@article{JohnsonChenStrakaetal.2018,
  author    = {Johnson, Sean D. and Chen, Hsiao-Wen and Straka, Lorrie and Schaye, Joop and Cantalupo, Sebastiano and Wendt, Martin and Muzahid, Sowgat and Bouch{\´e}, Nicolas and Herenz, Edmund Christian and Kollatschny, Wolfram and Mulchaey, John S. and Marino, Raffaella A. and Maseda, Michael and Wisotzki, Lutz},
  title     = {Galaxy and quasar fueling caught in the act from the intragroup to the interstellar medium},
  series = {The astrophysical journal : Part 2, Letters},
  volume    = {869},
  journal   = {The astrophysical journal : Part 2, Letters},
  number    = {1},
  publisher = {IOP Publishing Ltd. (Bristol)},
  address   = {Bristol},
  issn      = {2041-8205},
  doi       = {10.3847/2041-8213/aaf1cf},
  pages     = {7},
  year      = {2018},
  abstract  = {We report the discovery of six spatially extended (10-100 kpc) line-emitting nebulae in the z approximate to 0.57 galaxy group hosting PKS 0405-123, one of the most luminous quasars at z < 1. The discovery is enabled by the Multi Unit Spectroscopic Explorer and provides tantalizing evidence connecting large-scale gas streams with nuclear activity on scales of <10 proper kpc (pkpc). One of the nebulae exhibits a narrow, filamentary morphology extending over 50 pkpc toward the quasar with narrow internal velocity dispersion (50 km s(-1)) and is not associated with any detected galaxies, consistent with a cool intragroup medium filament. Two of the nebulae are 10 pkpc north and south of the quasar with tidal-arm-like morphologies. These two nebulae, along with a continuum-emitting arm extending 60 pkpc from the quasar, are signatures of interactions that are expected to redistribute angular momentum in the host interstellar medium (ISM) to facilitate star formation and quasar fueling in the nucleus. The three remaining nebulae are among the largest and most luminous [O III] emitting "blobs" known (1400-2400 pkpc(2)) and correspond both kinematically and morphologically to interacting galaxy pairs in the quasar host group, consistent with arising from stripped ISM rather than large-scale quasar outflows. The presence of these large- and small-scale nebulae in the vicinity of a luminous quasar bears significantly on the effect of large-scale environment on galaxy and black hole fueling, providing a natural explanation for the previously known correlation between quasar luminosity and cool circumgalactic medium.},
  language  = {en}
}
@article{WeilbacherMonrealIberoVerhammeetal.2018,
  author    = {Weilbacher, Peter Michael and Monreal-Ibero, Ana and Verhamme, Anne and Sandin, Christer and Steinmetz, Matthias and Kollatschny, Wolfram and Krajnovic, Davor and Kamann, Sebastian and Roth, Martin M. and Erroz-Ferrer, Santiago and Marino, Raffaella Anna and Maseda, Michael V. and Wendt, Martin and Bacon, Roland and Dreizler, Stefan and Richard, Johan and Wisotzki, Lutz},
  title     = {Lyman-continuum leakage as dominant source of diffuse ionized gas in the Antennae galaxy},
  series = {Astronomy and astrophysics : an international weekly journal},
  volume    = {611},
  journal   = {Astronomy and astrophysics : an international weekly journal},
  publisher = {EDP Sciences},
  address   = {Les Ulis},
  issn      = {1432-0746},
  doi       = {10.1051/0004-6361/201731669},
  pages     = {17},
  year      = {2018},
  abstract  = {The Antennae galaxy (NGC 4038/39) is the closest major interacting galaxy system and is therefore often studied as a merger prototype. We present the first comprehensive integral field spectroscopic dataset of this system, observed with the MUSE instrument at the ESO VLT. We cover the two regions in this system which exhibit recent star formation: the central galaxy interaction and a region near the tip of the southern tidal tail. In these fields, we detect H II regions and diffuse ionized gas to unprecedented depth. About 15\% of the ionized gas was undetected by previous observing campaigns. This newly detected faint ionized gas is visible everywhere around the central merger, and shows filamentary structure. We estimate diffuse gas fractions of about 60\% in the central field and 10\% in the southern region. We are able to show that the southern region contains a significantly different population of H II regions, showing fainter luminosities. By comparing H II region luminosities with the HST catalog of young star clusters in the central field, we estimate that there is enough Lyman-continuum leakage in the merger to explain the amount of diffuse ionized gas that we detect. We compare the Lyman-continuum escape fraction of each H II region against emission line ratios that are sensitive to the ionization parameter. While we find no systematic trend between these properties, the most extreme line ratios seem to be strong indicators of density bounded ionization. Extrapolating the Lyman-continuum escape fractions to the southern region, we conclude that simply from the comparison of the young stellar populations to the ionized gas there is no need to invoke other ionization mechanisms than Lyman-continuum leaking H II regions for the diffuse ionized gas in the Antennae.},
  language  = {en}
}