VLBI observations of a radio flare of Circinus X-1

Preston, R. A.; Morabito, D. D.; Wehrle, A. E.; Jauncey, D. L.; Batty, M; Haynes, R. F.; Wright, A. E.; Nicolson, G. D.

doi:10.1086/184022

Cited by 27 publications

(24 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even though the radio monitoring of Cir X‐1 was sparse in the last three decades, apparently there is a secular decrease in the radio flux levels measured in the active as well as in the quiescent states, with short periods of enhanced activity (Whelan et al 1977; Haynes et al 1978; Nicolson et al 1980; Preston et al 1983; Stewart et al 1991, 1993; Fender 1997; Fender et al 1998, 2005). The ASM/ Rossi X‐ray Timing Explorer ( RXTE ) 2 data from the last ∼10 yr show a similar behaviour in X‐ray band.…”

Section: Observationsmentioning

confidence: 99%

The large-scale jet-powered radio nebula of Circinus X-1

Tudose

Fender

Kaiser

et al. 2006

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present multi-epoch observations of the radio nebula around the neutron star X-ray binary Circinus X-1 made at 1.4 and 2.5 GHz with the Australia Telescope Compact Array between October 2000 and September 2004. The nebula can be seen as a result of the interaction between the jet from the system and the interstellar medium and it is likely that we are actually looking toward the central X-ray binary system through the jet-powered radio lobe. The study of the nebula thus offers a unique opportunity to estimate for the first time using calorimetry the energetics of a jet from an object clearly identified as a neutron star. An extensive discussion on the energetics of the complex is presented: a first approach is based on the minimum energy estimation, while a second one employs a self-similar model of the interaction between the jets and the surrounding medium. The results suggest an age for the nebula of \leq 10^5 years and a corresponding time-averaged jet power \geq 10^{35} erg s^{-1}. During periodic flaring episodes, the instantaneous jet power may reach values of similar magnitude to the X-ray luminosity.Comment: Accepted to MNRA

show abstract

Section: Observationsmentioning

confidence: 99%

The large-scale jet-powered radio nebula of Circinus X-1

Tudose

Fender

Kaiser

et al. 2006

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…): [214]; high kick velocity: [1266]; high eccentricity: [636,972,1266]; VLBI obs. : [1055]; model: [942]. P os.…”

mentioning

confidence: 99%

A catalogue of low-mass X-ray binaries

Liu

Paradijs

Heuvel

2001

A&A

209

206

View full text Add to dashboard Cite

Abstract. We present a catalogue of low-mass X-ray binaries. The catalogue is an updated version of the catalogue of van Paradijs (1995). This new catalogue contains 150 sources, 31 new low-mass X-ray binaries in addition to the 119 sources listed in van Paradijs' catalogue. The aim of this catalogue is to help the reader gain easy access to the recent literature (up to about August 2000) on individual sources, and to provide of some basic information on the X-ray sources and their counterparts in other wavelength ranges (UV, optical, IR, and radio). In cases where there is some doubt about the low-mass nature of the X-ray binary, this is mentioned. In an appendix we list the Anomalous X-ray Pulsars (AXPs), which nowadays are no longer thought to be low-mass X-ray binaries.

show abstract

“…For comparison, we find the size of the compact source to be 60 ± 15 mas at 1.6 GHz and <60 mas at 8.4 GHz. We find that the correlated flux density at 1.6 GHz on short baselines is 11 mJy and at 8.4 GHz is 5 mJy, significantly weaker than seen by Preston et al (1983) in the 1980s.…”

Section: Discussionmentioning

confidence: 49%

“…An arcmin‐scale radio nebula surrounds Cir X‐1 (Tudose et al 2006; Stewart et al 1993; Haynes et al 1986), powered by an arcsec‐scale jet originating at the binary system and aligned with our line of sight to within 5° (Fender et al 2004, 1998). The most compact radio structure in Cir X‐1, near the site of acceleration of the particles injected into the jet seen on larger scales, has been previously observed by Preston et al (1989, 1983) who undertook very long baseline interferometry (VLBI) observations at 2.3 GHz in pre‐flare and flaring states in 1980 and 1982, respectively. In both observations the flaring source was unresolved on the Tidbinbilla–Parkes baseline but completely resolved on the Australia–South Africa baseline.…”

Section: Introductionmentioning

confidence: 78%

“…The e‐VLBI observations described here took place between ∼12 and ∼70 h after the time of the predicted flare at 2007/03/23 01:31 ut (Nicolson 2007), with the compact source detected during all observations. The Preston et al (1983) 2.3‐GHz VLBI campaign was spread over the six‐day duration of a strong flare, and the variable component was detected during all of the observations, although no component was detected during the pre‐flare period. They set angular size limits of between 1.5 and 15 mas during both the 1980 and 1982 flares, and on each occasion detected no compact component during the pre‐flare period, implying a size of several hundred mas, or a compact component below their sensitivity limits.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Detection of compact radio emission from Circinus X-1 with the first Southern hemisphere e-VLBI experiment

Phillips

Deller

Amy

et al. 2007

Monthly Notices of the Royal Astronomical Society: Letters

Self Cite

View full text Add to dashboard Cite

Circinus X-1 has recently returned to a state of strong radio flaring. Here we report on the first VLBI observations, and detection, undertaken in the 25 years since the 1975-1985 period of strong recurrent flaring activity. We detected Circinus X-1 with the first observations conducted by a recently developed Southern hemisphere e-VLBI array, at both 1.6 and 8.4 GHz, over a three-day period. At 1.6 GHz, the compact source has a total flux density of 11 mJy and a size of 60 ± 15 mas (Gaussian model full width at half maximum). At 8.4 GHz, the compact source is less than 60 mas. The size variation with frequency is consistent with a broadened image due to scattering in the turbulent, ionized interstellar medium of our Galaxy. However, these size measurements appear inconsistent with the λ 2.2 variation expected for strong interstellar scattering and previous VLBI observations made at 2.3 GHz in the early 1980s. To explain this apparent inconsistency, we suggest that Circinus X-1 supports a weak, non-varying component of 35 mas extent (175 au at 5 kpc distance), corresponding to compact structure in the extended radio nebula. No significant variation in the flux density at 1.6 GHz is evident between two observations 24 h apart. No jet-like structures are evident on scales of tens of mas, simply a scatter broadened source, presumably coincident with the suggested neutron star in the binary system.

show abstract

VLBI observations of a radio flare of Circinus X-1

Cited by 27 publications

References 0 publications

The large-scale jet-powered radio nebula of Circinus X-1

The large-scale jet-powered radio nebula of Circinus X-1

A catalogue of low-mass X-ray binaries

Detection of compact radio emission from Circinus X-1 with the first Southern hemisphere e-VLBI experiment

Contact Info

Product

Resources

About