Nearby massive compact elliptical galaxies (MCEGs) are strong candidates forrelic galaxies (i.e. local analogs of red nuggets at high redshifts). It isexpected that the globular cluster (GC) systems of relic galaxies are dominatedby red (metal-rich) GCs. NGC 1277 is known as a unique example of such a galaxyin the previous study. In this study, we search for GCs in 12 nearby MCEGs atdistances of $\lesssim 100$ Mpc from the Hubble Space Telescope/Wide FieldCamera 3 F814W($I_{814}$)/F160W($H_{160}$) archival images. We find that mostof these MCEGs host a rich population of GCs with a color range of$0.0<(I_{814}-H_{160})_0<1.1$. The fractions of their red GCs range from$f_{RGC} =0.2$ to 0.7 with a mean of $f_{RGC} =0.48\pm0.14$. We divide the MCEGsample into two groups: one in clusters and the other in groups/fields. Themean red GC fraction of the cluster MCEGs is $0.60\pm0.06$, which is 0.2 largerthan the value of the group/field MCEGs, $0.40\pm0.10$. The value for thecluster MCEGs is $\sim$0.3 larger than the mean value of giant early-typegalaxies with similar stellar mass in the Virgo cluster ($f_{RGC}=0.33\pm0.13$). Our results show that most of the MCEGs in our sample areindeed relic galaxies. This further implies that a majority of the red GCs inMCEGs are formed early in massive galaxies and that most MCEGs in the localuniverse have rarely undergone mergers after they became red nuggets about 10Gyr ago.

We present a far-UV (FUV) study of the star-forming complexes (SFCs) in threenearby galaxies using the Ultraviolet Imaging Telescope (UVIT). The galaxiesare close to face-on and show significant outer disk star formation. Two ofthem are isolated (NGC 628, NGC 6946), and one is interacting with distantcompanions (NGC 5457). We compared the properties of the SFCs inside andoutside the optical radius (R$_{25}$). We estimated the sizes, star formationrates (SFRs), metallicities, and the Toomre Q parameter of the SFCs. We findthat the outer disk SFCs are at least ten times smaller in area than those inthe inner disk. The SFR per unit area ($\Sigma_{SFR}$) in both regions havesimilar mean values, but the outer SFCs have a much smaller range of$\Sigma_{SFR}$. They are also metal-poor compared to the inner disk SFCs. TheFUV emission is well correlated with the neutral hydrogen gas (\HI)distribution and is detected within and near several \HI~holes. Our estimationof the Q parameter in the outer disks of the two isolated galaxies suggeststhat their outer disks are stable (Q$>$1). However, their FUV images indicatethat there is ongoing star formation in these regions. This suggests that theremay be some non-luminous mass or dark matter in their outer disks, whichincreases the disk surface density and supports the formation of localgravitational instabilities. In the interacting galaxy, NGC 5457, the baryonicsurface density is sufficient (Q$<$1) to trigger local disk instabilities inthe outer disk.

A detailed study of the morphology of lenticular galaxies is an important wayto understand how this type of galaxy formed and evolves over time. Decomposinga galaxy into its components (disc, bulge, bar, ...) allows recovering thecolour gradients present in each system, its star formation history, and itsassembly history. We use GALFITM to perform a multi-wavelength structuraldecomposition of the closest lenticular galaxy, NGC 3115, resulting in thedescription of its stellar light into several main components: a bulge, a thindisc, a thick disc and also evidence of a bar. We report the finding of centralbluer stellar populations in the bulge, as compared to the colour of the galaxyoutskirts, indicating either the presence of an Active Galactic Nucleus (AGN)and/or recent star formation activity. From the spectral energy distributionresults, we show that the galaxy has a low luminosity AGN component, but evenexcluding the effect of the nuclear activity, the bulge is still bluer than theouter-regions of the galaxy, revealing a recent episode of star formation.Based on all of the derived properties, we propose a scenario for the formationof NGC 3115 consisting of an initial gas-rich merger, followed by accretionsand feedback that quench the galaxy, until a recent encounter with thecompanion KK084 that reignited the star formation in the bulge, provoked a coredisplacement in NGC 3115 and generated spiral-like features. This result isconsistent with the two-phase formation scenario, proposed in previous studiesof this galaxy.