Cohen, Marshall H. (2017) OJ 287 as a Rotating Helix. Galaxies, 5 (1). Art. No. 12. ISSN 2075-4434. https://resolver.caltech.edu/CaltechAUTHORS:20180430-101113523
![[img]](https://authors.library.caltech.edu/style/images/fileicons/application_pdf.png) |
PDF
- Published Version
Creative Commons Attribution. 1910Kb |
|
PDF (Addendum)
- Erratum
Creative Commons Attribution. 162Kb |
Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20180430-101113523
Abstract
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.
| Item Type: | Article | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Related URLs: |
| |||||||||
| Additional Information: | © 2017 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( http://creativecommons.org/licenses/by/4.0/). Received: 6 September 2016 / Revised: 9 January 2017 / Accepted: 16 January 2017 / Published: 8 February 2017 (This article belongs to the Special Issue Blazars through Sharp Multi-wavelength Eyes) I am grateful to A. Pushkarev for calculating the ridgelines, and to the MOJAVE team for advice and suggestions. The authors declare no conflict of interest. | |||||||||
| Errata: | In an earlier paper it was erroneously stated that the inner jet of OJ 287 has a right-hand helical structure. In this addendum we show that the observations underlying this statement are ambiguous, and that they cannot determine the rotation sense. | |||||||||
| Group: | Astronomy Department | |||||||||
| Subject Keywords: | BL Lacertae objects: individual (OJ 287); galaxies: active; galaxies: jets; magnetohydrodynamics (MHD); waves | |||||||||
| Issue or Number: | 1 | |||||||||
| Record Number: | CaltechAUTHORS:20180430-101113523 | |||||||||
| Persistent URL: | https://resolver.caltech.edu/CaltechAUTHORS:20180430-101113523 | |||||||||
| Official Citation: | Cohen, M.H. OJ 287 as a Rotating Helix. Galaxies 2017, 5, 12. | |||||||||
| Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | |||||||||
| ID Code: | 86119 | |||||||||
| Collection: | CaltechAUTHORS | |||||||||
| Deposited By: | George Porter | |||||||||
| Deposited On: | 30 Apr 2018 21:22 | |||||||||
| Last Modified: | 03 Oct 2019 19:39 |
Repository Staff Only: item control page
