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Pulsars are born with subsecond spin periods and slow by electromagnetic braking for several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron stars in binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecond periods and begin radiating again. We searched(More)
Recent observations of supernova remnants (SNRs) hint that they accelerate cosmic rays to energies close to ~10(15) electron volts. However, the nature of the particles that produce the emission remains ambiguous. We report observations of SNR W44 with the Fermi Large Area Telescope at energies between 2 x 10(8) electron volts and 3 x10(11) electron volts.(More)
We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 ± 0.002 in phase. The first peak lags the maximum of the 2(More)
  • T Ekholm, P Teerikorpi, G Theureau, M Hanski, G Paturel, L Bottinelli +1 other
  • 1999
We derive the value of H 0 using the inverse diameter and magnitude B-band Tully-Fisher relations and the large all-sky sample KLUN (5171 spiral galaxies). Our kinematical model was that of Peebles centered at Virgo. Our calibrator sample consisted of 15 field galaxies with cepheid distance moduli measured mostly with HST. A straightforward application of(More)
  • P Teerikorpi, T Ekholm, M O Hanski, G Theureau
  • 1999
We study the influence of the assumption behind the use of the inverse Tully-Fisher relation: that there should be no observational cutoffs in the TF parameter log V M. It is noted how lower and upper cutoffs would be seen in a log H 0 vs. " normalized distance " diagram. Analytical expressions, under the simplifying assumption of a normal distribution and(More)
  • P Teerikorpi, M Hanski, G Theureau, Yu Baryshev, G Paturel, L Bottinelli +1 other
  • 1998
We have studied using the KLUN sample of 5171 spiral galaxies having Tully-Fisher distance moduli, the average radial space distribution of galaxies out to a distance of about 200 Mpc (for H 0 = 50 km s −1 Mpc −1). One motivation came from the debate on the fractal dimension D and maximum fractality scale λ max of the large-scale galaxy distribution (Davis(More)
  • G Paturel, P Lanoix, P Teerikorpi, G Theureau, L Bottinelli, L Gouguenheim +2 others
  • 1998
New distances, larger than previous ones, have been obtained for M 31 and M 81 based on the geometrical zero-point of the Cepheid Period-luminosity relation provided by the HIPPARCOS satellite. By combining them with independent determinations we define reasonable ranges for the distances of these important calibrating galaxies. On this basis, we determine(More)
Continuing our study of the type dependence of the TF relation, we present a new attempt to reduce the scatter of that relation by using the observed mean surface brightness Σ of galaxies. It is shown that the zero-point of the relation is a continuous function of Σ, well described by a third or fourth degree polynome. Taking this effect into account, the(More)
  • G Theureau, M Hanski, T Ekholm, L Bottinelli, L Gouguenheim, G Paturel +1 other
  • 1996
We have studied the value of the Hubble constant using the KLUN (Kinematics of the Local Universe) sample of 5171 spiral galaxies having isophotal diameters D 25 (and partially B-magnitudes), H i line widths, and radial velocities. The sample is diameter-limited, complete down to D 25 = 1.6 arcmin. As in the first similar study, where a much smaller(More)
The paucity of observed supermassive black hole binaries (SMBHBs) may imply that the gravitational wave background (GWB) from this population is anisotropic, rendering existing analyses suboptimal. We present the first constraints on the angular distribution of a nanohertz stochastic GWB from circular, inspiral-driven SMBHBs using the 2015 European Pulsar(More)