The MUSE 3D view of theHubbleDeep Field South

Abstract

We observed Hubble Deep Field South with the new panoramic integral-field spectrograph MUSE that we built and have just commissioned at the VLT. The data cube resulting from 27 h of integration covers one arcmin 2 field of view at an unprecedented depth with a 1σ emission-line surface brightness limit of 1 × 10 −19 erg s −1 cm −2 arcsec −2 , and contains ∼90 000 spectra. We present the combined and calibrated data cube, and we performed a first-pass analysis of the sources detected in the Hubble Deep Field South imaging. We measured the redshifts of 189 sources up to a magnitude I 814 = 29.5, increasing the number of known spectroscopic redshifts in this field by more than an order of magnitude. We also discovered 26 Lyα emitting galaxies that are not detected in the HST WFPC2 deep broad-band images. The intermediate spectral resolution of 2.3 Å allows us to separate resolved asymmetric Lyα emitters, [O ]3727 emitters, and C ]1908 emitters, and the broad instantaneous wavelength range of 4500 Å helps to identify single emission lines, such as [O ]5007, Hβ, and Hα, over a very wide redshift range. We also show how the three-dimensional information of MUSE helps to resolve sources that are confused at ground-based image quality. Overall, secure identifications are provided for 83% of the 227 emission line sources detected in the MUSE data cube and for 32% of the 586 sources identified in the HST catalogue. The overall redshift distribution is fairly flat to z = 6.3, with a reduction between z = 1.5 to 2.9, in the well-known redshift desert. The field of view of MUSE also allowed us to detect 17 groups within the field. We checked that the number counts of [O ]3727 and Lyα emitters are roughly consistent with predictions from the literature. Using two examples, we demonstrate that MUSE is able to provide exquisite spatially resolved spectroscopic information on the intermediate-redshift galaxies present in the field. This unique data set can be used for a wide range of follow-up studies. We release the data cube, the associated products, and the source catalogue with redshifts, spectra, and emission-line fluxes.

The MUSE Hubble Ultra Deep Field Survey

“…Another MUSE deep survey in the Hubble Deep Field South (HDFS; Bacon et al 2015), whose coverage is also a single MUSE field of view as our udf-10 and has a similar depth (27 hours), reaches the 50% completeness at 26 mag in the HST F814W band. The achieved slightly higher completeness in udf-10 is a natural consequence of the better line flux detection limit, which results from the improved data reduction and analysis compared to the HDFS data cubes (Bacon et al 2015).…”

“…The achieved slightly higher completeness in udf-10 is a natural consequence of the better line flux detection limit, which results from the improved data reduction and analysis compared to the HDFS data cubes (Bacon et al 2015).…”

“…This process can exclude faint galaxies, including quiescent absorption line galaxies it can deal with dense fields without making any target preselection, achieving a spatially homogeneous spectroscopic completeness and reducing the uncertainty in assigning a measured redshift to a photometric object (cf. Bacon et al 2015;Brinchmann et al 2017).…”

“…The three-dimensional data of MUSE also facilitate blind identifications of previously unknown sources by searching for emission lines directly in the data cube (cf. Bacon et al 2015). In addition to increasing the spectroscopic completeness in the HUDF with MUSE, the unique capabilities of MUSE have permitted some of the first detailed investigations of photo-z calibration of faint objects up to 30th magnitude , hereafter Paper III), properties of a statistical sample of C iii] emitters (Maseda et al 2017), spatially resolved stellar kinematics of intermediate redshift galaxies (Guérou et al 2017), constraints on the faint-end slope of Lyman-α (Lyα) luminosity functions and its evolution (Drake et al 2017), spatial extents of a large number of Lyα haloes (Leclercq et al 2017), redshift dependence of the Lyα equivalent width and the UV continuum slope , galactic winds in star-forming galaxies (Finley et al 2017), evolution of the galaxy merger rate (Ventou et al 2017), and analyses of the cosmic web (Gallego et al 2017).…”

UBIQUITOUS GIANT Lyα NEBULAE AROUND THE BRIGHTEST QUASARS AT z ∼ 3.5 REVEALED WITH MUSE∗

“…It is known that MUSE cubes reduced with the standard pipeline might have small astrometric offsets in the coordinate system because of a small "derotator wobble" (Bacon et al 2015). To correct for this effect, we registered the datacubes using the position of point sources in MUSE whitelight images (obtained by collapsing the datacubes along the wavelength direction) in different exposures.…”