{
  "id": "2104.00014",
  "version": "v1",
  "published": "2021-03-31T18:00:03.000Z",
  "updated": "2021-03-31T18:00:03.000Z",
  "title": "Evidence of TeV Halos Around Millisecond Pulsars",
  "authors": [
    "Dan Hooper",
    "Tim Linden"
  ],
  "comment": "8 pages, 5 figures",
  "categories": [
    "astro-ph.HE",
    "astro-ph.GA",
    "hep-ph"
  ],
  "abstract": "Using data from the HAWC gamma-ray Telescope, we have studied a sample of 37 millisecond pulsars (MSPs), selected for their spindown power and proximity. From among these MSP, we have identified four which favor the presence of very high-energy gamma-ray emission at a level of $(2\\Delta \\ln \\mathcal{L})^{1/2} \\ge 2.5$. Adopting a correlation between the spindown power and gamma-ray luminosity of each pulsar, we performed a stacked likelihood analysis of these 37 MSPs, finding that the data supports the conclusion that these sources emit very high-energy gamma-rays at a level of $(2\\Delta \\ln \\mathcal{L})^{1/2} = 4.24$. Among sets of randomly selected sky locations within HAWC's field-of-view, less than 1\\% of such realizations yielded such high statistical significance. Our analysis suggests that MSPs produce very high-energy gamma-ray emission with a similar efficiency to that observed from the Geminga TeV-halo, $\\eta_{\\rm MSP} = (0.39-1.08) \\times \\eta_{\\rm Geminga}$. This conclusion poses a significant challenge for pulsar interpretations of the Galactic Center gamma-ray excess, as it suggests that any population of MSPs potentially capable of producing the GeV excess would also produce TeV-scale emission in excess of that observed by HESS from this region. Future observations by CTA will be able to substantially clarify this situation.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-03-31T18:00:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "millisecond pulsars",
      "tev halos",
      "high-energy gamma-ray emission",
      "galactic center gamma-ray excess",
      "spindown power"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}