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Title: A LIKELY MILLISECOND PULSAR BINARY COUNTERPART FOR FERMI SOURCE 2FGL J2039.6–5620

We have identified an optical/X-ray binary with an orbital period of P{sub b} = 5.47 hr as the likely counterpart of the Fermi source 2FGL J2039.6−5620. GROND, SOAR, and DES observations provide an accurate orbital period and allow us to compare to the light curve of an archival XMM exposure. Like many short-period optical/X-ray binaries associated with Large Area Telescope sources, this may be an interacting (black widow/redback) millisecond pulsar binary. The X-ray light curve is consistent with the emission associated with an intrabinary shock. The optical light curve shows evidence of companion heating, but has a peculiar asymmetric double peak. The nature of this optical structure is not yet clear; additional optical studies and, in particular, detection of an orbital modulation in a γ-ray pulsar are needed to elucidate the nature of this peculiar source.
Authors:
 [1]
  1. Department of Physics, Stanford University, Stanford, CA 94305-4060 (United States)
Publication Date:
OSTI Identifier:
22518773
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 812; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; BINARY STARS; COMPARATIVE EVALUATIONS; COSMIC GAMMA SOURCES; COSMIC X-RAY SOURCES; DIAGRAMS; GAMMA RADIATION; HEATING; PULSARS; TELESCOPES; VISIBLE RADIATION; X RADIATION