---
res:
  bibo_abstract:
  - The H i gas distribution in damped Lyman $\alpha$ absorbers (DLAs) has remained
    elusive due to the point-source nature of background quasar emission. Observing
    DLAs against spatially extended background galaxies provides a new method for
    constraining their size and structure. Using the Keck Cosmic Web Imager, we present
    the first ‘silhouette’ image of a DLA at $z=3.34$, identified in the spectrum
    of a background galaxy at $z=3.61$. Although the silhouette remains unresolved
    due to limited spatial resolution, this represents a successful proof-of-concept
    for studying DLA morphology using extended background sources. Possible residual
    emission in the DLA trough suggests an optical depth contrast exceeding $10^7$
    in the internal structure, implying a sharp edge or patchy structure. A Lyman $\alpha$
    emitter (LAE) at $z_{\rm LAE}=3.3433\pm 0.0005$, consistent with the DLA redshift,
    is detected at an angular separation of $1{{_{.}^{\prime\prime}} }73\pm 0{{_{.}^{\prime\prime}}
    }28$ ($12.9\pm 2.1$ kpc). The DLA is surrounded by three galaxies within 140 kpc
    in projected distance and 500 km s$^{-1}$ in line-of-sight velocity, indicating
    that it resides in the circumgalactic medium of the LAE or within a galaxy group/protocluster
    environment. An O i  $\lambda 1302$ absorption at $z_{\rm OI}=3.3288\pm 0.0004$
    is also detected along the line of sight. This absorber may trace metal-enriched
    outflow from the LAE or a gas-rich galaxy exhibiting the highest star formation
    activity among the surrounding galaxies. Future large spectroscopic surveys of
    galaxies will expand such a DLA sample, and three-dimensional spectroscopy for
    it will shed new light on the role of intergalactic dense gas in galaxy formation
    and evolution.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Fuga
      foaf_name: Komori, Fuga
      foaf_surname: Komori
  - foaf_Person:
      foaf_givenName: Akio K
      foaf_name: Inoue, Akio K
      foaf_surname: Inoue
  - foaf_Person:
      foaf_givenName: Ken
      foaf_name: Mawatari, Ken
      foaf_surname: Mawatari
  - foaf_Person:
      foaf_givenName: Yuma
      foaf_name: Sugahara, Yuma
      foaf_surname: Sugahara
  - foaf_Person:
      foaf_givenName: Hideki
      foaf_name: Umehata, Hideki
      foaf_surname: Umehata
  - foaf_Person:
      foaf_givenName: Rhythm
      foaf_name: Shimakawa, Rhythm
      foaf_surname: Shimakawa
  - foaf_Person:
      foaf_givenName: Satoshi
      foaf_name: Yamanaka, Satoshi
      foaf_surname: Yamanaka
  - foaf_Person:
      foaf_givenName: Takuya
      foaf_name: Hashimoto, Takuya
      foaf_surname: Hashimoto
  - foaf_Person:
      foaf_givenName: Jorryt J
      foaf_name: Matthee, Jorryt J
      foaf_surname: Matthee
      foaf_workInfoHomepage: http://www.librecat.org/personId=7439a258-f3c0-11ec-9501-9df22fe06720
    orcid: 0000-0003-2871-127X
  - foaf_Person:
      foaf_givenName: Toru
      foaf_name: Misawa, Toru
      foaf_surname: Misawa
  bibo_doi: 10.1093/mnras/staf1622
  bibo_issue: '3'
  bibo_volume: 543
  dct_date: 2025^xs_gYear
  dct_identifier:
  - UT:001592326700001
  dct_isPartOf:
  - http://id.crossref.org/issn/0035-8711
  - http://id.crossref.org/issn/1365-2966
  dct_language: eng
  dct_publisher: Oxford University Press@
  dct_title: The first direct imaging of the silhouette of a damped Lyman α system
    along the line-of-sight to a background galaxy@
...