{
  "id": "1705.00653",
  "version": "v1",
  "published": "2017-05-01T18:27:35.000Z",
  "updated": "2017-05-01T18:27:35.000Z",
  "title": "Herschel Spectroscopy of Early Type Galaxies",
  "authors": [
    "Ryen Carl Lapham",
    "Lisa M. Young",
    "Alison Crocker"
  ],
  "comment": "This paper has been accepted to ApJ. The paper should be 24 pages and contains 16 figures",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We present Herschel spectroscopy of atomic lines arising in photodissociation regions as well as ionization regions of nearby early-type galaxies (ETGs), focusing on the volume-limited Atlas3D sample. Our data include the [CII], [OI], and [NII] 122 and 205 micron lines, along with ancillary data including CO and HI maps. We find ETGs have [CII]/FIR ratios slightly lower than spiral galaxies in the KINGFISH sample, and several ETGs have unusually large [NII] 122/[CII] ratios. The [NII] 122/[CII] ratio is correlated with UV colors and there is a strong anti-correlation of [CII]/FIR with NUV-K seen in both spirals and ETGs, likely due to a softer radiation field with fewer photons available to ionize carbon and heat the gas. The correlation thus makes a [CII] deficit in galaxies with redder stellar populations. The high [NII] 122/[CII] (and low [CII]/FIR) line ratios could also be affected by the removal of much of the diffuse, low density gas, which is consistent with the low HI/H2 ratios. [CII] is now being used as a star formation indicator, and we find it is just as good for ETGs as in spirals. The [CII]/CO ratios found are also similar to those found in spiral galaxies. Through use of the [NII] 205 micron line, estimates of the percentage of [CII] emission arising from ionized gas indicate a significant portion could arise in ionized regions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-05-01T18:27:35.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "early type galaxies",
      "herschel spectroscopy",
      "spiral galaxies",
      "micron line",
      "nearby early-type galaxies"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 24,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}