J/A+A/640/A43ivo://CDS.VizieR/J/A+A/640/A43doi:10.26093/cds/vizier.36400043CDSYeung P.K.H.2020-10-12T12:36:26Z2020-08-10T07:41:13ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frpulsarsgamma-ray-astronomyThe Crab pulsar is a bright gamma-ray source, which has been detected at photon energies up to ~1TeV. Its phase-averaged and phase-resolved gamma-ray spectra below 10GeV exhibit exponential cutoffs, while those above 10GeV apparently follow simple power laws. We re-visit the gamma-ray properties of the Crab pulsar with ten-year Fermi Large Area Telescope (LAT) data in the range of 60MeV-500GeV. With the phase-resolved spectra, we investigate the origins and mechanisms responsible for the emissions. The phaseograms were reconstructed for different energy bands and further analysed using a wavelet decomposition. The phase-resolved energy spectra were combined with the observations of ground-based instruments, such as MAGIC and VERITAS, to achieve a larger energy converage. We fitted power-law models to the overlapping energy spectra from 10GeV to ~1TeV. In the fit, we included a relative cross-calibration of energy scales between air-shower-based gamma-ray telescopes with the orbital pair-production telescope from the Fermi mission. We confirm the energy-dependence of the gamma-ray pulse shape and, equivalently, the phase-dependence of the spectral shape for the Crab pulsar. A relatively sharp cutoff at a relatively high energy of ~8GeV is observed for the bridge-phase emission. The E>10 GeV spectrum observed for the second pulse peak is harder than those for other phases. In view of the diversity of phase-resolved spectral shapes of the Crab pulsar, we tentatively propose a multi-origin scenario where the polar-cap, outer-gap, and relativistic-wind regions are involved.2020A&A...640A..43Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/640/A43CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/124/123 : Atlas of the Crab pulsar pulse profiles (Massaro+ 1997)J/A+A/565/L12 : Crab pulsar 50-400GeV light curve (Aleksic+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/640/A43https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/640/A43http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/640/A43https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/640/A43https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/640/A43http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/640/A43GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapGamma-rayRadiodefaultJ/A+A/640/A43/fig1Phaseograms in different energy bands (Fig. 1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhbcPulse phase at the bin centertime.phasefloatF60MeVPulsed flux in 60-600MeV per 0.02 phase1e-09ph.cm**-2.s**-1phot.flux.density;em.gamma.harddoublee_F60MeV1-sigma uncertainty of F60MeV1e-09ph.cm**-2.s**-1stat.errordoubleF0.6GeVPulsed flux in 0.6-6GeV per 0.2 phase1e-09ph.cm**-2.s**-1phot.flux.density;em.gamma.harddoublee_F0.6GeV1-sigma uncertainty of F0.6GeV1e-09ph.cm**-2.s**-1stat.errordoubleF6GeVPulsed flux in 6-60GeV per 0.02 phase1e-09ph.cm**-2.s**-1phot.flux.density;em.gamma.harddoublee_F6GeV1-sigma uncertainty of F6GeV1e-09ph.cm**-2.s**-1stat.errordoubleF20GeVPulsed flux in 20-500GeV per 0.2 phase1e-09ph.cm**-2.s**-1phot.flux.density;em.gamma.harddoublee_F20GeV1-sigma uncertainty of F20GeV1e-09ph.cm**-2.s**-1stat.errordoubleJ/A+A/640/A43/fig3Phase-averaged pulsar & nebular spectra (Fig. 3)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEbcPhoton energy at the bin centerGeVem.energydoubleFPSR? E2dN/dE of the pulsar1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FPSR? 1-sigma uncertainty of FPSR1e-15W.m**-2stat.errordoublenullableFNebE2dN/dE of the nebula1e-15W.m**-2phot.flux.density;em.gamma.harddoublee_FNeb1-sigma uncertainty of FNeb1e-15W.m**-2stat.errordoubleJ/A+A/640/A43/fig4Phase-resolved pulsar spectra (Fig. 4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEbcPhoton energy at the bin centerGeVem.energydoubleFLW1? E2dN/dE/delta at LW1 (phase 0.88-0.96)1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FLW1? 1-sigma uncertainty of FLW11e-15W.m**-2stat.errordoublenullableFP1? E2dN/dE/delta at P1 (phase 0.96-0.02)1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FP1? 1-sigma uncertainty of FP11e-15W.m**-2stat.errordoublenullableFTW1? E2dN/dE/delta at TW1 (phase 0.02-0.12)1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FTW1? 1-sigma uncertainty of FTW11e-15W.m**-2stat.errordoublenullableFBD? E2dN/dE/delta at BD (phase 0.12-0.20)1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FBD? 1-sigma uncertainty of FBD1e-15W.m**-2stat.errordoublenullableFLW2? E2dN/dE/delta at LW2 (phase 0.20-0.36)1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FLW2? 1-sigma uncertainty of FLW21e-15W.m**-2stat.errordoublenullableFP2E2dN/dE/delta at P2 (phase 0.36-0.42)1e-15W.m**-2phot.flux.density;em.gamma.harddoublee_FP21-sigma uncertainty of FP21e-15W.m**-2stat.errordoubleFTW2? E2dN/dE/delta at TW2 (phase 0.42-0.58)1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FTW2? 1-sigma uncertainty of FTW21e-15W.m**-2stat.errordoublenullableJ/A+A/640/A43/fig9>10GeV pulsar spectra (dedicated to joint fits with IACT data; Fig. 9)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEbcMeasured photon energy at the bin centerGeVem.energydoubleFfpE2dN/dE in the full-phase1e-15W.m**-2phot.flux.density;em.gamma.harddoublee_Ffp1-sigma uncertainty of Ffp1e-15W.m**-2stat.errordoubleFP1M? E2dN/dE/delta at P1M (phase 0.983-0.026)1e-15W.m**-2phot.flux.density;em.gamma.harddoublenullablee_FP1M? 1-sigma uncertainty of FP1M1e-15W.m**-2stat.errordoublenullableFP2ME2dN/dE/delta at P2M (phase 0.377-0.422)1e-15W.m**-2phot.flux.density;em.gamma.harddoublee_FP2M1-sigma uncertainty of FP2M1e-15W.m**-2stat.errordouble