Sub-luminous γ-ray pulsars

Journal Article · Wed Aug 17 00:00:00 EDT 2011 · The Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/738/1/114· OSTI ID:1357201

Romani, R. W. ^[1]; Kerr, M. ^[1]; Craig, H. A. ^[1]; Johnston, S. ^[2]; Cognard, I. ^[3]; Smith, D. A. ^[4]

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1. Stanford Univ., Stanford, CA (United States)
2. Australia Telescope National Facility, Epping, NSW (Australia)
3. Lab. de Physique et Chimie de l'Environnement, Orleans Cedex (France); Observatoire de Paris, Nancay (France)
4. Univ. Bordeaux, Gradignan (France)

Here, most pulsars observed by the Fermi Large Area Telescope have γ-ray luminosities scaling with spin-down power $${\dot{E}}$$ as $$L_\gamma \approx ({\dot{E}}\, \times \, 10^{33}\,{\rm erg \,s^{-1}})^{1/2}$$. However, there exist one detection and several upper limits an order of magnitude or more fainter than this trend. We describe these "sub-luminous" γ-ray pulsars and discuss the case for this being an orientation effect. Of the 12 known young radio pulsars with $${\dot{E}}>10^{34}\, {\rm erg\,s^{-1}}$$ and d ≤ 2 kpc several are substantially sub-luminous. The limited available geometrical constraints favor aligned geometries for these pulsars, although no one case for alignment is compelling. In this scenario GeV emission detected from such sub-luminous pulsars can be due to a lower altitude, lower-power accelerator gap.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1357201
• Journal Information: The Astrophysical Journal, Vol. 738, Issue 1; ISSN 0004-637X
• Publisher: Institute of Physics (IOP)
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
gamma rays: stars
pulsars: general