{
  "id": "2109.12007",
  "version": "v1",
  "published": "2021-09-24T15:02:19.000Z",
  "updated": "2021-09-24T15:02:19.000Z",
  "title": "The Thousand-Pulsar-Array programme on MeerKAT: -- VI. Pulse widths of a large and diverse sample of radio pulsars",
  "authors": [
    "B. Posselt",
    "A. Karastergiou",
    "S. Johnston",
    "A. Parthasarathy",
    "M. J. Keith",
    "L. S. Oswald",
    "X. Song",
    "P. Weltevrede",
    "E. D. Barr",
    "S. Buchner",
    "M. Geyer",
    "M. Kramer",
    "D. J. Reardon",
    "M. Serylak",
    "R. M. Shannon",
    "R. Spiewak",
    "V. Venkatraman Krishnan"
  ],
  "comment": "Accepted for publication in MNRAS. 20 pages, 19 figures, 7 tables",
  "doi": "10.1093/mnras/stab2775",
  "categories": [
    "astro-ph.HE",
    "astro-ph.SR"
  ],
  "abstract": "We present pulse width measurements for a sample of radio pulsars observed with the MeerKAT telescope as part of the Thousand-Pulsar-Array (TPA) programme in the MeerTime project. For a centre frequency of 1284 MHz, we obtain 762 $W_{10}$ measurements across the total bandwidth of 775 MHz, where $W_{10}$ is the width at the 10% level of the pulse peak. We also measure about 400 $W_{10}$ values in each of the four or eight frequency sub-bands. Assuming, the width is a function of the rotation period P, this relationship can be described with a power law with power law index $\\mu=-0.29\\pm 0.03$. However, using orthogonal distance regression, we determine a steeper power law with $\\mu=-0.63\\pm 0.06$. A density plot of the period-width data reveals such a fit to align well with the contours of highest density. Building on a previous population synthesis model, we obtain population-based estimates of the obliquity of the magnetic axis with respect to the rotation axis for our pulsars. Investigating the width changes over frequency, we unambiguously identify a group of pulsars that have width broadening at higher frequencies. The measured width changes show a monotonic behaviour with frequency for the whole TPA pulsar population, whether the pulses are becoming narrower or broader with increasing frequency. We exclude a sensitivity bias, scattering and noticeable differences in the pulse component numbers as explanations for these width changes, and attempt an explanation using a qualitative model of five contributing Gaussian pulse components with flux density spectra that depend on their rotational phase.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-09-24T15:02:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "radio pulsars",
      "pulse width",
      "thousand-pulsar-array programme",
      "diverse sample",
      "width changes"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 20,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}