Search Publications
Extinction in the Large Magellanic Cloud Bar around NGC 1854, NGC 1856, and NGC 1858
Milone, Antonino P.; Panagia, Nino; De Marchi, Guido
We report on the extinction properties in the fields around the clusters NGC 1854, NGC 1856, and NGC 1858 in the bar of the Large Magellanic Cloud. The color-magnitude diagrams of the stars in all these regions show an elongated red giant clump that reveals a variable amount of extinction across these fields, ranging from A V ≃ 0.2 to…
Development of the Model of Galactic Interstellar Emission for Standard Point-source Analysis of Fermi Large Area Telescope Data
Troja, E.; Caraveo, P. A.; Mirabal, N. +131 more
Most of the celestial γ rays detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope originate from the interstellar medium when energetic cosmic rays interact with interstellar nucleons and photons. Conventional point-source and extended-source studies rely on the modeling of this diffuse emission for accurate char…
Ephemeris, orbital decay, and masses of ten eclipsing high-mass X-ray binaries
Bonnet-Bidaud, J. M.; Lutovinov, A.; Bozzo, E. +3 more
We update the ephemeris of the eclipsing high-mass X-ray binary (HMXB) systems LMC X-4, Cen X-3, 4U 1700-377, 4U 1538-522, SMC X-1, IGR J18027-2016, Vela X-1,IGR J17252-3616, XTE J1855-026, and OAO 1657-415 with the help of more than ten years of monitoring these sources with the All Sky Monitor onboard RXTE and with the Integral Soft Gamma-Ray Im…
Local H i Emissivity Measured with Fermi-LAT and Implications for Cosmic-Ray Spectra
Casandjian, Jean-Marc
Cosmic-ray (CR) electrons and nuclei interact with the Galactic interstellar gas and produce high-energy γ-rays. The γ-ray emission rate per hydrogen atom, called emissivity, provides a unique indirect probe of the CR flux. We present the measurement and the interpretation of the emissivity in the solar neighborhood for γ-ray energy from 50 MeV to…
Timing of gamma-ray pulsars: Search in seven-parametric space
Bisnovatyi-Kogan, G. S.; Repin, S. V.
Timing of the Geminga gamma-ray pulsar is done using the data of COS B and EGRET. It is shown, that errors in angular coordinates of sources similar to Geminga strongly influence the determination of , so that at angular precision less then 10^-3 arc sec determination of the value of by means of this criterion gives an error of more than 100%. Att…
Some problems of the detection of the high energy gamma-radiation in space
Fradkin, M. I.; Ginzburg, V. L.; Kurnosova, L. V. +8 more
The flux of the diffuse gamma-radiation in the Galaxy was measured with the instruments on board of the satellites COS-B and Compton Gamma Ray Observatory (CGRO). It was shown that the spectrum of the diffuse gamma-rays N(E) in the energy range from very low energy (some tens keV) up to some GeV may be represented by the expression N(E) = AE^kdE, …
A new γ-ray pulsar: PSR 0740-28
Lu, Tan; Ma, Yu-qian; Song, Li-ming
We made a period folding analysis on two sets of COS-B observations and obtained a clearly pulsed phase structure in the γ-ray photons from the direction of PSR 0740-28. The phase diagrams from the two different data sets have a similar structure and the period and period rate are close to radio expectations. The probability of the two phase struc…
Gamma-Ray Pulsar Studies with COMPTEL
Strong, A. W.; Grenier, I. A.; Diehl, R. +10 more
Since the launch of the Compton Gamma-Ray Observatory (CGRO) the number of detected gamma-ray pulsars increased from two to six. COMPTEL, on-board CGRO and sensitive to gamma-rays with energies between approximately 0.7 and 30 MeV, detected three of these unambiguously. The classical Crab and Vela pulsars have been observed on several occasions an…
Gamma Rays from the Geminga Pulsar: Variations with Time and Phase
Grenier, I. A.; Hermsen, W.; Bennett, K. +5 more
Pulsed gamma radiation from the Geminga pulsar was recorded by the COS B satellite from 50 MeV to 5 GeV between 1975 and 1982. It has been analyzed to derive the source spectral properties as a function of time and phase. The two main peaks are separated by 0.50 +/- 0.01 in phase. Significant pulsed emission has also been detected in both phase re…
The identification of the new gamma-ray pulsar PSR 1055-52 from COS-B data.
Song, L. -M.; Lu, T.