the recent detection of a low-mass x-ray binary (lmxb) at 10mu has lead to new insights in the physical nature of the mass flow and accretion disk in these systems (van paradijs et al. 1994). the standard model of x-ray heating of the disk fails to account for the observed 10mu flux by at least two orders of magnitude. the current model is that the 10mu flux is the result of free-free emission produced in an x-ray induced wind from the accretion disk. the implication of this interpretation is that the mass-loss rate is much larger than the rate at which matter accretes onto the central compact object. the exciting consequence of this is that the usual estimates of the lifetimes of lmxbs may be substantial overestimates. correspondingly, the birth rate required to explain the observed lmxb population should be raised by about an order of magnitude. these disk winds may therefore contribute to the solution of the long-standing birth-rate problem, i.e. the observed discrepancy between the birth rates of lmxbs and their descendants, the binary millisecond pulsars. to investigate whether this is the correct interpretation we propose to study the infrared continuum distribution of a number of x-ray bright lmxbs. the continuum flux is predicted to have only a small dependence on wavelength; therefore we want to extent the measurements towards longer wavelengths. the presence of a disk wind can only be detected in the near-infrared wavelength region, since at shorter wavelengths the accretion disk dominates and at longer wavelengths optical-depth effects prohibit the detection of these winds. iso provides a unique opportunity to prove (or disprove) our interpretation.
Instrument
CAM01 , PHT03 , PHT32 , PHT40
Temporal Coverage
1996-11-18T03:33:36Z/1997-09-22T19:46:45Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
