Probing galaxy halos using background polarized radio sources
Ladda ner
Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Physics and astronomy (MPPAS), MSc
Publicerad
2016
Författare
Nilsson, Anton
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Linearly polarized radio emission from synchrotron sources undergoes Faraday rotation when passing through a magneto-ionized medium. This might be used to search for evidence of ionized halos around galaxies, using polarized radio sources as a probe. In this thesis I analyze the polarization properties of background radio sources from the Taylor et al. (2009) catalog based on observations with the Very Large Array, and correlate these to the angular separation between the radio sources and foreground galaxies. I find a decrease in the amount of polarized radio sources near the galaxies, interpreting this as radio sources being depolarized by galaxy halos. I also investigate searching for polarization in data from the Low Frequency Array (LOFAR). To this end, I reanalyze the observation of the M51 field by Mulcahy et al. (2014), focusing on the background radio sources in the field. I find several polarized sources, many of which contain complex polarization.
Beskrivning
Ämne/nyckelord
Fysik , Grundläggande vetenskaper , Astronomi, astrofysik och kosmologi , Extragalaktisk astronomi , Physical Sciences , Basic Sciences , Astronomy, Astrophysics and Cosmology , Extragalactical astronomy