The MUSEHubbleUltra Deep Field surveys: Data release II

Abstract

We present the second data release of the MUSE Hubble Ultra-Deep Field surveys, which includes the deepest spectroscopic survey ever performed. The MUSE data, with their 3D content, amazing depth, wide spectral range, and excellent spatial and medium spectral resolution, are rich in information. Their location in the Hubble ultra-deep field area, which benefits from an exquisite collection of ancillary panchromatic information, is a major asset. This update of the first release incorporates a new 141-hour adaptive-optics-assisted MUSE eXtremely Deep Field (MXDF; 1 arcmin diameter field of view) in addition to the reprocessed 10-hour mosaic (3 × 3 arcmin 2 ) and the single 31-hour deep field (1 × 1 arcmin 2 ). All three data sets were processed and analyzed homogeneously using advanced data reduction and analysis methods. The 3σ point-source flux limit of an unresolved emission line reaches 3.1×10 −19 and 6.3×10 −20 erg s −1 cm −2 at 10-and 141-hour depths, respectively. We have securely identified and measured the redshift of 2221 sources, an increase of 41% compared to the first release. With the exception of eight stars, the collected sample consists of 25 nearby galaxies (z < 0.25), 677 [O ii] emitters (z = 0.25 − 1.5), 201 galaxies in the MUSE redshift desert range (z = 1.5 − 2.8), and 1308 Lyα emitters (z = 2.8 − 6.7). This represents an order of magnitude more redshifts than the collection of all spectroscopic redshifts obtained before MUSE in the Hubble ultra-deep field area (i.e., 2221 versus 292). At high redshift (z > 3), the difference is even more striking, with a factor of 65 increase (1308 versus 20). We compared the measured redshifts against three published photometric redshift catalogs and find the photo-z accuracy to be lower than the constraints provided by photo-z fitting codes. Eighty percent of the galaxies in our final catalog have an HST counterpart. These galaxies are on average faint, with a median AB F775W magnitude of 25.7 and 28.7 for the [O ii] and Lyα emitters, respectively. Fits of their spectral energy distribution show that these galaxies tend to be low-mass star-forming galaxies, with a median stellar mass of 6.2 × 10 8 M and a median star-formation rate of 0.4 M yr −1 . We measured the completeness of our catalog with respect to HST and found that, in the deepest 141-hour area, 50% completeness is achieved for an AB magnitude of 27.6 and 28.7 (F775W) at z = 0.8 − 1.6 and z = 3.2 − 4.5, respectively. Twenty percent of our catalog, or 424 galaxies, have no HST counterpart. The vast majority of these new sources are high equivalent-width z > 2.8 Lyα emitters that are detected by MUSE thanks to their bright and asymmetric broad Lyα line. We release advanced data products, specific software, and a web interface to select and download data sets.

The MUSE Ultra Deep Field (MUDF). III. Hubble Space Telescope WFC3 Grism Spectroscopy and Imaging

“…However, studying the connections between low-mass galaxies and the CGM at high redshift is challenging because the gas structures are intrinsically faint. In addition, the multiphase nature of the gas can only be fully characterized by combining the results of sensitive emission and absorption line studies (e.g., Steidel et al 2010;Crighton et al 2011;Turner et al 2014;Bielby et al 2019;Lofthouse et al 2020;Stott et al 2020;Beckett et al 2021;Cooper et al 2021;Fossati et al 2021;Zabl et al 2021;Bacon et al 2023).…”

Clustering dependence on Lyα luminosity from MUSE surveys at 3 < z < 6

“…Contained in the last observed region, an even deeper survey (140 h) is then built up (at the top of the cake). These three surveys are known as: MUSE-Wide (Herenz et al 2017;Urrutia et al 2019), MUSE-Deep (Bacon et al 2017(Bacon et al , 2023Inami et al 2017), and MUSE Extremely Deep Field (MXDF; Bacon et al 2023). Each of them can be seen as a different layer of a wedding cake, where higher layers become spatially smaller and correspond to deeper observations.…”

“…The main properties of the MUSE-Wide LAEs are summarized in Table 1. -Deep (10 h MOSAIC;Bacon et al 2017Bacon et al , 2023Inami et al 2017) encompasses nine fields located in the CANDELS/GOODS-S region of the HUDF, each spanning 1 arcmin 2 and observed with a 10 h exposure time. The total A5, page 2 of 17 spatial coverage is 9.92 arcmin 2 .…”

“…We did, however, remove the MUSE-Deep objects that are selected in the deepest survey, described in the next section. We refer to Bacon et al (2017Bacon et al ( , 2023 for a detailed description on survey construction and data reduction.…”

“…The MUSE Extremely Deep Field (Bacon et al 2023) is situated in the CANDELS/GOODS-S region and overlaps with MUSE-Deep and MUSE-Wide. It is composed of a single quasi circular field with inner and outer radii of 31 and 41 , respectively.…”