The MUSEHubbleUltra Deep Field Survey

Abstract

Non-resonant Fe ii* (λ2365, λ2396, λ2612, λ2626) emission can potentially trace galactic winds in emission and provide useful constraints to wind models. From the 3.15 × 3.15 mosaic of the Hubble Ultra Deep Field (UDF) obtained with the VLT/MUSE integral field spectrograph, we identify a statistical sample of 40 Fe ii* emitters and 50 Mg ii (λλ2796, 2803) emitters from a sample of 271 [O ii]λλ3726, 3729 emitters with reliable redshifts from z = 0.85 − 1.50 down to 2 × 10 −18 (3 σ) ergs s, covering the M range from 10 8 − 10 11 M . The Fe ii* and Mg ii emitters follow the galaxy main sequence, but with a clear dichotomy. Galaxies with masses below 10 9 M and star formation rates (SFRs) of 1 M yr −1 have Mg ii emission without accompanying Fe ii* emission, whereas galaxies with masses above 10 10 M and SFRs 10 M yr −1 have Fe ii* emission without accompanying Mg ii emission. Between these two regimes, galaxies have both Mg ii and Fe ii* emission, typically with Mg ii P-Cygni profiles. Indeed, the Mg ii profile shows a progression along the main sequence from pure emission to P-Cygni profiles to strong absorption, due to resonant trapping. Combining the deep MUSE data with HST ancillary information, we find that galaxies with pure Mg ii emission profiles have lower star formation rate surface densities than those with either Mg ii P-Cygni profiles or Fe ii* emission. These spectral signatures produced through continuum scattering and fluorescence, Mg ii P-Cygni profiles and Fe ii* emission, are better candidates for tracing galactic outflows than pure Mg ii emission, which may originate from H ii regions. We compare the absorption and emission rest-frame equivalent widths for pairs of Fe ii transitions to predictions from outflow models and find that the observations consistently have less total re-emission than absorption, suggesting either dust extinction or non-isotropic outflow geometries.

Probing 3D Structure with a Large MUSE Mosaic: Extending the Mass Model of Frontier Field Abell 370

“…We also identify a strong C iii] emitter in the southwest of the cluster (ID 4139; z = 1.9655) with a bright UV continuum and several other emission and absorption features, including Fe ii * [λ ∼ 2400,λ ∼ 2600] emission, which is useful for probing galactic winds (see e.g. Finley et al 2017). Additionally, we identify a fourth potential C iii] emitter (ID 11481; z = 2.5607) in the northeast, and three objects with weak UV absorption features (ID 6655; z = 2.1240, ID 13600; z = 2.5442, and ID 14822; z = 2.8897) at the western edges of the mosaic, but we stress that these identifications are made at low confidence (C = 1) and could simply be noise.…”

Mg II λ2797, λ2803 emission in a large sample of low-metallicity star-forming galaxies from SDSS DR14

“…The same is also shown in b), but galaxies with redshift z < 0.3 are excluded from the entire SDSS DR14 sample. Mg II and Fe II * emitters from the Ultra Deep Field, UDF-10, by Finley et al (2017) are shown by large symbols. In particular, Mg II emitting galaxies are denoted by large blue filled circles (where SFR values are obtained from SED fitting) and by open circles (where SFR values are obtained from the luminosity of [O II] lines).…”

The MUSE Hubble Ultra Deep Field Survey

“…The faint end of the Lyα luminosity function and its implication for reionization are presented in Paper VI (Drake et al 2017b). The properties of Fe ii* emission, as tracer of galactic winds in star-forming galaxies is presented in Paper VII (Finley et al 2017b). Extended Lyα haloes around individual Lyα emitters are discussed in Paper VIII (Leclercq et al 2017).…”