Year: 2015
Type: article
Abstract: The stages before the formation of stars in molecular clouds are poorly understood. Insights can be gained by studying the properties of quiescent clouds, such as their magnetic field structure. The plane-of-the-sky orientation of the field can be traced by polarized starlight. We present the first extended, wide-field (∼10 deg2) map of the Polaris Flare cloud in dust-absorption induced optical polarization of background stars, using the Robotic Polarimeter (RoboPol) polarimeter at the Skinakas Observatory. This is the first application of the wide-field imaging capabilities of RoboPol. The data were taken in the R band and analysed with the automated reduction pipeline of the instrument. We present in detail optimizations in the reduction pipeline specific to wide-field observations. Our analysis resulted in reliable measurements of 641 stars with median fractional linear polarization 1.3 per cent. The projected magnetic field shows a large-scale ordered pattern. At high longitudes it appears to align with faint striations seen in the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) map of dust emission (250 μm), while in the central 4–5 deg2 it shows an eddy-like feature. The overall polarization pattern we obtain is in good agreement with large-scale measurements by Planck of the dust emission polarization in the same area of the sky.
Authors: G. Panopoulou, K. Tassis, D. Blinov, V. Pavlidou, O. G. King, E. Paleologou, A. Ramaprakash, E. Angelakis, M. Baloković, H. K. Das, R. Feiler, T. Hovatta, P. Khodade, S. Kiehlmann, A. Kus, N. Kylafis, I. Liodakis, A. Mahabal, D. Modi, I. Myserlis, I. Papadakis, I. Papamastorakis, B. Pazderska, E. Pazderski, T. J. Pearson, C. Rajarshi, A. C. S. Readhead, P. Reig, J. A. Zensus
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, National Aeronautics and Space Administration, California Institute of Technology, International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, European Commission, Academy of Finland, KU Leuven, University of Crete, Max-Planck-Institut für Astronomie, Jet Propulsion Laboratory, Key Programme, European Social Fund
Awards: G1566079390, G2325242462, The Radio-Fermi Connection: A Critical Study of Relativistic Jets, Unveiling the Physics of the Most Active of Galaxies:
Using Blazars as Laboratories to Study Supermassive Black Holes and Relativistic Jets, Onset of Star Formation: Connecting Theory and Observations, G7973493166
OpenAlex ID: W2147228772