Walkthrough In collaboration with : WAM I. Grenier, A.K. Harding, - PowerPoint PPT Presentation

2 papers N. Renault-Tinacci Walkthrough In collaboration with : WAM I. Grenier, A.K. Harding, JM Casandjian, M.E. DeCesar, L. Guillemot, T.J. 1 April 2016 Johnson, Q. Remy, C. Venter.

• Why MSPs ? – Growing γ -ray pulsar class – Clues indicating same acceleration/radiation processes in MSPs as in young pulsar magnetospheres (similar γ -ray profiles, same B near the light cylinder) – More stable (but fainter) 1 st systematic phase-resolved spectral analysis of γ -ray MSPs • Where do the acceleration and γ -ray emission originate in the magnetosphere ? • Acceleration in thin screened gaps or in thick, pair- starved zones? • Which γ radiation processes involved? N. Renault- 2 Tinacci

J1311-3430 • Data selection : J1231-1411 2-peak 3-peak – Pass 7 Reprocessed Fermi-LAT data – 60 months (August 2008 – August 2013) Preliminary – 50 MeV < E phot < 170 GeV • Fixed-count binned lightcurves : – Tempo2 J0613-0200 J0102+4839 – photon selection ramp dome+peak • E phot > 200 MeV and θ phot < PSF 68% (E phot ) – separation of 4 MSP classes based on morphology – phase interval definition (Peak cores, wings, bridge,…) 2- Γ • Spectral analysis : – total emission and in phase intervals – iterative extraction of pulsed flux in energy bins (no need for an input spectral shape as in gtlike) E cut • Subsequent spectral characterization: – bivariate max-likelihood fit of PL Exponential E apex Cut-Off – local quadratic fit of SED apex energy – energy flux G >50MeV and luminosity L γ above 50 N. Renault- MeV 3 Tinacci

• 25 millisecond pulsars – bright – bright enough wrt background • Good sampling of the MSP population in – direction (l, b) – P & Pdot – energetics ( Ė , B LC , …) – geometry ( α Β , ζ view ) N. Renault- 4 Tinacci

PSR J1231-1411 Preliminary P1 Leading P3 • Measurable spectral P1 Core P2 Leading P1 Trailing P2 Core variations across Bridge P2 Trailing phase N. Renault- 5 Tinacci

Classification by Johnson et al. 2014 Preliminary Preliminary Preliminary • Softening with B LC (and Ė ) • Shift in E apex with Ė (and B LC ) – Γ constant with B LC rejected at >10 σ – Curvature testing (« pairwise slope statistics », Abrevaya et Jiang 2003) � P curv = 99,97 % N. Renault- 6 Tinacci

Classification by Johnson et al. 2014 Preliminary Preliminary Preliminary • Synchroton component from primary • Toy model of curv.-radiation spectra: pairs – primaries near the light cylinder with – too high energy γ rays for secondary various Γ max Lorentz factors pairs – curv. radius = R LC (Hirotani 2011) – for the SG (Harding et al. 2008) or OG – cannot reproduce the E apex vs Edot models (Takata et al. 2008) and Γ vs B LC trends • Smooth transition layer from E // ≠ 0 to – � Additional softer component N. Renault- required E // =0 � CR at a few hundred MeV 7 Tinacci - for the OG (Wang et al. 2010) or FIDO models (Kalapotharakos 2014)

Preliminary • Multi-peak pulsars : softening when radio and γ -ray peaks aligned ➔ Synchrotron component from pairs gaining pitch angle by cyclotron resonant absorption of co-located radio photons (Harding et al. 2008) ? Preliminary N. Renault- 8 Tinacci

• Maximum Lorentz factor estimation from E cut - for the total emission - assuming curv. radiation - with curv. radius = R LC (Hirotani 2011) Preliminary • Narrow Γ max distribution around 10 7 N. Renault- 9 Tinacci

Second Fermi-LAT Pulsar Catalog, Abdo et al. 2013 Preliminary L γ ∝ Ė 0.34±0.15 L γ ∝ Ė 1.34±0.13 • Total emission – Trend & dispersion consistent with 2PC • But : – Multi-peaks : L γ ∝ √Ė � screened thin gap near last closed B line dominates the output – Ramps : L γ ∝ Ė � unscreened thick region partially (?) filling the open magnetosphere N. Renault- 10 Tinacci

Preliminary screened unscreened L γ ∝ Ė 0.70±0.18 L γ ∝ Ė 0.41±0.17 L γ ∝ Ė 1.06±0.28 L γ ∝ Ė 0.5±0.12 screened unscreened L γ ∝ Ė 0.39±0.11 L γ ∝ Ė 0.97±0.22 L γ ∝ Ė -0.07±0.14 L γ ∝ Ė 0.28±0.17 � Change of screening properties across phase L γ ∝ Ė 0.63±0.26 • Marginal changes of E apex vs Ė across 11 phase N. Renault- Tinacci

Preliminary L γ ∝ Ė 0.97±0.14 L γ ∝ Ė 1.16±0.14 L γ ∝ Ė 1.35±0.11 Ramp pulsars L γ ∝ Ė 1.38±0.16 L γ ∝ Ė 1.16±0.16 • No evolution across phase � single emission region? • L γ ∝ Ė � unscreened gaps 12

• Need to re-think the classical picture of thin caustic gaps/wide unscreened regions – possibly co-existing in the magnetosphere and both contributing to the observed pulsed emission • MSP spectral sequence with Ė : – potential influence of radio emission – need for an additional soft screened screened radiation component harder • synchrotron radiation from confused primary pairs softer unscreened • and/or CR smooth transition layer softer in E // • The brighter the core, the higher unscreened the apex energy, the harder the softer SED • Softer emission and lower E apex outside the main peaks • Perspectives – confirm trends with 8 years of data and with larger MSP sample – same analyses for young pulsars to accompany 3PC N. Renault- 13 Tinacci

Thank you for your attention N. Renault- 14 Tinacci

BACK-UP N. Renault- 15 Tinacci

Effective IRFS for Ephemerides Fermi-LAT data components Peak spectra characterization Light-curve Photon phase Phase resolved 2 iterations analysis folding IRFs recalculation intervals 25°x25° square region template with previous step definition maps spectral results • Point source at pulsar position Data : • Nearby point/extended Phase averaged • 60 months sources spectral analysis • ISM • 50 MeV - 172 • Extragalactic background + GeV instrumental residuals • P7 reprocessed 10°-wide peripheral band Off-pulse definition Phase intervals 2 iterations IRFs recalculation spectral analysis with previous step Spectral analysis : spectral results • Binned maximum likelihood estimator 202 spectra with Poisson statistics Spectral (phase • Fit in each energy band independently characterization averaged & • Iteration � no analytical spectral shape resolved) assumption N. Renault- 16 Tinacci

PSR J1231-1411 P1 Leading Peak 1 Core 2- Γ P1 Core Peak 2 Core P1 Trailing E apex Preliminary • Photon index, Γ � primary particle P2 Leading distribution, cascade development and/or P2 Core P2 Trailing photon pile-up in phase • Apex Energy, E apex � max radiative power produced in the acceleration/emission regions • Cut-off energy, E cut � Maximum pair energy or γ - γ pair absorption N. Renault- 17 Tinacci

PSR J0030+0451 Preliminary P1 Leading P1 Core P1 Trailing BRI Bridge P3 P2 Leading P2 Core P2 Trailing N. Renault- 18 Tinacci

Preliminary Preliminary corr = 0.71 corr = -0.74 • The brighter the core, the harder the SED (lower Γ ), the higher the • Inconsistent with classical OG/SG apex energy models (harder 2 nd peak) – Irrespective of the peak order • Consistent with new FIDO model • Expected if dominant curv. (Kalopotharakos et al. 2014) • Potential diagnostic to radiation discriminate 1- vs 2-pole emission models 19

Preliminary P curv = 96,4 % P curv = 90,7 % � Correlation E apex with Ė P curv = 99,7 % � Correlation E apex with Ė P curv = 80,7 % � Possible correlation P2 C • E apex vs Ė P1 – Marginal P2 P2T C P1 P1T change across L P3 L phase BRI T1 N. Renault- 20 Tinacci

Preliminary P curv = 96,5 % P curv = 95,9 % � Correlation E apex with Ė P curv = 99,9 % � Correlation E apex with Ė P curv = 83,2 % � Possible correlation P2 C • E apex vs Ė P1 – Marginal P2 P2T C P1 P1T change across L P3 L phase BRI T1 N. Renault- 21 Tinacci