Optical polarimetry of TXS 0506+056 (possible counterpart of IceCube-170922A)
ATel #11430; I. A. Steele, H. Jermak, C. Copperwheat (Liverpool JMU)
on 16 Mar 2018; 10:08 UT
Credential Certification: Iain Steele (iainsteele@mac.com)
Subjects: Optical, Gamma Ray, Neutrinos, Quasar
Referred to by ATel #: 11489
ATel #11419 reports enhanced Gamma Ray Activity of TXS 0506+056 detected by Fermi-LAT on 2018 March 13. A previous Fermi-LAT high state of this source in the period 2017 Sept 15-27 was potentially associated with the Ice Cube Neutrino detection 170922A (ATel #10791). TXS 0506+056 is a BL Lac object (e.g. ATel #10799) with redshift z=0.34 (Paiano et al, 2018, ApJ, 854, L32).
We obtained optical polarimetry of the BL Lac object on the night of 2018 March 14 using the RINGO3 polarimeter of the 2.0 metre Liverpool Telescope, La Palma. We find the polarisation is moderately strong (P~14%) at wavelengths roughly corresponding to the R and I bands. This is an increase from the R band polarisation P~8% reported in ATel #10844 from the Katana telescope at the time of the previous high state on 2017 Sept 30, although it is within the typical range of BL Lac optical polarisation values of 0-30% (see e.g. Figure 4 of Jermak et al, 2016, MNRAS, 462, 4267).
Liverpool Telescope
