Using MUSE AO data, we probe the ISM in the local spiral galaxy NGC 7793 at aspatial resolution of $\sim$ 10 pc. We identify HII regions and compile acatalogue of supernova remnants (SNRs), planetary nebulae (PNe) and Wolf Rayetstars (WR). We compute electron densities and temperatures from the[SII]6716/6731 and [SIII]6312/9069 line ratios. We study the properties of theionised gas through BPT diagrams combined with gas velocity dispersion. Wespectroscopically confirm 2 previously detected WR stars and a SNR and reportthe discovery of 7 WR, 1 SNR, and 2 PNe. The diffuse ionized gas (DIG) fractionis between $\sim$ 27 and 42% depending on the method used to define the HIIregion boundaries. In agreement with previous studies, we find that the DIGexhibits enhanced [SII]/H$\alpha$ and [NII]/H$\alpha$ ratios and a mediantemperature that is $\sim$ 3000 K higher than in HII regions. We also observean apparent inverse correlation between temperature and H$\alpha$ surfacebrightness. Overall, the observed [SII]6716/6731 ratio is consistent within1$\sigma$ with $n_e$ < 30 cm$^{-3}$, with an almost identical distribution forthe DIG and HII regions. The velocity dispersion of the ionised gas indicatesthat the DIG has a higher degree of turbulence than the HII regions. Comparisonwith photoionisation and shock models reveals that the diffuse component canonly partially be explained via shocks and that it is most likely consistentwith photons leaking from density bounded HII regions or with radiation fromevolved field stars. [abridged]

Galactic outflows driven by stellar feedback are crucial for explaining theinefficiency of galaxy formation. Although strong feedback can promote theformation of galactic discs by limiting star formation at early times andremoving low angular momentum gas, it is not understood how the same feedbackcan result in diverse objects such as elliptical galaxies or razor thin spiralgalaxies. In this work, we investigate this problem using cosmological zoom-insimulations of two galaxies forming within $10^{12}~\mathrm{M_\odot}$ haloswith almost identical mass accretion histories. At $z>1.5$, the two galaxiesfeature a surface density of star formation $\Sigma_{\rm SFR}\simeq10~\mathrm{M_\odot}~{\rm yr}^{-1}~{\rm kpc}^{-2}$, leading to strong outflows.After the last starburst episode, both galaxies feature a dramatic gaseous discgrowth from 1 kpc to 5 kpc during 1 Gyr, a decisive epoch we dub "the GrandTwirl". After this episode, the evolutionary tracks diverge, with one galaxyending up as a bulge-dominated galaxy, whereas the other ends up as adisc-dominated galaxy. The origins of this dichotomy are the angular momentumof the accreted gas, and whether it adds constructively to the initial discangular momentum. The build-up of this extended disc leads to a rapid loweringof $\Sigma_{\rm SFR}$ by over two orders of magnitude with $\Sigma_{\rm SFR}\lesssim 0.1~\mathrm{M_\odot}~{\rm yr}^{-1}~{\rm kpc}^{-2}$, in remarkableagreement with what is derived from Milky Way stellar populations in the solarneighbourhood. As a consequence, supernovae explosions are spread out andcannot launch galactic outflows anymore, allowing for the persistence of athin, gently star forming, extended disc.

We show that a combined analysis of CMB anisotropy power spectra obtained bythe Planck satellite and luminosity distance data simultaneously excludes aflat universe and a cosmological constant at $99 \%$ C.L. These results holdseparately when combining Planck with three different datasets: the twodeterminations of the Hubble constant from Riess et al. 2019 and Freedman etal. 2020, and the Pantheon catalog of high redshift supernovae type-Ia. Weconclude that either LCDM needs to be replaced by a drastically differentmodel, or else there are significant but still undetected systematics. Ourresult calls for new observations and stimulates the investigation ofalternative theoretical models and solutions.