Context. Magnetars are an extreme, highly magnetized class of isolated neutron stars whose large X-ray luminosity is believed to be driven by their high magnetic field. Aims. We study for the first time the possible very high energy γ-ray emission above 100GeV from magnetars, observing the sources 4U0142+61 and 1E2259+586. Methods. We observed the two sources with atmospheric Cherenkov telescopes in the very high energy range (E> 100GeV). 4U0142+61 was observed with the MAGICA I telescope in 2008 for about 25h and 1E2259+586 was observed with the MAGIC stereoscopic system in 2010 for about 14h. The data were analyzed with the standard MAGIC analysis software. Results. Neither magnetar was detected. Upper limits to the differential and integral flux above 200GeV were computed using the Rolke algorithm. We obtain integral upper limits to the flux of 1.52 × 10-12cm-2s-1 and 2.7 × 10-12 cm-2s-1 with a confidence level of 95% for 4U0142+61 and 1E2259+586, respectively. The resulting differential upper limits are presented together with X-ray data and upper limits in the GeV energy range. © 2012 ESO.
- Gamma rays: stars
- Radiation mechanisms: non-thermal
- Stars: individual: 1E 2259+586
- Stars: individual: 4U 0142+61
- Stars: magnetars