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We present an analysis of |${\rm H\,\rm{\small {I}}}$| Lyman  |$\alpha$| emission in deep VLT/MUSE observations of two highly magnified and extended galaxies at |$z=3.5$| and 4.03, including a newly discovered, almost complete Einstein ring. While these Lyman  |$\alpha$| haloes are intrinsically similar to the ones typically seen in other MUSE deep fields, the benefits of gravitational lensing allow us to construct exceptionally detailed maps of Lyman  |$\alpha$| line properties at sub-kpc scales. By combining all multiple images, we are able to observe complex structures in the Lyman  |$\alpha$| emission and uncover small (⁠|$\sim120$| km s−1 in Lyman  |$\alpha$| peak shift), but significant at |$ \gt $| 4  |$\sigma$|⁠ , systematic variations in the shape of the Lyman  |$\alpha$| line profile within each halo. Indeed, we observe a global trend for the line peak shift to become redder at large radii, together with a strong correlation between the peak wavelength and line width. This systematic intrahalo variation is markedly similar to the object-to-object variations obtained from the integrated properties of recent large samples. Regions of high surface brightness correspond to relatively small line shifts, which could indicate that Lyman  |$\alpha$| emission escapes preferentially from regions where the line profile has been less severely affected by scattering of Lyman  |$\alpha$| photons. [ABSTRACT FROM AUTHOR]

The existence of a spatially resolved star-forming main sequence (rSFMS) and a spatially resolved mass–metallicity relation (rMZR) is now well established for local galaxies. Moreover, gradients with metallicity decreasing with radius seem to be common in local disc galaxies. These observations suggest that galaxy formation is a self-regulating process, and provide constraints for galaxy evolution models. Studying the evolution of these relations at higher redshifts is still, however, very challenging. In this paper, we analyse three gravitationally lensed galaxies at z  = 0.6, 0.7, and 1, observed with MUSE and SINFONI. These galaxies are highly magnified by galaxy clusters, which allow us to observe resolved scaling relations and metallicity gradients on physical scales of a couple of hundred parsecs, comparable to studies of local galaxies. We confirm that the rSFMS is already in place at these redshifts on sub-kpc scales, and establish, for the first time, the existence of the rMZR at higher redshifts. We develop a forward-modelling approach to fit 2D metallicity gradients of multiply imaged lensed galaxies in the image plane, and derive gradients of −0.027 ± 0.003, −0.019 ± 0.003, and −0.039 ± 0.060 dex kpc−1. Despite the fact that these are clumpy galaxies, typical of high-redshift discs, the metallicity variations in the galaxies are well described by global linear gradients, and we do not see any difference in metallicity associated with the star-forming clumps. [ABSTRACT FROM AUTHOR]

We analyse a sample of eight highly magnified galaxies at redshift 0.6 < z < 1.5 observed with MUSE, exploring the resolved properties of these galaxies at sub-kiloparsec scales. Combining multiband HST photometry and MUSE spectra, we derive the stellar mass, global star formation rates (SFRs), extinction and metallicity from multiple nebular lines, concluding that our sample is representative of z ~ 1 star-forming galaxies. We derive the 2D kinematics of these galaxies from the [OII ] emission and model it with a new method that accounts for lensing effects and fits multiple images simultaneously. We use these models to calculate the 2D beam-smearing correction and derive intrinsic velocity dispersion maps. We find them to be fairly homogeneous, with relatively constant velocity dispersions between 15 and 80 km s-1 and Gini coefficient of ≲0.3. We do not find any evidence for higher (or lower) velocity dispersions at the positions of bright star-forming clumps. We derive resolved maps of dust attenuation and attenuation-corrected SFRs from emission lines for two objects in the sample. We use this information to study the relation between resolved SFR and velocity dispersion. We find that these quantities are not correlated, and the high-velocity dispersions found for relatively low star-forming densities seems to indicate that, at sub-kiloparsec scales, turbulence in high-z discs is mainly dominated by gravitational instability rather than stellar feedback. [ABSTRACT FROM AUTHOR]

One of the key goals of the BLUEDISK survey is to characterize the impact of gas accretion in disc galaxies in the context of galaxy evolution. It contains 50 disc galaxies in the stellar mass range 1010-1011M☉, of which half are bluer and more HI-rich galaxies than their HInormal (control) counterparts. In this paper, we investigate how ongoing disc growth affects the molecular gas distribution and the star formation efficiency in these galaxies. We present 12CO observations from the IRAM 30-m telescope in 26 galaxies of the BLUEDISK survey. We compare the amount and spatial distribution of the molecular gas to key quantities such as atomic gas, stellar mass and surface density, star formation rate (SFR) and metallicity. We analyse the SFR per unit gas (SFR/H I and SFR/H2) and relate all those parameters to general galaxy properties (HI-rich/control disc, morphology, etc.). We find that the HI-rich galaxies have similar H2 masses as the control galaxies. In their centres, HI-rich galaxies have lower H2/H I ratios and marginally shorter molecular gas depletion times. However, the main differences between the two samples occur in the outer parts of the discs, with the HI-rich galaxies having slightly smaller CO discs (relative to the optical radius R25) and steeper CO and metallicity gradients than the control galaxies. The ongoing accretion of HI at large radii has thus not led to an appreciable growth of the CO discs in our sample. Based on depletion times, we estimate that this gas will contribute to star formation on time-scales of at least 5 Gyr. [ABSTRACT FROM AUTHOR]