@article{83b46861fc1349c59e397de10e4960b2,
title = "Long-term variability of a black widow{\textquoteright}s eclipses – A decade of PSR J2051−0827",
abstract = "In this paper we report on ∼ 10 yr of observations of PSR J2051−0827, at radio frequencies in the range 110–4032 MHz. We investigate the eclipse phenomena of this black widow pulsar using model fits of increased dispersion and scattering of the pulsed radio emission as it traverses the eclipse medium. These model fits reveal variability in dispersion features on time-scales as short as the orbital period, and previously unknown trends on time-scales of months–years. No clear patterns are found between the low-frequency eclipse widths, orbital period variations, and trends in the intrabinary material density. Using polarization calibrated observations we present the first available limits on the strength of magnetic fields within the eclipse region of this system; the average line of sight field is constrained to be 10−4 G ≲ B|| ≲ 102 G, while for the case of a field directed near-perpendicular to the line of sight we find B ≲ 0.3 G. Depolarization of the linearly polarized pulses during the eclipse is detected and attributed to rapid rotation measure fluctuations of σRM ≳ 100 rad m−2 along, or across, the line of sights averaged over during a subintegration. The results are considered in the context of eclipse mechanisms, and we find scattering and/or cyclotron absorption provide the most promising explanation, while dispersion smearing is conclusively ruled out. Finally, we estimate the mass-loss rate from the companion to be M C ∼ 10−12 M yr−1 , suggesting that the companion will not be fully evaporated on any reasonable time-scale",
keywords = "Binaries: eclipsing, Plasmas, Pulsars: individual: PSR J2051-0827, Scattering, Stars: mass-loss",
author = "Polzin, {E. J.} and Breton, {R. P.} and Stappers, {B. W.} and B. Bhattacharyya and Janssen, {G. H.} and S. Os{\l}owski and Roberts, {M. S.E.} and C. Sobey",
note = "Funding Information: The Westerbork Synthesis Radio Telescope is operated by the ASTRON (Netherlands Institute for Radio Astronomy) with support from the Netherlands Foundation for Scientific Research (NWO). Funding Information: EJP acknowledges support from a UK Science and Technology Facilities Council studentship. RPB acknowledges support from the European Research Council under the European Union{\textquoteright}s Horizon 2020 research and innovation programme (grant agreement No. 715051; Spiders). SO acknowledges Australian Research Council grant FL150100148. Funding Information: The Parkes radio telescope is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. Funding Information: EJP would like to thank Simon Johnston and James Green for helping with planning and observing with the Parkes telescope, and Andrew Lyne and Mitchell Mickaliger for their work on recent, dedicated Lovell observations. This paper is based (in part) on data obtained with the International LOFAR Telescope (ILT). LOFAR is the Low Frequency Array designed and constructed by ASTRON. It has observing, data processing, and data storage facilities in several countries, that are owned by various parties (each with their own funding sources), and that are collectively operated by the ILT foundation under a joint scientific policy. The ILT resources have benefitted from the following recent major funding sources: CNRS-INSU, Observatoire de Paris and Universit? d?Orl?ans, France; BMBF, MIWF-NRW, MPG, Germany; Science Foundation Ireland (SFI), Department of Business, Enterprise and Innovation (DBEI), Ireland;NWO, The Netherlands; The Science and Technology Facilities Council, UK; Ministry of Science and Higher Education, Poland. The Westerbork Synthesis Radio Telescope is operated by the ASTRON (Netherlands Institute for Radio Astronomy) with support from the Netherlands Foundation for Scientific Research (NWO). The Parkes radio telescope is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. Pulsar research at Jodrell Bank Centre for Astrophysics and Jodrell Bank Observatory is supported by a consolidated grant from the UK Science and Technology Facilities Council (STFC). We thank the staff of the GMRT that made the observations possible. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. EJP acknowledges support from a UK Science and Technology Facilities Council studentship. RPB acknowledges support from the European Research Council under the European Union?s Horizon 2020 research and innovation programme (grant agreement No. 715051; Spiders). SO acknowledges Australian Research Council grant FL150100148. Funding Information: Pulsar research at Jodrell Bank Centre for Astrophysics and Jodrell Bank Observatory is supported by a consolidated grant from the UK Science and Technology Facilities Council (STFC). Funding Information: This paper is based (in part) on data obtained with the International LOFAR Telescope (ILT). LOFAR is the Low Frequency Array designed and constructed by ASTRON. It has observing, data processing, and data storage facilities in several countries, that are owned by various parties (each with their own funding sources), and that are collectively operated by the ILT foundation under a joint scientific policy. The ILT resources have benefitted from the following recent major funding sources: CNRS-INSU, Observatoire de Paris and Universit{\'e} d{\textquoteright}Orl{\'e}ans, France; BMBF, MIWF-NRW, MPG, Germany; Science Foundation Ireland (SFI), Department of Business, Enterprise and Innovation (DBEI), Ireland;NWO, The Netherlands; The Science and Technology Facilities Council, UK; Ministry of Science and Higher Education, Poland. Publisher Copyright: {\textcopyright} 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society",
year = "2019",
month = jan,
day = "1",
doi = "10.1093/mnras/stz2579",
language = "English (US)",
volume = "490",
pages = "889--908",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "1",
}