Giant Radio Pulses Radio Properties Mechanism High Energy Properties With Astrosat & LOFT

Giant Radio Pulses Flux density > M Jy T b > K! Highly variable polarisation Scales ~ 1 m Crab

Giant Radio Pulses Crab Mickaliger et al Giant pulses in different Radio frequencies are simultaneous GPs occur only at the normal pulse Phases MP and IP

Giant Radio Pulses First observed in the Crab pulsar - discovered through its giant pulses! Intense narrow pulses (~10 ns) Brightness Temp: upto 5 x 10^39 Random in occurrence, at certain pulse phases Pulse energy many times that of an average pulse One or more power-law distribution of pulse energies Highly polarizeded/variable

Giant Radio Pulses Crab Popov et al Karuppusamy et al. 2010

Giant Radio Pulses Crab Majid et al Pulse width up to 100  s 50-90% of total pulse Flux energy is in the Giant pulses

Giant Radio Pulses PSR B Kinkhabwala et al. 2000

Giant Radio Pulses PSR B Kinkhabwala et al. 2000

Giant Radio Pulses PSR B Soglasnov et al Width: < 15 ns T_B : 5 x 10^39 K Discharges in the polar cap region

Giant Radio Pulse: Mechanism Conversion of electrostatic turbulence in the pulsar magnetosphere by the mechanism of spatial collapse of nonlinear wave packets (Hankins et al.,2003) Electric discharge due to the magnetic reconnection of field lines connecting the opposite magnetic poles (Istmin Ya. N., 2004) Coherent curvature radiation of charged relativistic solitons associated with sparking discharge of the inner gap potential drop above the polar cap (Gil, J & Melikadze G., 2004) Induced Compton scattering of pulsar radiation off the particles of the plasma flow (Petrova S. A. 2004) Cyclotron line at the light cylinder during reconnection events (Lyutikov 2013)

(Knight et al. 2006) PSR J (Cusumano et al. 2003) PSR B Giant Pulses from MSPs Large magnetic field at the light cylinder Pulsed non-thermal X-ray emission X-ray emission at the same phase of GP RXTE BeppoSAX Radio Chandra kev GBT 850 MHz

(Shearer et al. 2003) Giant Pulses and High Energy emission: Crab Optical Flux enhancement: 3% Enhancement of electron positron plasma

(Strader et al. 2013) Giant Pulses and High Energy emission: Crab Optical Peak flux enhancement: 11% for Giant Pulses near the peak of the optical pulse, 3% otherwise Flux enhancement: 3% for Giant Pulses at the Main Pulse

(Bilous et al. 2012) Giant Pulses and High Energy emission: Crab Chandra HRC: keV Chandra HCR: keV Upper limit of flux enhancement in pulses with GPs: 10% for MP GPs and 30% for IP GPs Upper limit of flux enhancement during the GPs: 2 for MP GPs and 5 for IP GPs Due to changes in coherent radio emissiom

(Mikami et al. 2014) Giant Pulses and High Energy emission: Crab Suzaku HXD, keV and keV 1 σ upper limit of flux enhancement: 70%

(Bilous et al. 2011) Giant Pulses and High Energy emission: Crab Fermi: 100 MeV - 5 GeV 95% confidence upper limit of flux enhancement: 4 times for all GPs and 12 for IP GPs Due to changes in coherent radio emissiom and not due to enhanced particle density

Aliu et al Giant Pulses and High Energy emission: Crab Veritas: > 150 GeV Upper limit of flux enhancement: 5 times for pulses with GP Upper limit of flux enhancement: 2 times for 8s window around GP

Cusumano et al. 2003, Nicastro et al Giant Pulses and High Energy emission: X-ray emission is at the same phase as the Giant Pulses

Giant Pulses and High Energy emission S/N = sA*T/sqrt((sA+bA)T)= sqrt(AT)*s/sqrt(s+b) s T Chandra RXTE-PCA/ASTROSAT-LAXPC Crab: 10 hrs  bursts  0.2 sec, 400 photons,  100 photons (5 sigma)  sensitivity of 0.01 photon per GP  10^33 erg per GP in X-rays

Stability of X-ray Pulse Profiles: Crab ISRO HQ - 22 Apr 2014 Jain and Paul 2011