First INTEGRAL observations of GRS 1915+105
/ Authors
D. Hannikainen, O. Vilhu, Jérôme Rodriguez, S. Brandt, N. Westergaard, N. Lund, I. Mocoeur, P. Durouchoux, T. Belloni, A. Castro-Tirado
and 13 more authors
P. Charles, A. Dean, R. Fender, M. Feroci, P. Hakala, R. Hunstead, C. Kaiser, A. King, I. Mirabel, G. Pooley, J. Poutanen, Kinwah Wu, A. Zdziarski
/ Abstract
We present data from the first of six monitoring Open Time observations of GRS 1915+105 undertaken with the orbiting INTEGRAL satellite. The source was clearly detected with all three X-ray and gamma-ray instruments on board. GRS 1915+105 was in a highly variable state, as demonstrated by the JEM X-2 and ISGRI lightcurves. These and simultaneous RXTE/PCA lightcurves point to a novel type of variability pattern in the source. In addition, we fit the combined JEM X-2 and ISGRI spectrum between 3-300 keV with a disk blackbody + powerlaw model leading to typical parameter values found earlier at similar luminosity levels. A new transient, IGR J19140+098, was discovered during the present observation.
Journal: Astronomy and Astrophysics