154 articles – 1958 Notices  [english version]
 HAL : in2p3-00608259, version 1
 Astrophysical Journal Letters 734 (2011) L35
 Search for Gravitational Wave Bursts from Six Magnetars
 VIRGO Collaboration(s)
 (2011)
 Soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are thought to be magnetars: neutron stars powered by extreme magnetic fields. These rare objects are characterized by repeated and sometimes spectacular gamma-ray bursts. The burst mechanism might involve crustal fractures and excitation of non-radial modes which would emit gravitational waves (GWs). We present the results of a search for GW bursts from six galactic magnetars that is sensitive to neutron star f-modes, thought to be the most efficient GW emitting oscillatory modes in compact stars. One of them, SGR 0501+4516, is likely ~1 kpc from Earth, an order of magnitude closer than magnetars targeted in previous GW searches. A second, AXP 1E 1547.0-5408, gave a burst with an estimated isotropic energy >1044 erg which is comparable to the giant flares. We find no evidence of GWs associated with a sample of 1279 electromagnetic triggers from six magnetars occurring between 2006 November and 2009 June, in GW data from the LIGO, Virgo, and GEO600 detectors. Our lowest model-dependent GW emission energy upper limits for band- and time-limited white noise bursts in the detector sensitive band, and for f-mode ringdowns (at 1090 Hz), are 3.0 × 1044 d 2 1 erg and 1.4 × 1047 d 2 1 erg, respectively, where $d_\mathrm{1} = \frac{d_{\mathrm{0501}}}{1\,\mathrm{kpc}}$ and d 0501 is the distance to SGR 0501+4516. These limits on GW emission from f-modes are an order of magnitude lower than any previous, and approach the range of electromagnetic energies seen in SGR giant flares for the first time.
 équipe(s) de recherche : APC - Cosmologie et GravitationOptique et PhotoniqueAPC - ADAMIS
 Thème(s) : Physique/Relativité Générale et Cosmologie Quantique
 in2p3-00608259, version 1 http://hal.in2p3.fr/in2p3-00608259 oai:hal.in2p3.fr:in2p3-00608259 Contributeur : Nicole Berger <> Soumis le : Mardi 12 Juillet 2011, 15:52:47 Dernière modification le : Vendredi 20 Avril 2012, 17:00:30