{
  "id": "2402.05788",
  "version": "v1",
  "published": "2024-02-08T16:25:20.000Z",
  "updated": "2024-02-08T16:25:20.000Z",
  "title": "The roles of environment and interactions on the evolution of red and blue galaxies in the EAGLE simulation",
  "authors": [
    "Apashanka Das",
    "Biswajit Pandey"
  ],
  "comment": "19 pages, 10 figures, comments welcome",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "We study the evolution of the red and blue galaxies from $z=3$ to $z=0$ using the EAGLE simulation. The galaxies in the blue cloud and the red sequence are separated at each redshift using a scheme based on Otsu's method. Our analysis shows that the two populations have small differences in the local density and the clustering strength until $z=2$, after which the red galaxies preferentially occupy the denser regions and exhibit a significantly stronger clustering than the blue galaxies. The large differences in the cold gas mass and the star formation rate (SFR) of the two populations before $z=2$ indicate that the dichotomy between the two populations may not arise due to the environment alone. The galaxy pairs at each redshift show a significantly higher SFR than the isolated control galaxies within pair separations $<200$ kpc. The SFR of the paired galaxies at a given separation declines with the decreasing redshift, indicating a gradual depletion of their cold gas reservoir. At smaller pair separations, an anomalous increase of the SFR in paired galaxies around $z \\sim 2$, suggests that the environmental effects start to dominate at this redshift, increasing the rate of galaxy interactions and the occurrence of starburst galaxies. We observe a substantial decrease in the blue fraction in paired galaxies starting from $z=1$ to the present. The decrease in the blue fraction is mild for the paired galaxies with their second nearest neighbour at a distance $>500$ kpc.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-02-08T16:25:20.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "blue galaxies",
      "eagle simulation",
      "paired galaxies",
      "interactions",
      "blue fraction"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 19,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}