Title: PSR J0007+7303 In The CTA1 Supernova Remnant: New Gamma-Ray Results From Two Years Of Fermi Large Area Telescope Observations

Abstract

One of the main results of the Fermi Gamma-Ray Space Telescope is the discovery of γ-ray selected pulsars. The high magnetic field pulsar, PSR J0007+7303 in CTA1, was the first ever to be discovered through its γ-ray pulsations. Based on analysis of 2 years of LAT survey data, we report on the discovery of γ-ray emission in the off-pulse phase interval at the ~ 6σ level. The flux from this emission in the energy range E ≥ 100 MeV is F100 = (1.73±0.40)×10^-8 photons cm^-2 s^-1 and is best fitted by a power law with a photon index of Γ = 2.54±0.14. The pulsed -ray flux in the same energy range is F100 = (3.95±0.07)×10^-7 photons cm^-2 s^-1 and is best fitted by an exponentially-cutoff power-law spectrum with a photon index of Γ = 1.41 ± 0.23 and a cutoff energy Ec = 4.04 ± 0.20 GeV. We find no flux variability neither at the 2009 May glitch nor in the long term behavior. We model the γ-ray light curve with two high-altitude emission models, the outer gap and slot gap, and find that the model that best fits the data depends strongly on the assumed origin of the off-pulsemore » emission. Both models favor a large angle between the magnetic axis and observer line of sight, consistent with the nondetection of radio emission being a geometrical effect. Finally we discuss how the LAT results bear on the understanding of the cooling of this neutron star.« less

Authors:

Abdo, A. A. ^[1]; Wood, K. S. ^[2]; DeCesar, M. E. ^[3]; Gargano, F. ^[4]; Giordano, F. ^[5]; Ray, P. S. ^[2]; Parent, D. ^[1]; Harding, A. K. ^[6]; Coleman Miller, M. ^[7]; Wood, D. L. ^[8]; Wolff, M. T. ^[2]

---

+ Show Author Affiliations

1. George Mason Univ., Fairfax, VA (United States); Naval Research Lab. (NRL), Washington, DC (United States)
2. Naval Research Lab. (NRL), Washington, DC (United States)
3. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, College Park, MD (United States)
4. Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy)
5. Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); Univ. e del Politecnico di Bari (Italy)
6. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
7. Univ. of Maryland, College Park, MD (United States)
8. Praxis Inc., Alexandria, VA (United States); Naval Research Lab. (NRL), Washington, DC (United States)

Publication Date:

Thu Dec 22 00:00:00 EST 2011

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1356766

Grant/Contract Number:  

AC02-76SF00515

Resource Type:

Accepted Manuscript

Journal Name:

The Astrophysical Journal

Additional Journal Information:

Journal Volume: 744; Journal Issue: 2; Journal ID: ISSN 0004-637X

Publisher:

Institute of Physics (IOP)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS