Constraining pulsar gap models with the light-curve and flux properties of the gamma-ray pulsar population

We compare population synthesis results for inner and outer magnetosphere emission models with the various characteristics measured in the first LAT pulsar catalogue for both the radio-loud and radio-weak or radio-quiet gamma-ray pulsars. We show that all models fail to reproduce the observations: for each model there is a lack of luminous and energetic objects that suggest a non dipolar magnetic field structure or spin-down evolution. The large dispersion that we find in the simulated gamma-ray luminosity versus spin-down power relation does not allow to use the present trend seen in the Fermi data to distinguish among models. For each model and each Fermi detected pulsar, we have generated light curves as a function of obliquity and inclination angles. The theoretical curves were fitted to the observed one, using a maximum-likelihood approach, to derive the best-fit orientations and to compare how well each model can reproduce the data. Including the radio light-curve gives an additional key constraint to restrict the orientation spaceComment: 4 pages, 3 figures, to appear in the proceedings of the Pulsar 2010 Conference, Italy, 10 - 15 October 201

ERRATUM: "FERMI DETECTION OF γ-RAY EMISSION FROM THE M2 SOFT X-RAY FLARE ON 2010 JUNE 12" (2012, ApJ, 745, 144)

Due to an error at the publisher, the times given for the major tick marks in the X-axis in Figure 1 of the published article are incorrect. The correctly labeled times should be "00:52:00," "00:54:00," ... , and "01:04:00." The correct version of Figure 1 and its caption is shown below. IOP Publishing sincerely regrets this error

Physique des pulsars de rayonnement gamma (modélisation des régions d'émission)

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Discovery of Pulsations from the pulsars J0205+6449 in SNR 3C 58 with the Fermi Gammay-ray Space Telescope

7 pages, 1 figureInternational audienceWe report the discovery of γ-ray pulsations (≥0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the γ-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold γ-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 ± 0.01 ± 0.01 cycles which are aligned with the X-ray peaks. The first γ-ray peak trails the radio pulse by 0.08 ± 0.01 ± 0.01, while its amplitude decreases with increasing energy as for the other γ-ray pulsars. Spectral analysis of the pulsed γ-ray emission suggests a simple power law of index –2.1 ± 0.1 ± 0.2 with an exponential cutoff at 3.0+1.1 –0.7 ± 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral γ-ray photon flux above 0.1 GeV is (13.7 ± 1.4 ± 3.0) × 10–8 cm–2 s–1, which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 × 1034 erg s–1 and an efficiency η of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 × 10–8 cm–2 s–1 for off-pulse emission from the object

THE SECOND CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE

The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years of scientific operation is presented. The second LAT AGN catalog (2LAC) includes 1017 γ-ray sources located at high Galactic latitudes (|b| > 10°) that are detected with a test statistic (TS) greater than 25 and associated statistically with AGNs. However, some of these are affected by analysis issues and some are associated with multiple AGNs. Consequently, we define a Clean Sample which includes 886 AGNs, comprising 395 BL Lacertae objects (BL Lac objects), 310 flat-spectrum radio quasars (FSRQs), 157 candidate blazars of unknown type (i.e., with broadband blazar characteristics but with no optical spectral measurement yet), 8 misaligned AGNs, 4 narrow-line Seyfert 1 (NLS1s), 10 AGNs of other types, and 2 starburst galaxies. Where possible, the blazars have been further classified based on their spectral energy distributions (SEDs) as archival radio, optical, and X-ray data permit. While almost all FSRQs have a synchrotron-peak frequency 1015 Hz. The 2LAC represents a significant improvement relative to the first LAT AGN catalog (1LAC), with 52% more associated sources. The full characterization of the newly detected sources will require more broadband data. Various properties, such as γ-ray fluxes and photon power-law spectral indices, redshifts, γ-ray luminosities, variability, and archival radio luminosities and their correlations are presented and discussed for the different blazar classes. The general trends observed in 1LAC are confirmed

The Vela Pulsar: Results from the First Year of Fermi LAT Observations

35 pages, 12 figures, accepted for publication in Astrophysical JournalWe report on analysis of timing and spectroscopy of the Vela pulsar using eleven months of observations with the Large Area Telescope on the Fermi Gamma-Ray Space Telescope. The intrinsic brightness of Vela at GeV energies combined with the angular resolution and sensitivity of the LAT allow us to make the most detailed study to date of the energy-dependent light curves and phase-resolved spectra, using a LAT-derived timing model. The light curve consists of two peaks (P1 and P2) connected by bridge emission containing a third peak (P3). We have confirmed the strong decrease of the P1/P2 ratio with increasing energy seen with EGRET and previous Fermi LAT data, and observe that P1 disappears above 20 GeV. The increase with energy of the mean phase of the P3 component can be followed with much greater detail, showing that P3 and P2 are present up to the highest energies of pulsation. We find significant pulsed emission at phases outside the main profile, indicating that magnetospheric emission exists over 80% of the pulsar period. With increased high-energy counts the phase-averaged spectrum is seen to depart from a power- law with simple exponential cutoff, and is better fit with a more gradual cutoff. The spectra in fixed-count phase bins are well fit with power-laws with exponential cutoffs, revealing a strong and complex phase dependence of the cutoff energy, especially in the peaks. By combining these results with predictions of the outer magnetosphere models that map emission characteristics to phase, it will be possible to probe the particle acceleration and the structure of the pulsar magnetosphere with unprecedented detail

Discovery of Pulsations from the pulsars J0205+6449 in SNR 3C 58 with the Fermi Gammay-ray Space Telescope

7 pages, 1 figureInternational audienceWe report the discovery of γ-ray pulsations (≥0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the γ-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold γ-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 ± 0.01 ± 0.01 cycles which are aligned with the X-ray peaks. The first γ-ray peak trails the radio pulse by 0.08 ± 0.01 ± 0.01, while its amplitude decreases with increasing energy as for the other γ-ray pulsars. Spectral analysis of the pulsed γ-ray emission suggests a simple power law of index –2.1 ± 0.1 ± 0.2 with an exponential cutoff at 3.0+1.1 –0.7 ± 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral γ-ray photon flux above 0.1 GeV is (13.7 ± 1.4 ± 3.0) × 10–8 cm–2 s–1, which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 × 1034 erg s–1 and an efficiency η of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 × 10–8 cm–2 s–1 for off-pulse emission from the object

Discovery of Pulsations from the pulsars J0205+6449 in SNR 3C 58 with the Fermi Gammay-ray Space Telescope

7 pages, 1 figureInternational audienceWe report the discovery of γ-ray pulsations (≥0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the γ-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold γ-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 ± 0.01 ± 0.01 cycles which are aligned with the X-ray peaks. The first γ-ray peak trails the radio pulse by 0.08 ± 0.01 ± 0.01, while its amplitude decreases with increasing energy as for the other γ-ray pulsars. Spectral analysis of the pulsed γ-ray emission suggests a simple power law of index –2.1 ± 0.1 ± 0.2 with an exponential cutoff at 3.0+1.1 –0.7 ± 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral γ-ray photon flux above 0.1 GeV is (13.7 ± 1.4 ± 3.0) × 10–8 cm–2 s–1, which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 × 1034 erg s–1 and an efficiency η of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 × 10–8 cm–2 s–1 for off-pulse emission from the object