Open AccessRadio‐emitting component kinematics in SS433
Author(s) -
Stirling A. M.,
Jowett F. H.,
Spencer R. E.,
Paragi Z.,
Ogley R. N.,
Cawthorne T. V.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05944.x
Subject(s) - physics , astrophysics , position angle , kinematics , precession , redshift , astronomy , galaxy , classical mechanics
SS433 is a galactic X‐ray binary source, variable across most wavelengths of observation. On arcsecond‐scales the radio emission is composed of a bright core and the famous bipolar ‘corkscrew’ radio jets. A series of MERLIN observations at 5 GHz were taken in 1991 December and 1992 January. The emission from the radio jet was categorized by replacing discrete features with Gaussian flux‐density profiles. These fitted components were used to derive proper motions, ejection position‐angles and ejection dates for evolving features in the jets. The observed component position‐angles and ejection dates were compared to those predicted by the kinematic model of epoch 1989. The position‐angle of the precession cone was refined to . A discrepancy was discovered in the observed precessional phase which was leading that of the kinematic model by 7–10 d. This observed discrepancy was in agreement with a transient deviation in precessional phase as measured by the redshifts of optical bullets at a similar time. Analysis of the proper motions of all the fitted components leads to a distance measurement of 4.61 ± 0.35 pc . A pair of symmetrically ejected knots with a velocity much lower than 0.26 c were also discovered. Their ejection time overlapped with a period of unusual Doppler shift residuals and fragmentation of optical bullets. These events may represent the first evidence for an interaction between radio components and optical bullets.