{
  "id": "1810.01430",
  "version": "v1",
  "published": "2018-10-02T18:01:06.000Z",
  "updated": "2018-10-02T18:01:06.000Z",
  "title": "Tidal Interactions and Mergers in Intermediate Redshift EDisCS Clusters",
  "authors": [
    "Sinan Deger",
    "Gregory Rudnick",
    "Kshitija Kelkar",
    "Alfonso Aragón-Salamanca",
    "Vandana Desai",
    "Jennifer M. Lotz",
    "Pascale Jablonka",
    "John Moustakas",
    "Dennis Zaritsky"
  ],
  "comment": "16 figures, 4 tables. Accepted for publication in the Astrophysical Journal",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We study the fraction of tidal interactions and mergers with well identified observability timescales ($f_{\\rm TIM}$) in group, cluster, and accompanying field galaxies and its dependence on redshift ($z$), cluster velocity dispersion ($\\sigma$) and environment analyzing HST-ACS images and catalogs from the ESO Distant Cluster Survey (EDisCS). Our sample consists of 11 clusters, 7 groups, and accompanying field galaxies at $0.4 \\leq z \\leq 0.8$. We derive $f_{\\rm TIM}$ using both a visual classification of galaxy morphologies and an automated method, the $G-M_{20}$ method. We calibrate this method using the visual classifications that were performed on a subset of our sample. We find marginal evidence for a trend between $f_{\\rm TIM}$ and $z$, in that higher $z$ values correspond to higher $f_{\\rm TIM}$. However, we also cannot rule out the null hypothesis of no correlation at higher than 68% confidence. No trend is present between $f_{\\rm TIM}$ and $\\sigma$. We find that $f_{\\rm TIM}$ shows suggestive peaks in groups, and tentatively in clusters at $R > 0.5\\times R_{200}$, implying that $f_{\\rm TIM}$ gets boosted in these intermediate density environments. However, our analysis of the local densities of our cluster sample does not reveal a trend between $f_{\\rm TIM}$ and density, except for a potential enhancement at the very highest densities. We also perform an analysis of projected radius-velocity phase space for our cluster members. Our results reveal that tidal interactions and mergers (TIM), and undisturbed galaxies only have a 6% probability of having been drawn from the same parent population in their velocity distribution and 37% in radii, in agreement with the modest differences obtained in $f_{\\rm TIM}$ at the clusters.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-10-02T18:01:06.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "intermediate redshift ediscs clusters",
      "tidal interactions",
      "accompanying field galaxies",
      "visual classification",
      "eso distant cluster survey"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}