Presentation on theme: "Raffaella Margutti Harvard – Institute for Theory and Computation On behalf of the Harvard SN forensic team Kyoto2013 What happens when jets barely break."— Presentation transcript:
Raffaella Margutti Harvard – Institute for Theory and Computation On behalf of the Harvard SN forensic team Kyoto2013 What happens when jets barely break out of a star?
Type Ic SN core H envelope MASSIVE STAR WINDS CE Why only ~ few % of type Ibc SN harbors a CE?1 How does the CE manifest its presence ? 2
How does the central engine manifest its presence? Temporal Variability Prompt gamma-ray emission (e.g. Morsony+10) X-ray flares (Margutti+13; Chincarini+10;Bernardini+12; Margutti+11a; Margutti+11b ) X-ray plateau Magnetar (e.g. Dall’Osso+10) or accretion (e.g. Kumar+08) Margutti et al.,2013 ApJ 778 18, (arXiv:1308.1687) Energy partitioning + Late-time X-ray excess GRB100316D/SN2010bh
Kyoto 2013 -->Continuum Less energetic than GRBs (local universe) Mildly relativistic Less collimated than GRBs 10 times more common than GRBs Collimation Their Ek profile still requires a CE
Take-away list: 1. Kyoto 2013 The key difference between an ordinary explosion and an engine- powered explosion is the way the energy budget is PARTITIONED. There is a continuum of properties, that bridges the gap between ultra- relativistic, collimated explosions and ordinary SNe, populated by: Sub-E GRBs and relativistic SNe 2.
Kyoto 2013 do we care so much about these intermediate explosions WHY ? GRB100316D/SN2010bh Margutti et al.,2013 ApJ 778 18
100316D/2010bh MILD decay + Extremely SOFT emission Central engine Faster blob Slower blob Collision EXTERNAL SHOCK Pre Burst Prompt Emission Ambient medium interaction Afterglow STANDARD GRB MODEL Synchrotron Engine ON Engine OFF
UCSC 2013 Synchrotron emission Fireball Dynamics Not synchrotron GRBs
UCSC 2013 100316D/ 2010bh Synchrotron Radio X-rays SED, t=36 days Radio X-rays
Inverse Compton emission 100316D/2010bh 10 days 37 days Accretion on BH Magnetar spin-down CE …an X-ray excess… What is the origin? t -0.8 “modified” fall-back scenario” ~10^52 erg Rapidly rotating!! (ms!)
Take-away list: 1. Kyoto 2013 The key difference between an ordinary explosion and an engine- powered explosion is the way the energy budget is PARTITIONED. There is a continuum of properties, that bridges the gap between ultra- relativistic, collimated explosions and ordinary SNe, populated by: Sub-E GRBs and relativistic SNe 2. Sub-energetic GRBs reveal the emission of the CE at late times, either in the form of a rapidly rotating magnetar or a BH (in a non-standard fall- back accretion scenario) 3.
Kyoto 2013 The big picture: H-stripped explosions Ordinary SNe Ibc NO Engine, NO JET GRBs Engine Fully developed jet Sub-E GRBs Engine Weak jet We can study the engine with late-time radio and X-rays Jet CE Jet CE
OPTICAL RADIO synchrotron Wellons +12 Soderberg+04, +06,+10 F ν,peak (t) ν peak (t) -5/2 -(p-1)/2 SN shock interaction with the medium Drout +11 LC width τ≈(Mej 3 /Ek) 1/4 V phot ≈Ek/Mej
Gamma-Ray Bursts Log(Time) Log(Flux) γ-rays ~30 s ~10^51 erg X-rays Optical Radio ~hours Central engine Faster blob Slower blobCollision Ambient medium interaction INTERNAL SHOCK EXTERNAL SHOCK AfterglowAfterglow Pre Burst Prompt Emission JET
Log(Time) Log (Flux) t break1 (300 s) t break2 (10^4 s) t -3 t -1 t -2 PROMPT AFTERGLOW A typical GRBExplosion: Black Hole (?) SN bump ~10 days
UCSC 2013 HIGH expansion velocity! 30000-40000 km/s vs. 10000 km/s Modjaz 2006 GRB060218 GRB980425 Sanders 2012 Photosperic Velocity (10 3 km/s) SN/GRB BL-SN Ibc SN2010ay SNe associated w. GRBs NO Hydrogen FAST
UCSC 2013 SN1994I SN2002ap GRB/SNe “Standard”, envelope stripped SN IbcHydrogen-poor Super Luminous SNe (M<-21) (e.g. Gal-Yam 2012) 7x10 43 erg/s Broad-lined + large Ek + large Ni mass = Very powerful / energetic explosions