Slower Superluminal Velocity for the Quasar 1156 + 295
نویسنده
چکیده
As part of an ongoing effort to observe high energy γ-ray blazars with VLBI, we have produced 8 and 2 GHz VLBI images, at ten epochs spanning the years 1988 to 1996, of the quasar 1156+295. The VLBI data have been taken from the Washington VLBI correlator’s geodetic database. We have detected four components and have measured their apparent speeds to be 8.8 ± 2.3, 5.3 ± 1.1, 5.5 ± 0.9, and 3.5 ± 1.2 hc from the outermost component inwards. (H0 = 100h km s −1 Mpc, q0=0.5 throughout paper). These velocities contradict a previously published very high superluminal velocity of 26 hc for this source. Subject headings: Galaxies: Jets Galaxies: Quasars: Individual (1156+295) Radio Continuum: Galaxies
منابع مشابه
Overview and initial results of the very long baseline interferometry space observatory programme
High angular resolution images of extragalactic radio sources are being made with the Highly Advanced Laboratory for Communications and Astronomy (HALCA) satellite and ground-based radio telescopes as part of the Very Long Baseline Interferometry (VLBI) Space Observatory Programme (VSOP). VSOP observations at 1.6 and 5 gigahertz of the milli-arc-second-scale structure of radio quasars enable th...
متن کاملSerendipitous VLBI detection of rapid , large - amplitude , intraday variability in QSO 1156 + 295
Aims. We report a serendipitous detection of rapid, large amplitude flux density variations in the highly core-dominated, flat-spectrum radio quasar 1156+295 during an observing session at the Very Long Baseline Array (VLBA). Methods. The source was observed as a part of the MOJAVE survey programme with the VLBA at 15 GHz on February 5, 2007. Large amplitude variability in the correlated flux d...
متن کاملThe compact core - jet region of the superluminal quasar 3 C 216
Space very long baseline interferometry (VLBI) observations of the quasar 3C 216 with the VLBI Space Observatory Programme (VSOP) reveal that the parsec scale structure of the source can be well described by compact jet models developed for interpreting the core region of radio-loud active galactic nuclei (AGN). The measured brightness temperature of TB = 7.9 × 10 11 K is comparable to the inve...
متن کاملar X iv : a st ro - p h / 99 06 35 8 v 1 2 3 Ju n 19 99 Helical motions in the jet of blazar 1156 + 295
The blazar 1156+295 was observed by VLBA and EVN + MERLIN at 5 GHz in June 1996 and February 1997 respectively. The results show that the jet of the source has structural oscillations on the milliarcsecond scale and turns through a large angle to the direction of the arcsecond-scale extension. A helical jet model can explain most of the observed properties of the radio structure in 1156+295.
متن کاملLinear Accelerating Superluminal Motion Model
Accelerating superluminal motions were detected recently by multi-epoch Very Long Baseline Interferometry (VLBI) observations. Here, a Linear Accelerating Superluminal Motion (LASM) model is proposed to interpret the observed phenomena. The model provides a direct and accurate way to estimate the viewing angle of a relativistic jet. It also predicts that both Doppler boosting and deboosting eff...
متن کامل