Linking gas and galaxies at high redshift: MUSE surveys the environments of six damped Lyα systems at z ≈ 3. Issue 4 (4th June 2019)

• Record Type: Journal Article
• Authors: Mackenzie, Ruari; Fumagalli, Michele; Theuns, Tom; Hatton, David J; Garel, Thibault; Cantalupo, Sebastiano; Christensen, Lise; Fynbo, Johan P U; Kanekar, Nissim; Møller, Palle; O'Meara, John; Prochaska, J Xavier; Rafelski, Marc; Shanks, Tom; Trayford, James
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 487:Issue 4(2019)
• Page Start: 5070
• Page End: 5096
• Publication Date: 2019-06-04
• Subjects: galaxies: evolution -- galaxies: formation -- intergalactic medium -- galaxies: high-redshift -- quasars: absorption lines; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz1501
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present results from a survey of galaxies in the fields of six z ≥ 3 damped Lyman α (Lyα) systems (DLAs) using the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). We report a high detection rate of up to ${\approx } 80{{\ \rm per\ cent}}$ of galaxies within 1000 km s −1 from DLAs and with impact parameters between 25 and 280 kpc. In particular, we discovered five high-confidence Lyα emitters associated with three DLAs, plus up to nine additional detections across five of the six fields. The majority of the detections are at relatively large impact parameters (>50 kpc) with two detections being plausible host galaxies. Among our detections, we report four galaxies associated with the most metal-poor DLA in our sample ( Z / Z ⊙ = −2.33 ± 0.22), which trace an overdense structure resembling a filament. By comparing our detections with predictions from the Evolution and Assembly of GaLaxies and their Environments (EAGLE) cosmological simulations and a semi-analytic model designed to reproduce the observed bias of DLAs at z > 2, we conclude that our observations are consistent with a scenario in which a significant fraction of DLAs trace the neutral regions within haloes with a characteristic mass of $M_{\rm h} \approx 10^{11}-10^{12}~\rm M_\odot$, in agreement with the inference made from the large-scale clustering of DLAs. We finally show how larger surveys targeting ≈25 absorbers have the potential of constraining the characteristic masses of haloes hosting high-redshift DLAs with sufficient accuracy to discriminate between different models.