Jet Velocity in SS 433: Its Anticorrelation with Precession-Cone Angle and Dependence on Orbital Phase

Blundell, Katherine M.; Bowler, M.G.

doi:10.1086/429663

Cited by 31 publications

(66 citation statements)

References 11 publications

(20 reference statements)

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“…These newly discovered effects reproduced well the correlations between observed excursions ∆z + and ∆z − (Fig. 6 in Blundell & Bowler 2005). These correlations are quite independent of any assumption of symmetry, even though the model which explained them was not.…”

Section: Introductionsupporting

confidence: 77%

“…Superimposed on the simplest kinematic model is the effect of nutation of (presumably) the accretion disc, known as nodding . Accumulated data on the Doppler shifts of the Hα lines dating back over 25 years have been reviewed by Eikenberry et al (2001) and more recently by Blundell & Bowler (2005). It has long been clear that the redshifts exhibit fluctuations from the model predictions and that there is a fair degree of symmetry in those fluctuations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fluctuations and symmetry in the speed and direction of the jets of SS 433 on different timescales

Blundell¹,

Bowler²,

Schmidtobreick

2007

A&A

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Context. The Galactic microquasar SS 433 launches oppositely-directed plasma jets at speeds approximately a quarter of the speed of light along an axis which precesses, tracing out a cone of polar angle 20 degrees. Both the speed and direction of launch of the bolides that comprise the jets exhibit small fluctuations. Aims. To present new results on variations in speed and direction of successive bolides over periods of one day or less and the range in speed and direction exhibited by material within individual bolides. To present the expansion rate of bolides revealed by optical line broadening. To integrate these results with earlier data sensitive to fluctuations and symmetry over longer timescales. Methods. New high resolution spectra, taken with a 3.6-m telescope almost nightly over 0.4 of a precession cycle, are analysed in terms of fluctuations in the properties of the ejecta, by comparing the redshift data with predictions for small departures from the simple kinematic model. The variations of redshifts of the jets within a day are studied, in addition to the longer term variations of the daily averaged properties. Results. (i) These data exhibit multiple ejections within most 24-h periods and, throughout the duration of the observing campaign, the weighted means of the individual bolides, in both the red jet and the blue jet, clearly exhibit the pronounced nodding known in this system; (ii) we present further evidence for a 13-day periodicity in the jet speed, and show this cannot be dominated by Doppler shifts from orbital motion; (iii) we show the phase of this peak jet speed has shifted by a quarter of a cycle in the last quarter-century; (iv) we show that the two jets ejected by SS 433 are highly symmetric on timescales measured thus far; (v) we demonstrate that the anti-correlation between variations in direction and in speed is not an artifact of an assumption of symmetry; (vi) we show that a recently proposed mechanism (Begelman et al. 2006, MNRAS, 370, 399) for varying the ejection speed and anti-correlating it with polar angle variations is ruled out; (vii) the speed of expansion of the plasma bolides in the jets is approximately 0.0024 c. Conclusions. These novel data carry a clear signature of speed variations. They have a simple and natural interpretation in terms of both angular and speed fluctuations which are identical on average in the two jets. They complement archival optical data and recent radio imaging.

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Section: Introductionsupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Fluctuations and symmetry in the speed and direction of the jets of SS 433 on different timescales

Blundell¹,

Bowler²,

Schmidtobreick

2007

A&A

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“…Jet precession may occur in a variety of astrophysical objects, including low-mass star formation in the Galaxy (L1157 Gueth et al 1996;Kwon et al 2015;NGC 1333-IRAS4A Santangelo et al 2015L 1551IRS 5 Fridlund & Liseau 1994IRAS 16293-2422Kristensen et al 2013); Galactic micro-quasars (SS433 Blundell & Bowler 2005and 1E 1740.7-2942Luque-Escamilla et al 2015, and AGN radio jets (e.g. Veilleux et al 1993;Steffen 1997;Martí-Vidal et al 2011;Pyrzas et al 2015).…”

Section: Origin Of Precessionmentioning

confidence: 99%

A precessing molecular jet signaling an obscured, growing supermassive black hole in NGC 1377?

Aalto

Costagliola

Müller

et al. 2016

A&A

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With high resolution (0. 25 × 0. 18) ALMA CO 3−2 (345 GHz) observations of the nearby (D = 21 Mpc, 1 = 102 pc), extremely radio-quiet galaxy NGC 1377, we have discovered a high-velocity, very collimated nuclear outflow which we interpret as a molecular jet with a projected length of ±150 pc. The launch region is unresolved and lies inside a radius r < 10 pc. Along the jet axis we find strong velocity reversals where the projected velocity swings from −150 km s −1 to +150 km s −1 . A simple model of a molecular jet precessing around an axis close to the plane of the sky can reproduce the observations. The velocity of the outflowing gas is difficult to constrain due to the velocity reversals but we estimate it to be between 240 and 850 km s −1 and the jet to precess with a period P = 0.3−1.1 Myr. The CO emission is clumpy along the jet and the total molecular mass in the high-velocity (±(60 to 150 km s −1 )) gas lies between 2 × 10 6 M (light jet) and 2 × 10 7 M (massive jet). There is also CO emission extending along the minor axis of NGC 1377. It holds >40% of the flux in NGC 1377 and may be a slower, wide-angle molecular outflow which is partially entrained by the molecular jet. We discuss the driving mechanism of the molecular jet and suggest that it is either powered by a (faint) radio jet or by an accretion disk-wind similar to those found towards protostars. It seems unlikely that a massive jet could have been driven out by the current level of nuclear activity which should then have undergone rapid quenching. The light jet would only have expelled 10% of the inner gas and may facilitate nuclear activity instead of suppressing it. The nucleus of NGC 1377 harbours intense embedded activity and we detect emission from vibrationally excited HCN J = 4−3 ν 2 = 1 f which is consistent with hot gas and dust. We find large columns of H 2 in the centre of NGC 1377 which may be a sign of a high rate of recent gas infall. The dynamical age of the molecular jet is short (<1 Myr), which could imply that it is young and consistent with the notion that NGC 1377 is caught in a transient phase of its evolution. However, further studies are required to determine the age of the molecular jet, its mass and the role it is playing in the growth of the nucleus of NGC 1377.

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“…The precession and nutation periods were fixed, along with the nutation phase and amplitude and parameters associated with the slight velocity variation with orbital period found by Blundell & Bowler (2005) (observable in the panel showing β in Fig. 10).…”

Section: X-ray Doppler Shiftsmentioning

confidence: 99%

Multiwavelength Observations of the Ss 433 Jets

Marshall

Canizares

Hillwig

et al. 2013

ApJ

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We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and VLBA observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 10 14 cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise > 50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to 2 × 10 12 cm. The base jet density is in the range 10 10−13 cm −3 , in contrast to our previous estimate based on the Si xiii triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

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Jet Velocity in SS 433: Its Anticorrelation with Precession-Cone Angle and Dependence on Orbital Phase

Cited by 31 publications

References 11 publications

Fluctuations and symmetry in the speed and direction of the jets of SS 433 on different timescales

Fluctuations and symmetry in the speed and direction of the jets of SS 433 on different timescales

A precessing molecular jet signaling an obscured, growing supermassive black hole in NGC 1377?

Multiwavelength Observations of the Ss 433 Jets

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