Mid-Infrared observations of GRS 1915+105 during plateau and flaring states

Abstract

We present mid-infrared (4-18 micron) observations of the microquasar GRS 1915+105 obtained with ISOCAM, the camera on board the Infrared Space Observatory (ISO), in 1996 April and 1997 October. The first observation probably occurred during a flaring event with oscillating synchrotron emission. The 1997 observation occurred a few days before a major relativistic ejection, during a plateau state of inverted-spectrum radio emission and hard quasi-stable X-ray emission. The K-M giant donor star in GRS 1915+105 cannot account for the mid-IR emission and we discuss the possible additional components depending on two absorption laws. Thermal emission from dust seems unlikely. The flat mid-IR spectrum obtained during the plateau state is likely to be synchrotron emission. It would be the first evidence of the infrared extension of the radio synchrotron emission from the compact jets, although optically thin free-free emission from an X-ray driven-wind from the accretion disc cannot be excluded.

12 pages, 5 figures, accepted by A&A

References in corpus (2)

• The Chandra HETGS and RXTE view of GRS 1915+105
• A 2.4 - 12 microns spectrophotometric study with ISO of Cygnus X-3 in quiescence

Cited by in corpus (8)

• GRS 1915+105 and the Disc-Jet Coupling in Accreting Black Hole Systems
• Simultaneous multi-wavelength observations of GRS 1915+105
• On the optical extinction and distance of GRS 1915+105
• Long-term multi-wavelength studies of GRS 1915+105 I. A high-energy and mid-infrared focus with RXTE, INTEGRAL, and Spitzer
• ALMA/NICER observations of GRS 1915+105 indicate a return to a hard state
• Connection between accretion disk and superluminal radio jets and the role of radio plateau state in GRS 1915+105
• Observations of Rapid Disk-Jet Interaction in the Microquasar GRS 1915+105
• Is the plateau state in GRS 1915+105 equivalent to canonical hard states?