{
  "id": "1408.1699",
  "version": "v2",
  "published": "2014-08-07T20:00:06.000Z",
  "updated": "2015-04-08T22:00:35.000Z",
  "title": "Discovery of a 3.5 keV line in the Galactic Center and a Critical Look at the Origin of the Line Across Astronomical Targets",
  "authors": [
    "Tesla E. Jeltema",
    "Stefano Profumo"
  ],
  "comment": "v.2: significant additions and revisions, including new studies of the Tycho SNR, multi-temperature plasma models, systematic effects; conclusions substantially unchanged from v.1; accepted for publication in Monthly Notices of the Royal Astronomical Society",
  "categories": [
    "astro-ph.HE",
    "astro-ph.CO",
    "hep-ph"
  ],
  "abstract": "We examine the claimed excess X-ray line emission near 3.5 keV including both a new analysis of XMM-Newton observations of the Milky Way center and a reanalysis of the data on M~31 and clusters. In no case do we find conclusive evidence for an excess. In the case of the Galactic center we show that known plasma lines, including in particular K XVIII lines at 3.48 and 3.52 keV, provide a satisfactory fit to the XMM data. We estimate the expected flux of the K XVIII lines and find that the measured line flux falls squarely within the predicted range based on the brightness of other well-measured lines in the energy range of interest and on detailed multi-temperature plasma models. We then re-assess the evidence for excess emission from clusters of galaxies, allowing for systematic uncertainty in the expected flux from known plasma lines and additional uncertainty due to potential variation in the abundances of different elements. We find that no conclusive excess line emission can be advocated when considering systematic uncertainties in Perseus or in other clusters. We also re-analyze the XMM data for M~31 and find no statistically significant line emission near 3.5 keV to a level greater than one sigma. Finally, we analyze the Tycho supernova remnant, which shows similar plasma features to the sources above, but does not host any significant dark matter. We detect a 3.55 keV line from Tycho, which points to possible systematic effects in the flux determination of weak lines, or to relative elemental abundances vastly different from theoretical expectations.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2014-08-07T20:00:06.000Z",
      "title": "Dark matter searches going bananas: the contribution of Potassium (and Chlorine) to the 3.5 keV line",
      "abstract": "We examine the claimed excess X-ray line emission near 3.5 keV with a new analysis of XMM-Newton observations of the Milky Way center and with a re-analysis of the data on M31 and clusters. In no case do we find conclusive evidence for an excess. We show that known plasma lines, including in particular K XVIII lines at 3.48 and 3.52 keV, provide a satisfactory fit to the XMM data from the Galactic center. We assess the expected flux for the K XVIII lines and find that the measured line flux falls squarely within the predicted range based on the brightness of other well-measured lines in the energy range of interest. We then re-evaluate the evidence for excess emission from clusters of galaxies, including a previously unaccounted for Cl XVII line at 3.51 keV, and allowing for systematic uncertainty in the expected flux from known plasma lines and for additional uncertainty due to potential variation in the abundances of different elements. We find that no conclusive excess line emission is present within the systematic uncertainties in Perseus or in other clusters. Finally, we re-analyze XMM data for M31 and find no statistically significant line emission near 3.5 keV to a level greater than one sigma.",
      "comment": "9 pages, 3 tables, 3 figures; submitted to MNRAS",
      "journal": null,
      "doi": null
    },
    {
      "version": "v2",
      "updated": "2015-04-08T22:00:35.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galactic center",
      "kev line",
      "excess x-ray line emission",
      "astronomical targets",
      "critical look"
    ],
    "publication": {
      "doi": "10.1093/mnras/stv768",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2015,
      "month": "Jun",
      "volume": 450,
      "number": 2,
      "pages": 2143
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1310234,
      "adsabs": "2015MNRAS.450.2143J"
    }
  }
}