TY - JOUR
T1 - The complete spectrum of the neutron star X-ray binary 4U 0614+091
AU - Migliari, S.
AU - Tomsick, J. A.
AU - Miller-Jones, J. C.A.
AU - Heinz, S.
AU - Hynes, R. I.
AU - Fender, R. P.
AU - Gallo, E.
AU - Jonker, P. G.
AU - MacCarone, T. J.
PY - 2010
Y1 - 2010
N2 - We observed the neutron star (NS) ultra-compact X-ray binary 4U 0614+091 quasi-simultaneously in the radio band (Very Large Array), mid-infrared (IR)/IR (Spitzer/Multiband Imaging Photometer for Spitzer and Infrared Array Camera), near-IR/optical (Small and Moderate Aperture Research Telescope System), optical-UV (Swift/UV-Optical Telescope), soft and hard X-rays (Swift/X-ray Telescope and Rossi-X-ray Timing Explorer). The source was steadily in its "hard state." We detected the source in the whole range, for the first time in the radio band at 4.86 and 8.46GHz and in the mid-IR at 24 μm, up to 100 keV. The optically thick synchrotron spectrum of the jet is consistent with being flat from the radio to the mid-IR band. The flat jet spectrum breaks in the range ∼(1-4) × 1013Hz to an optically thin power-law synchrotron spectrum with spectral index ∼-0.5. These observations allow us to estimate a lower limit on the jet radiative power of 3 × 10 32 erg s-1 and a total jet power L J ∼ 1034μ-1 0.05 E 0.53 c erg s-1 (where E c is the high-energy cutoff of the synchrotron spectrum in eV and μ0.05 is the radiative efficiency in units of 0.05). The contemporaneous detection of the optically thin part of the compact jet and the X-ray tail above 30keV allows us to assess the contribution of the jet to the hard X-ray tail by synchrotron self-Compton (SSC) processes. We conclude that, for realistic jet size, boosting, viewing angle, and energy partition, the SSC emission alone, from the post-shock, accelerated, non-thermal population in the jet, is not a viable mechanism to explain the observed hard X-ray tail of the NS 4U 0614+091.
AB - We observed the neutron star (NS) ultra-compact X-ray binary 4U 0614+091 quasi-simultaneously in the radio band (Very Large Array), mid-infrared (IR)/IR (Spitzer/Multiband Imaging Photometer for Spitzer and Infrared Array Camera), near-IR/optical (Small and Moderate Aperture Research Telescope System), optical-UV (Swift/UV-Optical Telescope), soft and hard X-rays (Swift/X-ray Telescope and Rossi-X-ray Timing Explorer). The source was steadily in its "hard state." We detected the source in the whole range, for the first time in the radio band at 4.86 and 8.46GHz and in the mid-IR at 24 μm, up to 100 keV. The optically thick synchrotron spectrum of the jet is consistent with being flat from the radio to the mid-IR band. The flat jet spectrum breaks in the range ∼(1-4) × 1013Hz to an optically thin power-law synchrotron spectrum with spectral index ∼-0.5. These observations allow us to estimate a lower limit on the jet radiative power of 3 × 10 32 erg s-1 and a total jet power L J ∼ 1034μ-1 0.05 E 0.53 c erg s-1 (where E c is the high-energy cutoff of the synchrotron spectrum in eV and μ0.05 is the radiative efficiency in units of 0.05). The contemporaneous detection of the optically thin part of the compact jet and the X-ray tail above 30keV allows us to assess the contribution of the jet to the hard X-ray tail by synchrotron self-Compton (SSC) processes. We conclude that, for realistic jet size, boosting, viewing angle, and energy partition, the SSC emission alone, from the post-shock, accelerated, non-thermal population in the jet, is not a viable mechanism to explain the observed hard X-ray tail of the NS 4U 0614+091.
KW - Accretion, accretion disks
KW - ISM: jets and outflows
KW - Infrared: general
KW - X-rays: binaries
UR - http://www.scopus.com/inward/record.url?scp=76949092162&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/710/1/117
DO - 10.1088/0004-637X/710/1/117
M3 - Article
AN - SCOPUS:76949092162
VL - 710
SP - 117
EP - 124
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
ER -