OJ 287 as a Rotating Helix

Galaxies

Marshall H. Cohen¹ 

[1] Department of Astronomy, California Institute of Technology, Pasadena, CA 91125, USA;

关键词: BL Lacertae objects: individual (OJ 287);    galaxies: active;    galaxies: jets;    magnetohydrodynamics (MHD);    waves;   

DOI  :  10.3390/galaxies5010012

来源: DOAJ

【 摘 要 】

We present preliminary data from high-cadence 15-GHz VLBA images of OJ 287 from 1995 to 2015. The ridgelines suggest that the jet is rotating, perhaps with a period of∼30 years. The EVPA of the core rotated by 240° in 2001–2002 and decreased slowly after that. The inner jet apparently moved to a new direction after the rotation,as shown by the emergence of a new component at a new PA at 43 GHz, in 2004. This was presaged by a strong rise in the flux density of the core, and then its sudden fall as the new component was identified. The equivalent sequence of events took place about 5 years later at 15 GHz, but in addition the core EVPA had a step in 2006 and moved to be aligned with the new 43-GHz component. The 15-GHz core became optically thin in 2006, but the angular resolution was insufficient to separate the new component from the core until 2010

【 授权许可】

Unknown