Spitzer reveals infrared optically thin synchrotron emission from the compact jet of the neutron star x-ray binary 4U 0614+091

S. Migliari, J. A. Tomsick, T. J. Maccarone, E. Gallo, R. P. Fender, G. Nelemans, Dave Russell

Research output: Contribution to journalArticle

Abstract

Spitzer observations of the neutron star (ultracompact) X-ray binary (XRB) 4U 0614+091 with the Infrared Array Camera reveal emission of nonthermal origin in the range 3.5-8 μm. The mid-infrared spectrum is well fit by a power law with spectral index of α = -0.57 ± 0.04 (where the flux density is Fv ∞ vα). Given the ultracompact nature of the binary system, we exclude the possibility that either the companion star or the accretion disk can be the origin of the observed emission. These observations represent the first spectral evidence for a compact jet in a low-luminosity neutron star XRB and furthermore of the presence, already observed in two black hole (BH) XRBs, of a "break" in the synchrotron spectrum of such compact jets. We can derive a firm upper limit on the break frequency of the spectrum of Vthin = 3.7 × 1013 Hz, which is lower than that observed in BH XRBs by at least a factor of 10. Assuming a high-energy cooling cutoff at ∼1 keV, we estimate a total (integrated up to X-rays) jet power to X-ray bolometric luminosity ratio of ∼5%, much lower than that inferred in BHs.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume643
Issue number1 II
DOIs
StatePublished - May 29 2006

Fingerprint

x ray binaries
neutron stars
synchrotrons
x rays
luminosity
companion stars
accretion disks
power law
infrared spectra
cut-off
flux density
cameras
accretion
cooling
estimates
energy

Keywords

  • Infrared: general
  • ISM: jets and outflows
  • Radiation mechanisms: nonthermal
  • X-rays: binaries

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Spitzer reveals infrared optically thin synchrotron emission from the compact jet of the neutron star x-ray binary 4U 0614+091. / Migliari, S.; Tomsick, J. A.; Maccarone, T. J.; Gallo, E.; Fender, R. P.; Nelemans, G.; Russell, Dave.

In: Astrophysical Journal, Vol. 643, No. 1 II, 29.05.2006.

Research output: Contribution to journalArticle

Migliari, S. ; Tomsick, J. A. ; Maccarone, T. J. ; Gallo, E. ; Fender, R. P. ; Nelemans, G. ; Russell, Dave. / Spitzer reveals infrared optically thin synchrotron emission from the compact jet of the neutron star x-ray binary 4U 0614+091. In: Astrophysical Journal. 2006 ; Vol. 643, No. 1 II.
@article{464fb74dd1f847faa7b4ed4c510e8904,
title = "Spitzer reveals infrared optically thin synchrotron emission from the compact jet of the neutron star x-ray binary 4U 0614+091",
abstract = "Spitzer observations of the neutron star (ultracompact) X-ray binary (XRB) 4U 0614+091 with the Infrared Array Camera reveal emission of nonthermal origin in the range 3.5-8 μm. The mid-infrared spectrum is well fit by a power law with spectral index of α = -0.57 ± 0.04 (where the flux density is Fv ∞ vα). Given the ultracompact nature of the binary system, we exclude the possibility that either the companion star or the accretion disk can be the origin of the observed emission. These observations represent the first spectral evidence for a compact jet in a low-luminosity neutron star XRB and furthermore of the presence, already observed in two black hole (BH) XRBs, of a {"}break{"} in the synchrotron spectrum of such compact jets. We can derive a firm upper limit on the break frequency of the spectrum of Vthin = 3.7 × 1013 Hz, which is lower than that observed in BH XRBs by at least a factor of 10. Assuming a high-energy cooling cutoff at ∼1 keV, we estimate a total (integrated up to X-rays) jet power to X-ray bolometric luminosity ratio of ∼5{\%}, much lower than that inferred in BHs.",
keywords = "Infrared: general, ISM: jets and outflows, Radiation mechanisms: nonthermal, X-rays: binaries",
author = "S. Migliari and Tomsick, {J. A.} and Maccarone, {T. J.} and E. Gallo and Fender, {R. P.} and G. Nelemans and Dave Russell",
year = "2006",
month = "5",
day = "29",
doi = "10.1086/505028",
language = "English (US)",
volume = "643",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1 II",

}

TY - JOUR

T1 - Spitzer reveals infrared optically thin synchrotron emission from the compact jet of the neutron star x-ray binary 4U 0614+091

AU - Migliari, S.

AU - Tomsick, J. A.

AU - Maccarone, T. J.

AU - Gallo, E.

AU - Fender, R. P.

AU - Nelemans, G.

AU - Russell, Dave

PY - 2006/5/29

Y1 - 2006/5/29

N2 - Spitzer observations of the neutron star (ultracompact) X-ray binary (XRB) 4U 0614+091 with the Infrared Array Camera reveal emission of nonthermal origin in the range 3.5-8 μm. The mid-infrared spectrum is well fit by a power law with spectral index of α = -0.57 ± 0.04 (where the flux density is Fv ∞ vα). Given the ultracompact nature of the binary system, we exclude the possibility that either the companion star or the accretion disk can be the origin of the observed emission. These observations represent the first spectral evidence for a compact jet in a low-luminosity neutron star XRB and furthermore of the presence, already observed in two black hole (BH) XRBs, of a "break" in the synchrotron spectrum of such compact jets. We can derive a firm upper limit on the break frequency of the spectrum of Vthin = 3.7 × 1013 Hz, which is lower than that observed in BH XRBs by at least a factor of 10. Assuming a high-energy cooling cutoff at ∼1 keV, we estimate a total (integrated up to X-rays) jet power to X-ray bolometric luminosity ratio of ∼5%, much lower than that inferred in BHs.

AB - Spitzer observations of the neutron star (ultracompact) X-ray binary (XRB) 4U 0614+091 with the Infrared Array Camera reveal emission of nonthermal origin in the range 3.5-8 μm. The mid-infrared spectrum is well fit by a power law with spectral index of α = -0.57 ± 0.04 (where the flux density is Fv ∞ vα). Given the ultracompact nature of the binary system, we exclude the possibility that either the companion star or the accretion disk can be the origin of the observed emission. These observations represent the first spectral evidence for a compact jet in a low-luminosity neutron star XRB and furthermore of the presence, already observed in two black hole (BH) XRBs, of a "break" in the synchrotron spectrum of such compact jets. We can derive a firm upper limit on the break frequency of the spectrum of Vthin = 3.7 × 1013 Hz, which is lower than that observed in BH XRBs by at least a factor of 10. Assuming a high-energy cooling cutoff at ∼1 keV, we estimate a total (integrated up to X-rays) jet power to X-ray bolometric luminosity ratio of ∼5%, much lower than that inferred in BHs.

KW - Infrared: general

KW - ISM: jets and outflows

KW - Radiation mechanisms: nonthermal

KW - X-rays: binaries

UR - http://www.scopus.com/inward/record.url?scp=33745870825&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33745870825&partnerID=8YFLogxK

U2 - 10.1086/505028

DO - 10.1086/505028

M3 - Article

AN - SCOPUS:33745870825

VL - 643

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 II

ER -