Discovery of gamma- and X-ray pulsations from the young and energetic PSR J1357−6429 with Fermi and XMM-Newton
M. Lemoine-Goumard1*, V. E. Zavlin2, M.-H. Grondin3, R. Shannon4, D. A. Smith1, M. Burgay5, F. Camilo6, J. Cohen-Tanugi7, P. C. C. Freire8, J. E. Grove9, L. Guillemot8, S. Johnston4, M. Keith4, M. Kramer8,10, R. N. Manchester4, P. F. Michelson11, D. Parent12, A. Possenti5, P. S. Ray9, M. Renaud7, S. E. Thorsett13, P. Weltevrede10 and M. T. Wolff9
Université Bordeaux 1, CNRS/IN2P3, Centre d’Études Nucléaires de Bordeaux
e-mail: email@example.com; firstname.lastname@example.org
2 Space Science laboratory, Universities Space Research Association, NASA MSFC VP62, Huntsville, AL 35805, USA
3 Institut für Astronomie und Astrophysik, Universität Tübingen, 72076 Tübingen, Germany
4 CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping NSW 1710, Australia
5 INAF – Cagliari Astronomical Observatory, 09012 Capoterra ( CA), Italy
6 Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
7 Laboratoire Univers et Particules de Montpellier, Université Montpellier 2, CNRS/IN2P3, Montpellier, France
8 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
9 High Energy Space Environment Branch, Naval Research Laboratory, Washington, DC 20375, USA
10 Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, M13 9PL, UK
11 W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305, USA
12 Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030, resident at Naval Research Laboratory, Washington, DC 20375, USA
13 Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
Received: 6 June 2011
Accepted: 20 July 2011
Context. Since the launch of the Fermi satellite, the number of known gamma-ray pulsars has increased tenfold. Most gamma-ray detected pulsars are young and energetic, and many are associated with TeV sources. PSR J1357−6429 is a high spin-down power pulsar (Ė = 3.1 × 1036 erg s-1), discovered during the Parkes multibeam survey of the Galactic plane, with significant timing noise typical of very young pulsars. In the very-high-energy domain (E > 100 GeV), H.E.S.S. has reported the detection of the extended source HESS J1356−645 (intrinsic Gaussian width of 12′) whose centroid lies 7′ from PSR J1357−6429.
Aims. We search for gamma- and X-ray pulsations from this pulsar, characterize the neutron star emission and explore the environment of PSR J1357−6429.
Methods. Using a rotational ephemeris obtained with 74 observations made with the Parkes telescope at 1.4 GHz, we phase-fold more than two years of gamma-ray data acquired by the Large Area Telescope on-board Fermi as well as those collected with XMM-Newton, and perform gamma-ray spectral modeling.
Results. Significant gamma- and X-ray pulsations are detected from PSR J1357−6429. The light curve in both bands shows one broad peak. Gamma-ray spectral analysis of the pulsed emission suggests that it is well described by a simple power-law of index 1.5 ± 0.3stat ± 0.3syst with an exponential cut-off at 0.8 ± 0.3stat ± 0.3syst GeV and an integral photon flux above 100 MeV of (6.5 ± 1.6stat ± 2.3syst) × 10-8 cm-2 s-1. The X-ray spectra obtained from the new data provide results consistent with previous work. Upper limits on the gamma-ray emission from its potential pulsar wind nebula (PWN) are also reported.
Conclusions. Assuming a distance of 2.4 kpc, the Fermi LAT energy flux yields a gamma-ray luminosity for PSR J1357−6429 of Lγ = (2.13 ± 0.25stat ± 0.83syst) × 1034 erg s-1, consistent with an relationship. The Fermi non-detection of the pulsar wind nebula associated with HESS J1356−645 provides new constraints on the electron population responsible for the extended TeV emission.
Key words: pulsars: individual: PSR J1357 / 6429 / gamma rays: general / pulsars: general
© ESO, 2011