Institution: | Institute for Nuclear Research, Russian Academy of Sciences, Prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia;Astro Space Centre, Lebedev Physical Institute, Profsoyuznaya 84/32, Moscow 117997, Russia;Astronomy Division, Department of Physical Sciences, PO Box 3000, FIN-90014 University of Oulu, Finland |