The MUSE Hubble Ultra Deep Field Survey

Abstract

We have conducted a two-layered spectroscopic survey (1 × 1 ultra deep and 3 × 3 deep regions) in the Hubble Ultra Deep Field (HUDF) with the Multi Unit Spectroscopic Explorer (MUSE). The combination of a large field of view, high sensitivity, and wide wavelength coverage provides an order of magnitude improvement in spectroscopically confirmed redshifts in the HUDF; i.e., 1206 secure spectroscopic redshifts for HST continuum selected objects, which corresponds to 15% of the total (7904). The redshift distribution extends well beyond z > 3 and to HST/F775W magnitudes as faint as ≈ 30 mag (AB, 1σ). In addition, 132 secure redshifts were obtained for sources with no Hubble Space Telescope (HST) counterparts that were discovered in the MUSE data cubes by a blind search for emission-line features. In total, we present 1338 high quality redshifts, which is a factor of eight increase compared with the previously known spectroscopic redshifts in the same field. We assessed redshifts mainly with the spectral features [O ii] at z < 1.5 (473 objects) and Lyα at 2.9 < z < 6.7 (692 objects). With respect to F775W magnitude, a 50% completeness is reached at 26.5 mag for ultra deep and 25.5 mag for deep fields, and the completeness remains 20% up to 28 − 29 mag and ≈ 27 mag, respectively. We used the determined redshifts to test continuum color selection (dropout) diagrams of high-z galaxies. The selection condition for F336W dropouts successfully captures ≈ 80% of the targeted z ∼ 2.7 galaxies. However, for higher redshift selections (F435W, F606W, and F775W dropouts), the success rates decrease to ≈ 20 − 40%. We empirically redefine the selection boundaries to make an attempt to improve them to ≈ 60%. The revised boundaries allow bluer colors that capture Lyα emitters with high Lyα equivalent widths falling in the broadbands used for the color-color selection. Along with this paper, we release the redshift and line flux catalog.

Simulating JWST/NIRCam Color Selection of High-redshift Galaxies

“…We find that the accuracy for dropout samples without Lyα emission is higher than samples with the emission line, with the highest significance for F115W dropouts. Similar results were seen for observations of galaxies in the Hubble Ultra Deep Field (HUDF) with the Multi Unit Spectroscopic Explorer (MUSE) in Inami et al (2017), where these authors present HST color cuts to select for Lyα emitters at 2.9 < z < 6.7.…”

The ALMA Spectroscopic Survey in the HUDF: A Model to Explain Observed 1.1 and 0.85 mm Dust Continuum Number Counts

“…These include constraints on the dust mass function, cosmic density of dust, but also the connection between stellar mass and SFR and dust properties. An approach to observationally probe the luminosity function would be to cross-correlate the securely detected dust continuum sources with information from spectroscopic surveys of the UDF for example with MUSE (Inami et al 2017;Boogaard et al 2019) or based on ALMA spectral information (González-López et al 2019).…”

Elevated ionizing photon production efficiency in faint high-equivalent-width Lyman-α emitters

“…Using data from the MUSE spectrograph (Bacon et al 2010) on the Very Large Telescope, we select high-EW LAEs from the MUSE UDF survey (Bacon et al 2017;Inami et al 2017). This survey covers approximately 9 square arcminutes to a depth of 10 to 30 hours at optical wavelengths (4750 − 9300Å).…”