Open AccessConstraints on jet X‐ray emission in low/hard‐state X‐ray binaries
Author(s) -
Maccarone Thomas J.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2005.00047.x
Subject(s) - physics , neutron star , astrophysics , luminosity , black hole (networking) , accretion (finance) , compact star , jet (fluid) , spectral line , stars , scaling , astronomy , galaxy , computer network , routing protocol , routing (electronic design automation) , geometry , mathematics , computer science , thermodynamics , link state routing protocol
We show that the similarities between the X‐ray properties of low‐luminosity accreting black holes and accreting neutron stars, combined with the differences in their radio properties, argue that the X‐rays from these systems are unlikely to be formed in the relativistic jets. Specifically, the spectra of extreme island‐state neutron stars and low/hard‐state black holes are known to be quite similar, while the power spectra from these systems are known to show only minor differences beyond what would be expected from scaling the characteristic variability frequencies by the mass of the compact object. The spectral and temporal similarities thus imply a common emission mechanism that has only minor deviations from having all key parameters scaling linearly with the mass of the compact object, while we show that this is inconsistent with the observations that the radio powers of neutron stars are typically about 30 times lower than those of black holes at the same X‐ray luminosity. We also show that an abrupt luminosity change would be expected when a system makes a spectral state transition from a radiatively inefficient jet‐dominated accretion flow to a thin disc‐dominated flow, but that such a change is not seen.