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Title: Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data

Abstract

The flux of positrons and electrons (e + + e -) has been measured by the Fermi Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. Here, we discuss a number of interpretations of Pass 8 Fermi-LAT e + + e - spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays (CRs) with the interstellar medium. We also found that the Fermi-LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positrons from cataloged PWNe, and a secondary component. If we include in our analysis constraints from the AMS-02 positron spectrum, we obtain a slightly worse fit to the e + + e - Fermi-LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the individual sources found in Green's catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the e + + e - Fermi-LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is themore » main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured e + + e -spectrum and, among the CR propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.« less

Authors:
 [1];  [2];  [3]; ORCiD logo [2]; ORCiD logo [2]; ORCiD logo [4];  [2];  [4];  [5];  [5]; ORCiD logo [4];  [2]; ORCiD logo [6]; ORCiD logo [6];  [6]
  1. Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology, Dept. of Physics
  2. Univ. of Torino (Italy). Dept. of Physics; National Inst. of Nuclear Physics, Torino (Italy)
  3. Technical Univ. of Munich, Garching (Germany). Dept. of Physics
  4. Univ. of Pisa (Italy). National Inst. of Nuclear Physics
  5. National Inst. of Nuclear Physics, Torino (Italy)
  6. National Inst. of Nuclear Physics, Pisa (Italy)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1389288
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 845; Journal Issue: 2; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS

Citation Formats

Di Mauro, M., Manconi, S., Vittino, A., Donato, F., Fornengo, N., Baldini, L., Bonino, R., Di Lalla, N., Latronico, L., Maldera, S., Manfreda, A., Negro, M., Pesce-Rollins, M., Sgrò, C., and Spada, F.. Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data. United States: N. p., 2017. Web. doi:10.3847/1538-4357/aa8225.
Di Mauro, M., Manconi, S., Vittino, A., Donato, F., Fornengo, N., Baldini, L., Bonino, R., Di Lalla, N., Latronico, L., Maldera, S., Manfreda, A., Negro, M., Pesce-Rollins, M., Sgrò, C., & Spada, F.. Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data. United States. doi:10.3847/1538-4357/aa8225.
Di Mauro, M., Manconi, S., Vittino, A., Donato, F., Fornengo, N., Baldini, L., Bonino, R., Di Lalla, N., Latronico, L., Maldera, S., Manfreda, A., Negro, M., Pesce-Rollins, M., Sgrò, C., and Spada, F.. Thu . "Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data". United States. doi:10.3847/1538-4357/aa8225. https://www.osti.gov/servlets/purl/1389288.
@article{osti_1389288,
title = {Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data},
author = {Di Mauro, M. and Manconi, S. and Vittino, A. and Donato, F. and Fornengo, N. and Baldini, L. and Bonino, R. and Di Lalla, N. and Latronico, L. and Maldera, S. and Manfreda, A. and Negro, M. and Pesce-Rollins, M. and Sgrò, C. and Spada, F.},
abstractNote = {The flux of positrons and electrons (e+ + e-) has been measured by the Fermi Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. Here, we discuss a number of interpretations of Pass 8 Fermi-LAT e+ + e- spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays (CRs) with the interstellar medium. We also found that the Fermi-LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positrons from cataloged PWNe, and a secondary component. If we include in our analysis constraints from the AMS-02 positron spectrum, we obtain a slightly worse fit to the e+ + e- Fermi-LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the individual sources found in Green's catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the e+ + e- Fermi-LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is the main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured e+ + e-spectrum and, among the CR propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.},
doi = {10.3847/1538-4357/aa8225},
journal = {The Astrophysical Journal (Online)},
number = 2,
volume = 845,
place = {United States},
year = {Thu Aug 17 00:00:00 EDT 2017},
month = {Thu Aug 17 00:00:00 EDT 2017}
}

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