Les migrations résidentielles des Britanniques et des Néerlandais

Cognard, Françoise

doi:10.4000/eps.4672

Cited by 12 publications

(10 citation statements)

References 4 publications

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“…In almost three years since the launch of FGST, the sensitivity of the instrument has facilitated the discovery of new classes of objects, including gamma-ray pulsars. Over 80 gamma-ray pulsars have been discovered in the Fermi−LAT all-sky data (see Abdo et al (2010e), and also Abdo et al (2008Abdo et al ( , 2011Abdo et al ( , 2009bAbdo et al ( , 2010bAbdo et al ( , 2009c; Cognard et al (2011); Ray et al (2011); Ransom et al (2011);Saz Parkinson et al (2010); Abdo et al (2010a,b); Keith et al (2011)).…”

Section: Introductionmentioning

confidence: 99%

Extracting the unresolved pulsar contribution to the gamma-ray background

Geringer-Sameth¹,

Koushiappas²

2012

Monthly Notices of the Royal Astronomical Society

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We present a statistical framework which can be used to determine the contribution of an unresolved population of pulsars to the gamma‐ray background. This formalism is based on the joint analysis of photon time series over extended regions of the sky. We demonstrate the robustness of this technique in controlled simulations of pulsar populations, and show that the Fermi Gamma‐ray Space Telescope can be used to detect a pulsar contribution as small as 0.1 per cent of the gamma‐ray background. This technique is sensitive to pulsar populations with photon fluxes greater than ∼10−10 cm−2 s−1. The framework is extensible to arbitrarily complex searches for periodicity and can therefore be tailored to specific applications such as all‐sky surveys and studies of the Galactic Centre and globular clusters.

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Section: Introductionmentioning

confidence: 99%

Extracting the unresolved pulsar contribution to the gamma-ray background

Geringer-Sameth¹,

Koushiappas²

2012

Monthly Notices of the Royal Astronomical Society

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“…Following the first Fermi Catalog which included about 1 500 γ-ray sources [3], the second Fermi Catalog is in now production, containing nearly 1 900 γ-ray sources [4,5] including almost 100 γ-ray pulsars [6,7]. About a third of these are millisecond pulsars (MSPs), some having been found by observing non-variable, unassociated Fermi sources at high latitudes with radio telescopes and searching for pulsed radio signals [8,9,10]. Some of these MSPs exhibit the unusual phenomenon that the peaks of their γ-ray and radio LCs occur at the same observer phase ('longitude' φ), i.e., they are phase-aligned.…”

Section: γ-Ray Pulsars Galorementioning

confidence: 99%

What can we learn from phase alignment of gamma-ray and radio pulsar light curves?

Venter,

Johnson,

Harding

2011

Preprint

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The Fermi Large Area Telescope (LAT) has revolutionized high-energy (HE) astronomy, and is making enormous contributions particularly to γ-ray pulsar science. As a result of the many new pulsar discoveries, the γ-ray pulsar population is now approaching 100. Some very famous millisecond pulsars (MSPs) have also been detected: J1939+2134 (B1937+21), the first MSP ever discovered, as well as J1959+2048 (B1957+20), the first black widow pulsar system. These, along with other MSPs such as PSR J0034−0534 and J2214+3000, are rare among the pulsar population in that they exhibit nearly phasealigned radio and γ-ray light curves (LCs). Traditionally, pulsar LCs have been modelled using standard HE models in conjunction with low-altitude conal beam radio models. However, a different approach is needed to account for phase-aligned LCs. We explored two scenarios: one where both the radio and γ-ray emission originate in the outer magnetosphere, and one where the emission comes from near the polar caps (PCs) on the stellar surface. We find best-fit LCs using a Markov chain Monte Carlo (MCMC) technique for the first class of models. The first scenario seems to be somewhat preferred, as is also hinted at by the radio polarization data. This implies that the phase-aligned LCs are possibly of caustic origin produced in the outer magnetosphere, in contrast to the usual lower-altitude conal beam radio models. Lastly, we constrain the emission altitudes with typical uncertainties of ∼ 10% of the light cylinder radius. The modelled pulsars are members of a third γ-ray MSP subclass, in addition to two others with non-aligned radio and γ-ray LCs.

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“…The physical connection was however viewed as unlikely, since the X-ray source did not coincide with the location of the MSP PSR J2017+0603 discovered by the Nanc ¸ay radio telescope which constituted a more highly probable association with the Fermi-LAT object (Cognard et al 2011). The MSP identification was later indeed confirmed by the detection of the pulsed emission in the Fermi-LAT data, with the same period as the radio pulsations.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper, we report the results of our second-year campaign, conducted over the span of Suzaku Since then however, four of the selected targets have been associated with MSPs: 1FGL J1902.0−5110 with PSR J1902−5105 (Camilo et al 2011), 1FGL J2043.2+1709 with PSR J2043+1711 (Guillemot et al 2011), 1FGL J2302.8+4443 with PSR J2302+4442 (Cognard et al 2011), and 1FGL J1312.6+0048 with -4 -PSR J1312+00 (Abdo et al 2011). And moreover, 1FGL J0106.7+4853 have very recently been associated with a normal pulsar PSR J0106+4855 (Pletsch et al 2011).…”

Section: Introductionmentioning

confidence: 99%

SUZAKUX-RAY FOLLOW-UP OBSERVATIONS OF SEVEN UNASSOCIATEDFERMI-LAT GAMMA-RAY SOURCES AT HIGH GALACTIC LATITUDES

Takahashi¹,

Kataoka²,

Nakamori³

et al. 2012

ApJ

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7We report on our second-year campaign of X-ray follow-up observations of unidentified Fermi-LAT γ-ray sources at high Galactic latitudes (|b| > 10 • ) 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 γ-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.

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Les migrations résidentielles des Britanniques et des Néerlandais

Cited by 12 publications

References 4 publications

Extracting the unresolved pulsar contribution to the gamma-ray background

Extracting the unresolved pulsar contribution to the gamma-ray background

What can we learn from phase alignment of gamma-ray and radio pulsar light curves?

SUZAKUX-RAY FOLLOW-UP OBSERVATIONS OF SEVEN UNASSOCIATEDFERMI-LAT GAMMA-RAY SOURCES AT HIGH GALACTIC LATITUDES

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