Mass-loading and non-thermal emission from AGN jets interacting with stellar populations NÚRIA TORRES-ALBÀ (1)* *ntorres@fqa.ub.edu IN COLL. W ITH V. BOSCH- RAMON (1) AND F. L. VIEYRO (1,2) 1 Departament de Física Quàntica i Astrofísica, Institut de Ciències del Cosmos (ICC), Universitat de Barcelona 2 Instituto Argentino de Radioastronomía (IAR), CCT La Plata, Argentina
JETS AND THEIR GALAXY HOSTS Black hole accretes material from inner region of galaxy host Production of collimated relativistic outflows, or jets Jet propagates through rich environment, which can lead to deceleration (e.g. Perucho et al. 2014) Jet and wind heat the gas and stop star formation. AGN feedback (e.g. Fabian 2012) 1
JETS AND OBSTACLES BLR clouds Dar & Laor (1997) Araudo et al (2010) NLR clouds Steffen (1997) Stars Bednarek & Protheroe (1997) Barkov et al (2010) Araudo et al (2013) Bosch-Ramon (2015) Wykes et al (2015) Vieyro et al (2017) Perucho et al (2014) Globular clusters Bednarek & Banasinski (2015) Image credit: Brooks/Cole Thomson 2
JET DECELERATION FR I FR II Fanaroff & Railey (1974) 3
JET DECELERATION FR I Jet deceleration Mixing in a turbulent shear layer De Young (1986, 1993) Bicknell (1994) Wang et al.( 2009) Mass loading by stellar winds Komissarov (1994) Bowman et al. (1996) Perucho et al. (2014) Vieyro et al. (2017) Recollimation shocks Perucho & Martí (2007) 4
GAMMA-RAY EMISSION: STARS Stellar wind and jet collide, creating a double bow-shock. Stagnation point: Wind and jet ram pressures are equal. Particles are accelerated in the shock, leading to emission. Araudo et al. (2013) 5
JETS AND STARS: PERSISTENT EMISSION Stellar population with high massloss rates Red Giants in elliptical galaxies OB stars in starburst galaxies Interaction with the jet in steady state: Vieyro et al. 2017 large number of stars always within the jet Interaction with the jet at the moment of penetration: Stellar wind bubbles are carried into the jet as the stars penetrate 6
Red Giants 7
8
P ISM v orb P orb P lat A bubble of stellar material is formed up to the point where P ext = P CD sw 9
Part of the material is lost in the Contact Discontinuity (CD) v orb CD P jet Part of the bubble survives and enters the jet The less dense layers are peeled away (for r in which C s (r)>v orb ) 10
A bubble of smaller radius manages to enter the jet (C s (r)<v orb ) v orb The pressure equilibrium after entering is P jet =P sw CD P jet The most external layers, with lower P sw, are lost within the jet 11
Bubble State The bubble inflates and quickly accelerates upstream A shock is formed, and non-thermal emission is generated CD v orb Steady State The most external layers, with lower P w, are lost within the jet 12
Bubble Radius R (pc) 13
PRESCRIPTIONS: RED GIANTS Vieyro et al. 2017 14
PRESCRIPTIONS: STELLAR POPULATION Galaxy properties: Galaxy stellar mass Salpeter law Age of galaxy N * and M * of Red Giants (Gebhardt & Thomas, 2009) We take reference values from M87 Stellar distribution: nn zz 1 zz Jet properties: Jet facing the observer LL jj = 10 44 erg/s, Γ = 10, θθ = 0.1 Penetration rate: PPPP nn vv oooooo rr jj (Khangulyan et al. 2013) (HTS, NASA (STScI/AURA)) 15
MASS LOAD Mass from the bubbles is loaded in the CD and inside the jet Mass-loss rate from stars is loaded in the jet during steady state Jet MM = LL jj /cc 2 Γ 16
LUMINOSITY Average Luminosity LL γγ,iiii 10 40 eeeeee/ss LL γγ,ssss 10 42 eeeeee/ss (BB = 0.1BB eeee ) Dominated by infrequent events of LL pppppppp,iiii 10 42 erg/s LL pppppppp,ssss 10 43 erg/s tt pppppppp 10 7 s PPPP 0.01 yr -1 17
CONCLUSIONS AND FUTURE WORK Dynamical effects on the jet are likely to be caused by steadystate interaction, but not through wind-bubble interaction. Gamma-ray emission caused by steady-state interaction is persistent, while wind bubbles would generate flares. Events in nearby AGN are potentially detectable We are working on jet mass-loading simulations Statistical estimation of the amount of sources that could be detectable 18