Yosuke Takahashi, Jun Kataoka, Takeshi Nakamori, Koto Maeda, Ryu Makiya, Tomonori Totani, Chi Chiu Cheung, Łukasz Stawarz, Lucas Guillemot, Paulo César Carvalho Freire, Ismaël Cognard
We report on our second-year campaign of X-ray follow-up observations of
unidentified Fermi-LAT \gamma-ray sources at high Galactic latitudes (|b|>10
degree) using the X-ray Imaging Spectrometer onboard the Suzaku X-ray
Observatory. In this second year of the project, seven new targets were
selected from the First Fermi-LAT Catalog, and studied with 20-40 ks effective
Suzaku exposures. We detected an X-ray point source coincident with the
position of the recently discovered millisecond pulsar PSR J2302+4442 within
the 95% confidence error circle of 1FGL J2302.8+4443. The X-ray spectrum of the
detected counterpart was well fit by a blackbody model with temperature of kT
~0.3 keV, consistent with an origin of the observed X-ray photons from the
surface of a rotating magnetized neutron star. For four other targets which
were also recently identified with a normal pulsar (1FGL J0106.7+4853) and
millisecond pulsars (1FGL J1312.6+0048, J1902.0-5110, and J2043.2+1709), only
upper limits in the 0.5-10 keV band were obtained at the flux levels of
~10^{-14} erg cm^{-2} s^{-1}. A weak X-ray source was found in the field of
1FGL J1739.4+8717, but its association with the variable \gamma-ray emitter
could not be confirmed with the available Suzaku data alone. For the remaining
Fermi-LAT object 1FGL J1743.8-7620 no X-ray source was detected within the LAT
95% error ellipse. We briefly discuss the general properties of the observed
high Galactic-latitude Fermi-LAT objects by comparing their multiwavelength
properties with those of known blazars and millisecond pulsars.
View original:
http://arxiv.org/abs/1112.4933
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