In this Letter, we revisit the relationship between the fraction of the intra-cluster light (ICL) as well as the virial mass and the fraction of early-type galaxies in the host halo. This exploration is based on a statistically significant and homogeneous sample of 22 groups and clusters of galaxies in the Local Universe (z ≤ 0.05), obtained with the VST Early-type GAlaxy Survey (VEGAS). Taking advantage of the long integration time and large area of the VEGAS images, we are able to map the galaxy outskirts and ICL down to μg ≥ 29–30 mag arcsec−2 and out to hundreds of kpc. With this data set, we have expanded the sample of ICL measurements, doubling the previous measures available from the literature for z ≤ 0.05. The main result of this work is the apparent lack of any significant trend between the fraction of ICL and the virial mass of the host environment, covering a wide range of virial masses (∼1012.5 ≤ Mvir ≤ 1015.5 M⊙), in full agreement with a number of theoretical studies. Since the new data points have all been derived based on the same methodology and from the same observational setup, all with comparable depths, the large observed scatter indicates an intrinsic variation in the ICL fraction. On the other hand, there is a weak relationship between the fraction of ICL and the fraction of early-type galaxies in the host halo, where a larger fraction of ICL is found in groups and clusters of galaxies dominated by earlier morphological types, indicating a connection between the ICL and the dynamical state of the host system.

In this paper we present the deep, wide-field and multi-band imaging of the LEO I pair NGC 3379-NGC 3384, from the VST Early-type GAlaxy Survey (VEGAS). The main goal of this study is to map the intra-group baryons in the pair, in the form of diffuse light and globular clusters (GCs). Taking advantage from the large covered area, which extends for ∼ 3.9 square degrees around the pair, and the long integration time, we can map the light distribution out to ∼ 63 kpc and down to ∼ 30 mag/arcsec2 in the g band and ∼ 29 mag/arcsec2 in the r band, deeper than previous data available for this target. The map of the intra-group light (IGL) presents two very faint (μg ∼ 28-29 mag/arcsec2) streams protruding from the brightest group member NGC 3379 and elongated toward North-West and South. We estimate that the fraction of the stellar halo around NGC 3379 plus the intra-group light is ∼17±2% in both g and r bands, with an average color g-r = 0.75 ± 0.04 mag. The color distribution of the GCs appears multi-modal, with two dominant peaks at (u-r) = 1.8 mag and (u-r) = 2.1 mag, respectively. The GC population stretches from North-East to South-West and from North-West to South of the pair, in the last case overlapping with the streams of IGL, as well as the PNe distribution found by Hartke et al. (Hartke et al., A&A, 2020, 642, A46) and Hartke et al. (Hartke et al., 2022). Since these structures are elongated in the direction of the two nearby galaxies M96 and NGC 3338, they could be the remnant of a past gravitational interactions with the pair.

In this work we extend the catalog of low-surface brightness (LSB) galaxies, including Ultra-Diffuse Galaxy (UDG) candidates, within ≈ 0.4R vir of the Hydra I cluster of galaxies, based on deep images from the VST Early-type GAlaxy Survey (VEGAS). The new galaxies are found by applying an automatic detection tool and carrying out additional visual inspections of g and r band images. This led to the detection of 11 UDGs and 8 more LSB galaxies. For all of them, the cluster membership has been assessed using the color-magnitude relation derived for early-type giant and dwarf galaxies in Hydra I. The UDGs and new LSB galaxies found in Hydra I span a wide range of central surface brightness (22.7 µ 0,g 26.5 mag/arcsec 2 ), effective radius (0.6 R e 4.0 kpc) and color (0.4 ≤ g − r ≤ 0.9 mag), and have stellar masses in the range ∼ 5 × 10 6 − 2 × 10 8 M . The 2D projected distribution of both galaxy types is similar to the spatial distribution of dwarf galaxies, with over-densities in the cluster core and north of the cluster centre. They have similar color distribution and comparable stellar masses to the red dwarf galaxies. Based on photometric selection, we identify a total of 9 globular cluster candidates associated to the UDGs and 4 to the LSB galaxies, with the highest number of candidates in an individual UDG being three. We find that there are no relevant differences between dwarfs, LSB galaxies and UDGs: the structural parameters (that is surface brightness, size, colors, n-index) and GCs content of the three classes have similar properties and trends. This finding is consistent with UDGs being the extreme LSB tail of the size-luminosity distribution of dwarfs in this environment.