A stacked analysis of 115 pulsars observed by the Fermi LAT

Abstract

Due to the low gamma-ray fluxes from pulsars above 50 GeV and the small collecting area of space-based telescopes, the gamma-ray emission discovered by the Fermi-LAT in $\sim$150 pulsars is largely unexplored at these energies. In this regime, the uncertainties on the spectral data points and/or the constraints from upper-limits are not sufficient to provide robust tests of competing emission models in individual pulsars. The discovery of power-law-type emission from the Crab pulsar at energies exceeding 100 GeV provides a compelling justification for exploration of other pulsars at these energies. We applied the method of Aperture Photometry to measure pulsar emission spectra from Fermi-LAT data and present a stacked analysis of 115 pulsars selected from the Second Fermi-LAT Catalog of Gamma-ray Pulsars. This analysis, which uses an average of $\sim$4.2 years of data per pulsar, aggregates low-level emission which cannot be resolved in individual objects but can be detected in an ensemble. We find no significant stacked excess at energies above 50 GeV. An upper limit of $\sim$30% of the Crab pulsar level is found for the average flux from 115 pulsars in the 100-177 GeV energy range at the 95% confidence level. Stacked searches exclusive to the young pulsar sample, the millisecond pulsar sample, and several other promising sub-samples also return no significant excesses above 50 GeV.

arXiv comment10 pages, 8 Figures, 3 Tables. Accepted for publication in ApJ

References in corpus (24)

• TEMPO2, a new pulsar timing package. I: Overview
• The Second Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• Studies in Astronomical Time Series Analysis. VI. Bayesian Block Representations
• Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope
• Detection of a Gamma-Ray Source in the Galactic Center Consistent with Extended Emission from Dark Matter Annihilation and Concentrated Astrophysical Emission
• An Algorithm for Optimal Partitioning of Data on an Interval
• The First Fermi-LAT Catalog of Sources Above 10 GeV
• Detection of Pulsed Gamma Rays Above 100 GeV from the Crab Pulsar
• High-Altitude Emission from Pulsar Slot Gaps: The Crab Pulsar
• The Vela Pulsar: Results from the First Year of Fermi LAT Observations
• Phase-resolved energy spectra of the Crab Pulsar in the range of 50-400 GeV measured with the MAGIC Telescopes
• Observations of the Crab pulsar between 25 GeV and 100 GeV with the MAGIC I telescope
• Determination of the Point-Spread Function for the Fermi Large Area Telescope from On-orbit Data and Limits on Pair Halos of Active Galactic Nuclei
• The very-high energy emission from pulsars: a case for inverse Compton scattering
• High-energy emission from the pulsar striped wind: a synchrotron model for gamma-ray pulsars
• Observations of 54 Active Galactic Nuclei with the HEGRA System of Cherenkov Telescopes
• Pulse Profiles, Spectra and Polarization Characteristics of Non-Thermal Emissions from the Crab-Like Pulsars
• Radio-to-TeV Phase-resolved Emission from the Crab Pulsar: The Annular Gap Model
• Fermi-LAT Detection of Pulsed Gamma-rays Above 50 GeV from the Vela Pulsar
• Gamma-Ray Emissions from Pulsars: Spectra of the TEV Fluxes from Outer-Gap Accelerators
• Inverse Compton model of pulsar high energy emission
• A Search for Pulsations from Geminga Above 100 GeV with VERITAS
• Magnetic Pair Creation Transparency in Gamma-Ray Pulsars
• The gamma-ray spectrum of Geminga and the inverse Compton model of pulsar high energy emission

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• The Fermi Galactic Center GeV Excess and Implications for Dark Matter
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• Synchrotron Self-Compton Emission from the Crab and Other Pulsars
• First Ground-based Measurement of Sub-20 GeV to 100 GeV $\gamma$-rays from the Vela Pulsar with H.E.S.S. II
• Bayesian Model Comparison and Analysis of the Galactic Disk Population of Gamma-Ray Millisecond Pulsars
• Order parameters for the high-energy spectra of pulsars
• Analyzing γ-rays of the Galactic Center with Deep Learning
• Very-High-Energy Emission From Pulsars
• Modeling of the gamma-ray pulsed spectra of Geminga, Crab, and Vela with synchro-curvature radiation
• Robust inference of the Galactic centre gamma-ray excess spatial properties
• Gamma-ray emission from PSR J0007+7303 using 7 years of Fermi Large Area Telescope observations
• Mind the gap: The discrepancy between simulation and reality drives interpretations of the Galactic Center Excess
• A Search for Pulsed Very High-Energy Gamma Rays from Thirteen Young Pulsars in Archival VERITAS Data
• A Stacking Survey of Gamma-ray Pulsars
• Pulsar Emission above the Spectral Break - A Stacked Approach
• Implications of the Fermi-LAT Pass 8 Galactic Center Excess on Supersymmetric Dark Matter
• Extended Higgs-portal dark matter and the Fermi-LAT Galactic Center Excess
• The Effect of Pulsar Geometry on the Observed Gamma-ray Spectrum of Millisecond Pulsars