Abstract
Discovered after the end of the Compton Gamma-Ray Observatory mission, the radio pulsar PSR J2021 + 3651 was long considered a likely counterpart of the high-energy γ-ray source 2CG 075 + 00=3EG J2021+3716=GeV J2020 + 3658, but it could not be confirmed due to the lack of a contemporaneous radio pulsar ephemeris to fold the sparse, archival γ-ray photons. Here, we report the discovery of γ-ray pulsations from PSR J2021 + 3651 in the 100-1500 MeV range using data from the AGILE satellite gathered over 8 months, folded on a densely sampled, contemporaneous radio ephemeris obtained for this purpose at the Green Bank Telescope. The γ-ray pulse consists of two sharp peaks separated by 0.47 ± 0.01 cycles. The single radio pulse leads the first γ-ray peak by 0.165 ± 0.010 cycles. These properties are similar to those of other ±-ray pulsars, and the phase relationship of the peaks can be interpreted in the context of the outer-gap accelerator model for ±-ray emission. Pulse-phase-resolved images show that there is only one dominant source, AGL J2020.5+3653=PSR J2021+3651, in the region previously containing confused sources 3EG J2021+3716 and 3EG J2016+3657.
Original language | English (US) |
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Pages (from-to) | L33-L36 |
Journal | Astrophysical Journal |
Volume | 687 |
Issue number | 1 PART 2 |
DOIs | |
State | Published - 2008 |
Keywords
- Observations
- Pulsars
- Subject headings
- gamma rays
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science