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Enrichetta Iodice

Publications and source records attributed to Enrichetta Iodice.

At least 37 records · Page 2Linked to original sources

Does the virial mass drive the intra-cluster light? The relationship between the ICL and M$_{vir}$ from VEGAS

In this Letter we revisit the relationship between the fraction of the intra-cluster light (ICL) and both the virial mass and the fraction of Early Type Galaxies in the host halo. This is based on a statistically significant and homogeneous sample of 22 groups and clusters of galaxies in the local Universe ($z \leq 0.05$), 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 $μ_g$ $\geq$ 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 $\leq$ 0.05. The main result of this work is the 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 ( $\sim$ $10^{12.5} \leq M_{vir} \leq 10^{15.5} M_{\odot}$), in agreement with some theoretical studies. Since the new data points are all derived with the same methodology and from the same observational setup, and all have comparable depth, the large observed scatter indicates an intrinsic variation in the ICL fraction.On the other hand, there is a weak relation 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.

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The SAMI -- Fornax Dwarfs Survey II: The Stellar Mass Fundamental Plane and the Dark Matter fraction of Dwarf Galaxies

We explore the kinematic scaling relations of 38 dwarf galaxies in the Fornax Cluster using observations from the SAMI integral field spectrograph. We focus on the Fundamental Plane (FP), defined by the physical properties of the objects (scale length, surface brightness and velocity dispersion) and the Stellar Mass (Fundamental) Plane, where surface brightness is replaced by stellar mass, and investigate their dynamical-to-stellar-mass ratio. We confirm earlier results that the Fornax dEs are significantly offset above the FP defined by massive, hot stellar systems. For the Stellar Mass (Fundamental) Plane, which shows much lower scatter, we find that young and old dwarf galaxies lie at about the same distance from the plane, all with comparable scatter. We introduce the perpendicular deviation of dwarf galaxies from the Stellar Mass Plane defined by giant early-types as a robust estimate of their DM fraction, and find that the faintest dwarfs are systematically offset above the plane, implying that they have a higher dark matter fraction. This result is confirmed when estimating the dynamical mass of our dEs using a virial mass estimator, tracing the onset of dark matter domination in low mass stellar systems. We find that the position of our galaxies on the Stellar Mass FP agrees with the galaxies in the Local Group. This seems to imply that the processes determining the position of dwarf galaxies on the FP depend on the environment in the same way, whether the galaxy is situated in the Local Group or in the Fornax Cluster.

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Galaxy populations in the Hydra I cluster from the VEGAS survey II. The ultra-diffuse galaxy population

In this work, we extend the catalog of low-surface brightness (LSB) galaxies, including Ultra-Diffuse Galaxy (UDG) candidates, within $\approx 0.4R_{vir}$ 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 ($22.7 \lesssim μ_{0,g} \lesssim 26.5$ mag/arcsec$^2$), effective radius ($0.6 \lesssim R_e \lesssim 4.0$ kpc) and color ($0.4 \leq g-r \leq 0.9$ mag), and have stellar masses in the range $\sim 5\times 10^6 - 2\times 10^8$M$_{\odot}$. 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.

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The Fornax3D project: discovery of ancient massive merger events in the Fornax cluster galaxies NGC 1380 and NGC 1427

We report the discovery of ancient massive merger events in the early-type galaxies NGC 1380 and NGC 1427, members of the Fornax galaxy cluster. Both galaxies have been observed by the MUSE IFU instrument on the VLT, as part of the Fornax3D project. By fitting recently-developed population-orbital superposition models to the observed surface brightness as well as stellar kinematic, age, and metallicity maps, we obtain the stellar orbits, age and metallicity distributions of each galaxy. We then decompose each galaxy into multiple orbital-based components, including a dynamically hot inner stellar halo component which is identified as the relic of past massive mergers. By comparing to analogues from cosmological galaxy simulations, chiefly TNG50, we find that the formation of such a hot inner stellar halo requires the merger with a now-destroyed massive satellite galaxy of $3.7_{-1.5}^{+2.7} \times 10^{10}$ Msun (about $1/5$ of its current stellar mass) in the case of NGC 1380 and of $1.5_{-0.7}^{+1.6} \times10^{10}$ Msun (about $1/4$ of its current stellar mass) in the case of NGC 1427. Moreover, we infer that the last massive merger in NGC 1380 happened $\sim10$ Gyr ago based on the stellar age distribution of the re-grown dynamically cold disk, whereas the merger in NGC 1427 ended $t\lesssim 8$ Gyr ago based on the stellar populations in its hot inner stellar halo. The major merger event in NGC 1380 is the first one with both merger mass and merger time quantitatively inferred in a galaxy beyond the Local Volume. Moreover, it is the oldest and most massive merger uncovered in nearby galaxies so far.

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The intra-group baryons in the LEO I pair from the VST Early-type GAlaxy Survey

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 $\sim$ 3.9 square degrees around the pair, and the long integration time, we can map the light distribution out to $\sim$ 63 kpc and down to $\sim$ 30 mag/arcsec$^2$ in the $g$ band and $\sim$ 29 mag/arcsec$^2$ in the $r$ band, deeper than previous data available for this target. The map of the intra-group light (IGL) presents two very faint ($μ_g \sim$ 28-29 mag/arcsec$^2$) 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 IGL is $\sim 17 \pm 2\%$ in both $g$ and $r$ bands, with an average color $g$-$r$= $0.75 \pm 0.04$~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 \citet{Hartke2020} and \citet{Hartke2022arXiv220108710H}. 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.

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Galaxy populations in the Hydra I cluster from the VEGAS survey I. Optical properties of a large sample of dwarf galaxies

At ~50 Mpc, the Hydra I cluster of galaxies is among the closest cluster in the z=0 Universe, and an ideal environment to study dwarf galaxy properties in a cluster environment. We exploit deep imaging data of the Hydra I cluster to construct a new photometric catalog of dwarf galaxies in the cluster core, which is then used to derive properties of the Hydra I cluster dwarf galaxies population as well as to compare with other clusters. Moreover, we investigate the dependency of dwarf galaxy properties on their surrounding environment. The new Hydra I dwarf catalog contains 317 galaxies with luminosity between -18.5<$M_r$<-11.5 mag, a semi-major axis larger than ~200 pc (a=0.84 arcsec), of which 202 are new detections, previously unknown dwarf galaxies in the Hydra I central region. We estimate that our detection efficiency reaches 50% at the limiting magnitude $M_r$=-11.5 mag, and at the mean effective surface brightness $\overlineμ_{e,r}$=26.5 mag/$arcsec^2$. We present the standard scaling relations for dwarf galaxies and compare them with other nearby clusters. We find that there are no observational differences for dwarfs scaling relations in clusters of different sizes. We study the spatial distribution of galaxies, finding evidence for the presence of substructures within half the virial radius. We also find that mid- and high-luminosity dwarfs ($M_r$<-14.5 mag) become on average redder toward the cluster center, and that they have a mild increase in $R_e$ with increasing clustercentric distance, similar to what is observed for the Fornax cluster. No clear clustercentric trends are reported with surface brightness and Sérsic index. Considering galaxies in the same magnitude-bins, we find that for high and mid-luminosity dwarfs ($M_r$<-13.5 mag) the g-r color is redder for the brighter surface brightness and higher Sérsic n index objects.

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The Fornax Deep Survey (FDS) with VST XII: Low surface brightness dwarf galaxies in the Fornax cluster

In this work we use Max-Tree Objects, (MTO) on the FDS data in order to detect previously undetected Low surface brightness (LSB) galaxies. After extending the existing Fornax dwarf galaxy catalogs with this sample, our goal is to understand the evolution of LSB dwarfs in the cluster. We also study the contribution of the newly detected galaxies to the faint end of the luminosity function. We test the detection completeness and parameter extraction accuracy of MTO. We then apply MTO to the FDS images to identify LSB candidates. The identified objects are fitted with 2D Sérsic models using GALFIT and classified based on their morphological appearance, colors, and structure. With MTO, we are able to increase the completeness of our earlier FDS dwarf catalog (FDSDC) 0.5-1 mag deeper in terms of total magnitude and surface brightness. Due to the increased accuracy in measuring sizes of the detected objects, we also add many small galaxies to the catalog that were previously excluded as their outer parts had been missed in detection. We detect 265 new LSB dwarf galaxies in the Fornax cluster, which increases the total number of known dwarfs in Fornax to 821. Using the extended catalog, we show that the luminosity function has a faint-end slope of -1.38+/-0.02. We compare the obtained luminosity function with different environments studied earlier using deep data but do not find any significant differences. On the other hand, the Fornax-like simulated clusters in the IllustrisTNG cosmological simulation have shallower slopes than found in the observational data. We also find several trends in the galaxy colors, structure, and morphology that support the idea that the number of LSB galaxies is higher in the cluster center due to tidal forces and the age dimming of the stellar populations. The same result also holds for the subgroup of large LSB galaxies, so-called ultra-diffuse galaxies.

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Formation of an ultra-diffuse galaxy in the stellar filaments of NGC3314A: caught in act?

The VEGAS imaging survey of the Hydra I cluster reveals an extended network of stellar filaments to the south-west of the spiral galaxy NGC3314A. Within these filaments, at a projected distance of ~40 kpc from the galaxy, we discover an ultra-diffuse galaxy (UDG) with a central surface brightness of $μ_{0,g}\sim26$ mag arcsec$^{-2}$ and effective radius $R_e\sim3.8$ kpc. This UDG, named UDG32, is one of the faintest and most diffuse low-surface brightness galaxies in the Hydra~I cluster. Based on the available data, we cannot exclude that this object is just seen in projection on top of the stellar filaments, thus being instead a foreground or background UDG in the cluster. However, the clear spatial coincidence of UDG32 with the stellar filaments of NGC3314A suggests that it might have formed from the material in the filaments, becoming a detached, gravitationally bound system. In this scenario, the origin of UDG32 depends on the nature of the stellar filaments in NGC3314A, which is still unknown. They could result from ram-pressure stripping or have a tidal origin. In this letter, we focus on the comparison of the observed properties of the stellar filaments and UDG32, and speculate about their possible origin. The relatively red color ($g-r=0.54 \pm 0.14$~mag) of the UDG, similar to that of the disk in NGC3314A, combined with an age older than 1Gyr, and the possible presence of a few compact stellar systems, all point towards a tidal formation scenario inferred for the UDG32.

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The VST Early-type GAlaxy Survey: Exploring the Outskirts and Intra-cluster Regions of Galaxies in the Low-surface-brightness Regime

The VST Early-type GAlaxy Survey (VEGAS) is a deep, multi-band (u, g, r, i) imaging survey, carried out with the 2.6-metre VLT Survey Telescope (VST) at ESO's Paranal Observatory in Chile. VEGAS combines the wide (1-square-degree) OmegaCAM imager and long integration times, together with a specially designed observing strategy. It has proven to be a gold mine for studies of features at very low surface brightness, down to levels of mu_g~27-30 magnitudes arcsec^(-2), over 5-8 magnitudes fainter than the dark sky at Paranal. In this article we highlight the main science results obtained with VEGAS observations of galaxies across different environments, from dense clusters of galaxies to unexplored poor groups and in the field.

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VEGAS: A VST Early-type GAlaxy Survey.VI. The diffuse light in HCG 86 from the ultra-deep VEGAS images

Context. In this paper we present ultra deep images of the compact group of galaxies HCG 86 as part of the VEGAS survey. Aims. Our main goals are to estimate the amount of intragroup light (IGL), to study the light and color distributions in order to address the main formation process of the IGL component in groups of galaxies. Methods. We derived the azimuthally averaged surface brightness profiles in the g,r and i bands with g - r and r - i average colors and color profiles for all group members. By fitting the light distribution, we have extrapolated the contribution of the stellar halos plus the diffuse light from the brightest component of each galaxy. The results are compared with theoretical predictions. Results. The long integration time and wide area covered make our data deeper than previous literature studies of the IGL in compact groups of galaxies and allow us to produce an extended (~160 kpc) map of the IGL, down to a surface brightness level of about 30 mag/arcsec^2 in the g band. The IGL in HCG 86 is mainly in diffuse form and has average colors of g - r ~ 0.8 mag and r - i ~ 0.4 mag. The fraction of IGL in HCG 86 is ~ 16% of the total luminosity of the group, and this is consistent with estimates available for other compact groups and loose groups of galaxies of similar virial masses. A weak trend is present between the amount of IGL and the early-type to late-type galaxy ratio. Conclusions. By comparing the IGL fraction and colors with those predicted by simulations, the amount of IGL in HCG 86 would be the result of the disruption of satellites at an epoch of z ~ 0.4. At this redshift, observed colors are consistent with the scenario where the main contribution to the mass of the IGL comes from the intermediate-massive galaxies.

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On the assembly history of massive galaxies. A pilot project with VEGAS deep imaging and M3G integral field spectroscopy

In this paper we present the new deep images from the VEGAS survey of three massive ($M_{*} \simeq 10^{12}$~M$_\odot$) galaxies from the MUSE Most Massive Galaxies (M3G) project, with distances in the range $151\leq D \leq 183$ Mpc: PGC007748, PGC015524 and PGC049940. The long integration time and the wide field of view of OmegaCam@VST allowed us to map the light and color distributions down to $μ_g\simeq30$~mag/arcsec$^2$ and out to $\sim 2R_e$. The deep data are crucial to estimate the contribution of the different galaxy's components, in particular the accreted fraction in the stellar halo. The available integral-field observations with MUSE cover a limited portion of each galaxy (out to $\sim 1R_e$), but, from the imaging analysis we find that they map the kinematics and stellar population beyond the first transition radius, where the contribution of the accreted component starts to dominate. The main goal of this work is to correlate the scales of the different components derived from the image analysis with the kinematics and stellar population profiles from the MUSE data. Results were used to address the assembly history of the three galaxies with the help of the theoretical predictions. Our results suggest that PGC049940 has the lowest accreted mass fraction of 77%. The higher accreted mass fraction estimated for PGC007748 and PGC015524 (86% and 89%, respectively), combined with the flat $λ_R$ profiles suggest that a great majority of the mass has been acquired through major mergers, which have also shaped the shallower metallicity profiles observed at larger radii.

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AlFoCS + F3D II: unexpectedly low gas-to-dust ratios in the Fornax galaxy cluster

We combine observations from ALMA, ATCA, MUSE, andHerschel to study gas-to-dust ratios in 15 Fornax cluster galaxies detected in the FIR/sub-mm by Herschel and observed by ALMA as part of the ALMA Fornax Cluster Survey (AlFoCS). The sample spans a stellar mass range of 8.3 $\leq$ log (M$_*$ / M$_\odot$) $\leq$ 11.16, and a variety of morphological types. We use gas-phase metallicities derived from MUSE observations (from the Fornax3D survey) to study these ratios as a function of metallicity, and to study dust-to-metal ratios, in a sub-sample of nine galaxies. We find that gas-to-dust ratios in Fornax galaxies are systematically lower than those in field galaxies at fixed stellar mass/metallicity. This implies that a relatively large fraction of the metals in these Fornax systems is locked up in dust, which is possibly due to altered chemical evolution as a result of the dense environment. The low ratios are not only driven by HI deficiencies, but H$_2$-to-dust ratios are also significantly decreased. This is different in the Virgo cluster, where low gas-to-dust ratios inside the virial radius are driven by low HI-to-dust ratios, while H$_2$-to-dust ratios are increased. Resolved observations of NGC1436 show a radial increase in H$_2$-to-dust ratio, and show that low ratios are present throughout the disc. We propose various explanations for the low H$_2$-to-dust ratios in the Fornax cluster, including the more efficient stripping of H$_2$ compared to dust, more efficient enrichment of dust in the star formation process, and altered ISM physics in the cluster environment.

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The Fornax Deep Survey data release 1

We present the first data release of the Fornax Deep Survey (FDS), an imaging survey using using the wide-field imager OmegaCAM mounted on the VST in the SDSS u', g', r', and i'-bands covering the Fornax Galaxy Cluster and the infalling Fornax A Group. FDS is a joint project between NOVA (previously called FOCUS - PI: R. F. Peletier) and INAF (as part of VEGAS - PIs: M. Capaccioli and E. Iodice). With exposure times of about 9 hours over an area of ~28 square degrees, this survey is a legacy dataset for studies of members of the Fornax Galaxy Cluster and the infalling Fornax A Group down to a surface brightness limit of ~28 mag/arcsec^2 (1-sigma surface brightness over a 1 arcsecond^2 area) and opens a new parameter regime to investigate the role of the cluster environment in shaping the properties of its galaxy population. After the Virgo cluster,Fornax is the second nearest galaxy cluster to us, and with its different mass and evolutionary state, it provides a valuable comparison that makes it possible to understand the various evolutionary effects on galaxies and galaxy clusters. Details about the survey can be found in A. Venhola, R. F. Peletier, E. Laurikainen et al., 2018, A&A 620, 165. In this release, 181 Gb of (compressed) fits files reduced using the system are present. Catalogues with the complete sample of sources including dwarf galaxies part of the cluster, globular clusters, and background galaxies will be provided in forthcoming releases. The data products are available via the ESO Science Portal at https://archive.eso.org/scienceportal/home?publ_date=2020-08-26

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The SAMI -- Fornax Dwarfs Survey I: Sample, observations and the specific stellar angular momentum of dwarf elliptical galaxies

Dwarf ellipticals are the most common galaxy type in cluster environments, however the challenges associated with their observation mean their formation mechanisms are still poorly understood. To address this, we present deep integral field observations of a sample of 31 low-mass ($10^{7.5} <$ M$_\star < 10^{9.5}$ M$_\odot$) early-type galaxies in the Fornax cluster with the SAMI instrument. For 21 galaxies our observations are sufficiently deep to construct spatially resolved maps of the stellar velocity and velocity dispersion - for the remaining galaxies we extract global velocities and dispersions from aperture spectra only. From the kinematic maps we measure the specific stellar angular momentum $λ_R$ of the lowest mass dE galaxies to date. Combining our observations with early-type galaxy data from the literature spanning a large range in stellar mass, we find that $λ_R$ decreases towards lower stellar mass, with a corresponding increase in the proportion of slowly rotating galaxies in this regime. The decrease of $λ_R$ with mass in our sample dE galaxies is consistent with a similar trend seen in somewhat more massive spiral galaxies from the CALIFA survey. This suggests that the degree of dynamical heating required to produce dEs from low-mass starforming progenitors may be relatively modest, and consistent with a broad range of formation mechanisms.

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AlFoCS + Fornax3D: resolved star formation in the Fornax cluster with ALMA and MUSE

We combine data from ALMA and MUSE to study the resolved (~300 pc scale) star formation relation (star formation rate vs. molecular gas surface density) in cluster galaxies. Our sample consists of 9 Fornax cluster galaxies, including spirals, ellipticals, and dwarfs, covering a stellar mass range of ~10^8.8 - 10^11 M_Sun. CO(1-0) and extinction corrected Halpha were used as tracers for the molecular gas mass and star formation rate, respectively. We compare our results with Kennicutt (1998) and Bigiel et al. (2008). Furthermore, we create depletion time maps to reveal small-scale variations in individual galaxies. We explore these further in FCC290, using the 'uncertainty principle for star formation' (Kruijssen & Longmore, 2014a) to estimate molecular cloud lifetimes, which we find to be short (<10 Myr) in this galaxy. Galaxy-averaged depletion times are compared with other parameters such as stellar mass and cluster-centric distance. We find that the star formation relation in the Fornax cluster is close to those from Kennicutt (1998) and Bigiel et al. (2008}), but overlaps mostly with the shortest depletion times predicted by Bigiel et al. (2008). This slight decrease in depletion time is mostly driven by dwarf galaxies with disturbed molecular gas reservoirs close to the virial radius. In FCC90, a dwarf galaxy with a molecular gas tail, we find that depletion times are a factor >~10 higher in its tail than in its stellar body.

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Ultra Diffuse Galaxies in the IC1459 Group from the VEGAS Survey

Using deep g,r,i imaging from the VEGAS survey, we have searched for ultra diffuse galaxies (UDGs) in the IC 1459 group. Assuming they are group members, we identify 9 galaxies with physical sizes and surface brightnesses that match the UDG criteria within our measurement uncertainties. They have mean colours of g--i = 0.6 and stellar masses of $\sim$10$^8$ M$_{\odot}$. Several galaxies appear to have associated systems of compact objects, e.g. globular clusters. Two UDGs contain a central bright nucleus, with a third UDG revealing a remarkable double nucleus. This appears to be the first reported detection of a double nucleus in a UDG - its origin is currently unclear.

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A spectroscopic census of the Fornax cluster and beyond: preparing for next generation surveys

The Fornax cluster is the nearest, large cluster in the southern sky, and is currently experiencing active assembly of mass. It is thus the target of a number of ongoing observing campaigns at optical, near-infrared and radio wavelengths, using state-of-the-art facilities in the Southern hemisphere. Spectroscopic redshifts are essential not only for determining cluster membership, but also kinematics within the cluster and identifying substructures. We present a compilation of all available major spectroscopic campaigns undertaken within the Fornax region, including new and previously unpublished spectroscopy. This provides not only a comprehensive census of Fornax cluster membership as a resource for the many ongoing studies of this dynamic system, but also probes the large scale structure in the background volume.

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Constraining nuclear star cluster formation using MUSE-AO observations of the early-type galaxy FCC47

Nuclear star clusters (NSCs) are found in at least 70% of all galaxies, but their formation path is still unclear. In the most common scenarios, NSCs form in-situ from the galaxy's central gas reservoir, through merging of globular clusters (GCs), or through a combination of the two. As the scenarios pose different expectations for angular momentum and stellar population properties of the NSC in comparison to the host galaxy and the GC system, it is necessary to characterise the stellar light, NSC and GCs simultaneously. The large NSC (r$_\rm{eff} = 66$ pc) and rich GC system of the early-type Fornax cluster galaxy FCC47 (NGC1336) render this galaxy an ideal laboratory to constrain NSC formation. Using MUSE science verification data assisted by adaptive optics, we obtained maps for the stellar kinematics and for stellar-population properties of FCC47. We extracted the spectra of the central NSC and determined line-of-sight velocities of 24 GCs and metallicities of five. FCC47 shows two decoupled components (KDCs): a rotating disk and the NSC. Our orbit-based dynamical Schwarzschild model revealed that the NSC is a distinct kinematic feature and it constitutes the peak of metallicity and old ages in the galaxy. The main body consists of two counter-rotating populations and is dominated by a more metal-poor population. The GC system is bimodal with a dominant metal-poor population and the total GC system mass is $\sim 17\%$ of the NSC mass ($\sim$ 7 $\times$ $10^8 M_\odot$). The rotation, high metallicity and high mass of the NSC cannot be uniquely explained by GC-inspiral and most likely requires additional, but quickly quenched, in-situ formation. The presence of two KDCs most probably are evidence of a major merger that has altered the structure of FCC47 significantly, indicating the important role of galaxy mergers in forming the complex kinematics in the galaxy-NSC system.

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