clumpy) R ~ 3 10 10 cm H ~ 3 10 12 cm i = 14 S. Saba&ni Giovanni - Gamma- ray Piano emission from Microquasars

A hadronic model Results from the modeling: (Piano et al., 2012) o Disk luminosity of the Hypersoft state (L HYS ~10 38 erg s -1 ) Giovanni Piano o Eddington accretion limit (L Edd ~10 39 erg s -1 ) [M x = 10 M ] S. Saba&ni - Gamma- ray emission from Microquasars

A hadronic model Results from the modeling: (Piano et al., 2012) o Disk luminosity of the Hypersoft state (L HYS ~10 38 erg s -1 ) Giovanni Piano o Eddington accretion limit (L Edd ~10 39 erg s -1 ) [M x = 10 M ] S. Saba&ni - Gamma- ray emission from Microquasars

Phenomenology of the transient γ- ray ac5vity: o when? during soh states, a few days before strong radio outbursts the system is moving into or out of the quenched state ( spectral signature of the γ- ray emission in Cygnus X- 3) o where? in the jet IC γ- rays (by rela&vis&c leptons) γ- rays from π 0 - decays (by rela&vis&c protons) (evidence of extreme par&cle accelera&on) S. Saba&ni - Gamma- ray emission from Microquasars

Emission models: o Leptonic scenario spectral link with hard X- ray emission lowest part of the jet [up to ~10 10 cm] 100 kev farthest part of the jet [above ~10 10 cm] >100 MeV low jet kine&c power temporal link with major radio flares (electrons are the main emigers) consistent with the γ- ray modula&on (Fermi- LAT) (Dubus et al., 2010, Zdziarski et al., 2012) o Hadronic scenario physically reasonable consistent with the spectral shape detected by AGILE energe&cs: sub- Eddington jet kine&c power S. Saba&ni - Gamma- ray emission from Microquasars

CYGNUS X- 1 S. Saba&ni - Gamma- ray emission from Microquasars 24

(Zdziarski et al. 2002) S. Saba&ni - Gamma- ray emission from Microquasars 25

(Zdziarski et al. 2002) S. Saba&ni - Gamma- ray emission from Microquasars 26

AGILE observing periods S. Saba&ni - Gamma- ray emission from Microquasars 27

Cyg X- 1: AGILE DEEP INTEGRATIONS HARD STATE Sabatini et al 2010 2σ UL: F γ < 3 x 10-8 ph/cm 2 /s S. Saba&ni - Gamma- ray emission from Microquasars 28

The jet contribution is contrained by the average gammaray emission S. Saba&ni - Gamma- ray emission from Microquasars 29

AGILE observing periods sod state BAT/Swift hard X-rays MAXI X-rays AMI-LA radio, 10 GHz

AGILE observing periods sod state BAT/Swift hard X-rays MAXI X-rays AMI-LA radio, 10 GHz

Cyg X- 1: AGILE DEEP INTEGRATIONS HARD STATE Sabatini et al 2010 2σ UL: F γ < 3 x 10-8 ph/cm 2 /s SOFT STATE Sabatini et al 2013 S. Saba&ni - Gamma- ray emission from Microquasars 2σ UL: F γ < 20 x 10-8 ph/cm 2 /s 32

Comptoniza5on models for Cyg X- 1 Sabatini et al, 2013 AGILE combined with broad-band data give important constraints on the model parameters. E.g. the soft Compactness parameter (l = Lσ T /Rm e c 3 ) has to be l s 10 S. Saba&ni - Gamma- ray emission from Microquasars

Cyg X- 1 TRANSIENT ACTIVITY in GAMMA- RAYS S. Saba&ni - Gamma- ray emission from Microquasars 34

FAST FLARING ACTIVITY VHE (>100GeV) flare las5ng ~1hr (MAGIC; Albert 2007) An intense peak in hard X- rays followed it (INTEGRAL; Malzac 2008) Transient rela5vis5c RADIO jet ~20min (MERLIN; Fender 2006) S. Saba&ni - Gamma- ray emission from Microquasars 35

GAMMA- RAY FLARING EPISODES HARD STATE 1- day dura5on (or less) SIGNIFICANCE: 5.3σ F γ = 232±66 x 10-8 ph/cm 2 /s (Saba&ni et al. 2010) S. Saba&ni - Gamma- ray emission from Microquasars 36 36

GAMMA- RAY FLARING EPISODES HARD STATE 1- day dura5on (or less) SIGNIFICANCE: 5.3σ F γ = 232±66 x 10-8 ph/cm 2 /s HARD STATE (Saba&ni et al. 2010) S. Saba&ni - Gamma- ray emission from Microquasars 37

GAMMA- RAY FLARING EPISODES HARD STATE 1- day dura5on (or less) SIGNIFICANCE: 5.3σ F γ = 232±66 x 10-8 ph/cm 2 /s (Saba&ni et al. 2010) SOFT STATE 2- days dura5on (or less) SIGNIFICANCE: 3σ F γ = 145±78 x 10-8 ph/cm 2 /s (Saba&ni et al. 2013 ) S. Saba&ni - Gamma- ray emission from Microquasars 38 38

GAMMA- RAY FLARING EPISODES SOFT STATE HARD STATE 1- day dura5on (or less) SIGNIFICANCE: 5.3σ F γ = 232±66 x 10-8 ph/cm2/s (Saba&ni et al. 2010) SOFT STATE 2- days dura5on (or less) SIGNIFICANCE: 3σ F γ = 145±78 x 10-8 ph/cm2/s (Saba&ni et al. 2013 ) S. Saba&ni - Gamma- ray emission from Microquasars 39 39

GAMMA- RAY FLARING EPISODES SOFT STATE HARD STATE 1- day dura5on (or less) SIGNIFICANCE: 5.3σ F γ = 232±66 x 10-8 ph/cm2/s (Saba&ni et al. 2010) SOFT STATE 2- days dura5on (or less) SIGNIFICANCE: 3σ F γ = 145±78 x 10-8 ph/cm2/s (Saba&ni et al. 2013 ) S. Saba&ni - Gamma- ray emission from Microquasars 40 40

A. BODAGHEE Fermi Symp 2012 S. Saba&ni - Gamma- ray emission from Microquasars 41

AGILE candidate flare: 30 June 2 July 2010 Possible viola&ons of comptoniza&on model during gamma- ray flares SOFT STATE FLARE SOFT STATE 2- days dura5on (or less) SIGNIFICANCE: 3σ F γ = 145±78 x 10-8 ph/cm 2 /s (Saba&ni et al. 2013 ) S. Saba&ni - Gamma- ray emission from Microquasars 42 42

Modelling the jet component ONE ZONE MODEL SSC only S. Saba&ni - Gamma- ray emission from Microquasars 43

Possible modelling of the jet component broken power- law (gamma_b=1800, gamm_max=gamma_b) ~ 2 K=10^9cm^-3 B=2e3 Gauss r=10^9cm. Not univocally determined (other parameters are allowed, eg =1.5 and r=5x10^9 with a smaller K ) S. Saba&ni - Gamma- ray emission from Microquasars 44

CONCLUSIONS II Gamma- ray emission is rare or undetectable in microquasars Θ (degrees) β Γ L X /L E γ/tev Cyg X-1 30??? 0.1-1 YES Cyg X-3 < 14 > 0.8 > 1.6 0.1-1 YES SS 433 80 0.26 1.03 0.01 no GRS 1915+105 70 0.92 2.5 0.1-1 no GRO J1655-40 > 70 0.9 2.5 1 no GRS 1758-258? 0.1-1 no XTE J1550-564 60-70 > 0.8 1.5 0.1-1 no Sco X-1 > 70 > 0.8 > 1.6 0.1-1 no LS I 61 303??? 10-4 yes LS 5039 < 80 > 0.2? 10-4 yes S. Saba&ni - Gamma- ray emission from Microquasars 45

CONCLUSIONS II Gamma- ray emission is rare or undetectable in microquasars Cyg X- 1 UL puts important constraints to - Comptoniza5on models (confirmed at large) - the jet component. S. Saba&ni - Gamma- ray emission from Microquasars 46

CONCLUSIONS II Gamma- ray emission is rare or undetectable in microquasars Cyg X- 1 UL puts important constraints to - Comptoniza5on models (confirmed at large) - jet component Hadronic and leptonic models for the gamma- ray emission in Cygnus X- 3 s5ll permiqed S. Saba&ni - Gamma- ray emission from Microquasars 47

CONCLUSIONS II Gamma- ray emission is rare or undetectable in microquasars Cyg X- 1 UL puts important constraints to Comptoniza5on models (confirmed at large) and jet component Hadronic and leptonic models for the gamma- ray emission in Cygnus X- 3 s5ll allowed Contribu5on of the jet can be important to account for gamma- ray flares (Cyg X- 3 and possibly Cyg X- 1) CYG X- 1 CYG X- 3 S. Saba&ni - Gamma- ray emission from Microquasars 48

CONCLUSIONS II Gamma- ray emission is rare or undetectable in microquasars Cyg X- 1 UL puts important constraints to Comptoniza5on models (confirmed at large) Hadronic and leptonic models for the gamma- ray emission in Cygnus X- 3 s5ll allowed THANKS FOR YOUR ATTENTION Contribu5on of the jet can be important to account for gamma- ray flares (Cyg X- 3 and possibly Cyg X- 1) CYG X- 1 CYG X- 3 S. Saba&ni - Gamma- ray emission from Microquasars 49