Polarization and photometric observations of the gamma-ray blazar PG 1553+113

• Published in: Astronomy and astrophysics (Berlin) Vol. 531; p. A38
• Main Authors: Andruchow, I., Combi, J. A., Muñoz-Arjonilla, A. J., Romero, G. E., Cellone, S. A., Martí, J.
• Format: Journal Article
• Language: English
• Published: Les Ulis EDP Sciences 01.07.2011
• Subjects: Astronomy; BL Lacertae objects: individual: PG 1553+113; Earth, ocean, space; Exact sciences and technology; polarization; Finding charts; Photometric observation; Variability; BL Lacertae objects: individual: PG 1553+113; Blazar; BL Lacertae objects; Gamma radiation; Cosmic radio sources; Linear polarization; polarization; Position angle; Polarimetry; Very high energy; Photometry
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/201016009

We present the results of an observational photo-polarimetry campaign of the blazar PG 1553+113 at optical wavelengths. The blazar was recently detected at very high energies (>100 GeV) by the HESS and MAGIC γ-ray Cherenkov telescopes. Our high-temporal resolution data show significant variations in the linear polarization percentage and position angle at inter-night time-scales, while at shorter (intra-night) time-scales both parameters varied less significantly, if at all. Changes in the polarization angle seem to be common in γ-ray emitting blazars. Simultaneous differential photometry (through the B and R bands) shows no significant variability in the total optical flux. We provide B and R magnitudes, along with a finding chart, for a set of field stars suitable for differential photometry.