MXDF: THE MUSE EXTREME DEEP FIELD IN THE HUBBLE UDF AREA

The MUSE Hubble Ultra-Deep Field survey 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. 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. 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).