A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity

Ma YK, Mao SA, Stil J, Basu A, West J, Heiles C, Hill AS, Betti SK (2019)
Monthly Notices of the Royal Astronomical Society 487(3): 3432-3453.

Zeitschriftenaufsatz | Veröffentlicht | Englisch
 
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Abstract / Bemerkung
The NRAO VLA Sky Survey (NVSS) rotation measure (RM) catalogue is invaluable for the study of cosmic magnetism, However, the RM values reported in it can be affected by n: r ambiguity, resulting in deviations of the reported RM from the true values by multiples of 652.9 rad in 2, We therefore set off to observationally constrain the fraction of sources in the RM catalogue affected by this ambiguity. New broad-band spectro-polarimetric observations were performed with the Karl G, Jansky Very Large Array (VLA) at 1-2 GH.z, with 23 n7 ambiguity candidates selected by their peculiarly high IRMI values. We identified nine sources with erroneous RM values due to T/7-ambiguity and 11 with reliable RM values, In addition, we found two sources to be unpolarized and one source to be inconsistent with neither rrr ambiguity nor reliable RM cases. By comparing the statistical distributions of the above two main classes, we devised a measure of how much a source's RM deviates from that of its neighbours: A/o-, which we found to be a good diagnostic of 1.77-ambiguity. With this, we estimate that there are at least 50 sources affected by run,-ambiguity among the 37 543 sources in the catalogue. Finally, we explored the Faraday complexities of our sources revealed by our broad-band observations.
Stichworte
ISM: magnetic fields; galaxies: active; galaxies: magnetic fields; radio; continuum: galaxies
Erscheinungsjahr
2019
Zeitschriftentitel
Monthly Notices of the Royal Astronomical Society
Band
487
Ausgabe
3
Seite(n)
3432-3453
ISSN
0035-8711
eISSN
1365-2966
Page URI
https://pub.uni-bielefeld.de/record/2936924

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Ma YK, Mao SA, Stil J, et al. A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity. Monthly Notices of the Royal Astronomical Society . 2019;487(3):3432-3453.
Ma, Y. K., Mao, S. A., Stil, J., Basu, A., West, J., Heiles, C., Hill, A. S., et al. (2019). A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity. Monthly Notices of the Royal Astronomical Society , 487(3), 3432-3453. doi:10.1093/mnras/stz1325
Ma, Y. K., Mao, S. A., Stil, J., Basu, A., West, J., Heiles, C., Hill, A. S., and Betti, S. K. (2019). A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity. Monthly Notices of the Royal Astronomical Society 487, 3432-3453.
Ma, Y.K., et al., 2019. A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity. Monthly Notices of the Royal Astronomical Society , 487(3), p 3432-3453.
Y.K. Ma, et al., “A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity”, Monthly Notices of the Royal Astronomical Society , vol. 487, 2019, pp. 3432-3453.
Ma, Y.K., Mao, S.A., Stil, J., Basu, A., West, J., Heiles, C., Hill, A.S., Betti, S.K.: A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity. Monthly Notices of the Royal Astronomical Society . 487, 3432-3453 (2019).
Ma, Yik Ki, Mao, S. A., Stil, Jeroen, Basu, Aritra, West, Jennifer, Heiles, Carl, Hill, Alex S., and Betti, S. K. “A broad-band spectro-polarimetric view of the NVSS rotation measure catalogue I. Breaking the n pi-ambiguity”. Monthly Notices of the Royal Astronomical Society 487.3 (2019): 3432-3453.