Duncan A. Forbes’s research while affiliated with Swinburne University of Technology and other places

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Publications (603)


A new class of dark matter-free dwarf galaxies? I. Clues from FCC 224, NGC 1052-DF2 and NGC 1052-DF4
  • Preprint

February 2025

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Duncan A. Forbes

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Lucas M. Valenzuela

The discovery of quiescent, dark matter (DM)-deficient ultra-diffuse galaxies (UDGs) with overluminous globular clusters (GCs) has challenged galaxy formation models within the Lambda Cold Dark Matter (Λ\LambdaCDM) cosmological paradigm. Previously, such galaxies were only identified in the NGC 1052 group, raising the possibility that they are the result of unique, group-specific processes, and limiting their broader significance. The recent identification of FCC 224, a putative DM-deficient UDG on the outskirts of the Fornax Cluster, suggests that such galaxies are not confined to the NGC 1052 group but rather represent a broader phenomenon. We aim to investigate the DM content of FCC 224 and to explore its similarities to the DM-free dwarfs in the NGC 1052 group, DF2 and DF4, to determine whether or not it belongs to the same class of DM-deficient UDGs. We use high-resolution Keck Cosmic Web Imager (KCWI) spectroscopy to study the kinematics, stellar populations, and GC system of FCC 224, enabling direct comparisons with DF2 and DF4. We find that FCC 224 is also DM-deficient and exhibits a distinct set of traits shared with DF2 and DF4, including slow and prolate rotation, quiescence in low-density environments, coeval formation of stars and GCs, flat stellar population gradients, a top-heavy GC luminosity function, and monochromatic GCs. These shared characteristics signal the existence of a previously unrecognized class of DM-deficient dwarf galaxies. This diagnostic framework provides a means of identifying additional examples and raises new questions for galaxy formation models within Λ\LambdaCDM cosmology.


Looking into the faintEst WIth MUSE (LEWIS): Exploring the nature of ultra-diffuse galaxies in the Hydra-I cluster. II. Stellar kinematics and dynamical masses.

February 2025

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1 Read

Astronomy and Astrophysics

This paper focuses on a class of galaxies characterised by an extremely low surface brightness: ultra-diffuse galaxies (UDGs). We used new integral-field (IF) spectroscopic data, obtained with the ESO Large Programme Looking into the faintEst WIth MUSE (LEWIS). It provides the first homogeneous IF spectroscopic survey performed by MUSE at the Very Large Telescope of a complete sample of UDGs and low-surface-brightness galaxies within a virial radius of 0.4 in the Hydra I cluster, according to the UDG abundance-halo mass relation. Our main goals are addressing the possible formation channels for this class of objects and investigating possible correlations of their observational properties, including the stacked (1D) and spatially resolved (2D) stellar kinematics. In particular, we derive the stellar velocity dispersion from the stacked spectrum integrated within the effective radius ( and measure the velocity map of the galaxies in LEWIS. These quantities are used to estimate their dynamical mass ( Mdyn). We extracted the 1D stacked spectrum inside the effective radius ( which guarantees a high signal-to-noise ratio, to obtain an unbiased measure of To derive the spatially resolved stellar kinematics, we first applied the Voronoi tessellation algorithm to bin the spaxels in the datacube, and then we derived the stellar kinematics in each bin, following the same prescription as adopted for the 1D case. We extracted the velocity profiles along the galaxy major and minor axes and measured the semi-amplitude (Δ V) of the velocity curve. We found that 7 out of 18 UDGs in LEWIS show a mild rotation (Δ V ∼ 25- 40,km s^-1), 5 lack evidence of any rotation, and the remaining 6 UDGs are unconstrained cases. This is the first large census of velocity profiles for UDGs. The UDGs in LEWIS are characterised by low values of 30 km s^-1) on average, which is comparable with available values from the literature. Two objects show higher values of (∼ 30-40 km s^-1). These higher values might reasonably be due to the fast rotation observed in these galaxies, which affects the values of In the Faber-Jackson relation plane, we found a group of UDGs consistent with the relation within the error bars. Outliers of the Faber-Jackson relation are objects with a non-negligible rotation component. The UDGs and LSB galaxies in the LEWIS sample have a larger dark matter (DM) content on average than dwarf galaxies ( V eff ∼ 10-100 M_⊙/L_⊙) with a similar total luminosity. We do not find clear correlations between the derived structural properties and the local environment. By mapping the stellar kinematics for a homogenous sample of UDGs in a cluster environment, we found a significant rotation for many galaxies. Therefore, two classes of UDGs are found in the Hydra I cluster based on the stellar kinematics: rotating and non-rotating systems. This result, combined with the DM content and the upcoming analysis of the star formation history and globular cluster population, can help us to distinguish between the several formation scenarios proposed for UDGs.


Looking into the faintEst WIth MUSE (LEWIS): Exploring the nature of ultra-diffuse galaxies in the Hydra-I cluster II. Stellar kinematics and dynamical masses

January 2025

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3 Reads

Context: This paper focuses on a class of galaxies characterised by an extremely low surface brightness: the ultra-diffuse galaxies (UDGs). We used new integral-field spectroscopic data from the ESO Large Programme Looking into the faintEst WIth MUSE (LEWIS) project. Aims: Our main goals are addressing the formation channels and investigating possible correlations of their observational properties. In particular, we derive their stellar kinematics and dynamical properties. Methods: We extract the 1D stacked spectrum inside the effective radius to obtain an unbiased measure of σeff\sigma_{\rm eff}. To derive the spatially-resolved stellar kinematics, we first apply the Voronoi tessellation algorithm to bin the spaxels in the datacube and then follow the same prescription adopted for the 1D case. In addition, we extract the velocity profiles along the galaxy's major and minor axes. Results: We find that 7 out of 18 UDGs in LEWIS show a mild rotation, 5 do not have evidence of any rotation, and the remaining 6 UDGs are unconstrained cases. This is the first large census of velocity profiles for UDGs. On average, UDGs in LEWIS are characterised by low values of σeff\sigma_{\rm eff}, comparable with available values from the literature. In the Faber-Jackson relation plane, we found a group of UDGs consistent with the relation within the errorbars, whereas outliers are objects with non-negligible rotation components. UDGs and LSBs in LEWIS have larger dark matter content than dwarf galaxies with similar total luminosity. We do not find clear correlations between the derived properties and the local environment. Conclusions: Based on the stellar kinematics, two classes of UDGs are found in the Hydra I cluster: the rotating and non-rotating systems. This result, combined with other structural properties, can help to discriminate between the several formation scenarios proposed for UDGs.


Looking into the faintEst WIth MUSE (LEWIS): Exploring the nature of ultra-diffuse galaxies in the Hydra I cluster III. Untangling UDG 32 from the stripped filaments of NGC 3314A with multi-wavelength data

January 2025

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4 Reads

UDG 32 is an ultra-diffuse galaxy (UDG) candidate in the Hydra I cluster that was discovered in the extended network of stellar filaments of the jellyfish galaxy NGC 3314A. This galaxy is affected by ram pressure stripping and it is hypothesised that UDG 32 may have formed from its stripped material. In this paper, we address whether UDG 32 can be associated with the stripped material of NGC 3314A and constrain its formation scenario in relation to its environment. We use new integral-field spectroscopic data from the MUSE large programme `LEWIS' in conjunction with deep multi-band photometry to constrain the kinematics and stellar populations of UDG 32. The new MUSE data allow us to reveal that the stripped material from NGC 3314A, traced by emission lines such as Hα\alpha, extends much further from its parent galaxy than previously known, completely overlapping with UDG 32 in projection, and with ram pressure induced star formation. We determine the line-of-sight velocity of UDG 32 (vLOS=3080±120v_{\rm LOS} = 3080\pm120 km/s) and confirm that UDG 32 is part of the same kinematic structure as NGC 3314A, the Hydra I cluster south-east subgroup. By fitting the UV and optical spectral energy distribution, we constrain the stellar population properties of UDG 32. We determine its mass-weighted age to be 7.72.8+2.97.7^{+2.9}_{-2.8} Gyr and its metallicity to be [M/H] = 0.070.32+0.190.07^{+0.19}_{-0.32} dex. We confirm the presence of two globular clusters (GCs) in the MUSE field of view, bound to the Hydra I cluster rather than to UDG 32, thus part of the Hydra I intracluster GC population. The metal-rich and intermediate-age nature of UDG 32 points towards its formation from pre-enriched material in the south-east group of the Hydra I cluster that was liberated from a more massive galaxy via tidal or ram-pressure stripping, but we cannot establish a direct link to the ram-pressure stripped material from NGC 3314A.


Fig. 3. Age (top) and metallicity (bottom) profiles of observed LSB dwarfs (coloured lines), compared to the average trends of quiescent cluster UDGs in the TNG50 simulations (dotted lines and dark grey shading) and field UDGs from NIHAO (dashed line and light grey shading). Solid lines show tidally stripped UDGs from TNG50. While observed age profiles are mostly flat, as in the simulations, the metallicity profiles show a divergence, particularly at larger radii.
Signs of `Everything Everywhere All at Once' formation in low-surface-brightness globular-cluster-rich dwarf galaxies
  • Article
  • Full-text available

January 2025

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1 Read

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2 Citations

Astronomy and Astrophysics

Context. Only two ultra-diffuse galaxies (UDGs) have spatially resolved stellar population properties, showing flat to rising metallicity profiles, indicative of a different formation pathway than most dwarf galaxies. The scarcity of other low-surface-brightness (LSB) dwarfs with a similar analysis prevents a deeper understanding of this behaviour. Aims. We investigated the radial profiles of the ages, metallicities, and star formation histories of four globular cluster (GC)-rich LSB dwarfs, newly observed as part of the ‘Analysis of Galaxies At The Extremes’ (AGATE) collaboration. DFX1 and DF07 are bona fide UDGs, while PUDG-R27 and VCC 1448 are ‘nearly UDGs’. Comparing their and DF44’s properties to simulations, we aim to reveal their formation pathways. Methods. We used the full-spectral-fitting code pPXF to fit different spectra extracted in annular apertures in a bid to recover the stellar population properties and compute their gradients. We compared these results with a sample of literature classical dwarfs and simulations, in particular simulated UDGs. Results. Our five LSB dwarfs have flat age and flat to rising metallicity profiles. Such age gradients are compatible with those of classical dwarfs (observed and from cosmological simulations), but the metallicity gradient diverges. All of our LSB dwarfs (except for PUDG-R27, which shows a pronounced increasing metallicity) are compatible with being on the extreme tail of the age–metallicity gradient relation, suggesting a coeval formation, forming the galaxy all at once. Conclusions. This sample of GC-rich LSB dwarfs with spatially resolved properties provides further evidence that they follow a different formation path than classical dwarfs. However, larger samples with higher-S/N spectra and varying amounts of GC richness are required to set robust constraints on the formation pathways of LSB dwarf galaxies.

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An Unexplained Origin for the Unusual Globular Cluster System in the Ultra-diffuse Galaxy FCC 224

January 2025

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2 Reads

We study the quiescent ultra-diffuse galaxy FCC 224 in the Fornax cluster using Hubble Space Telescope (HST) imaging, motivated by peculiar properties of its globular cluster (GC) system revealed in shallower imaging. The surface brightness fluctuation distance of FCC 224 measured from HST is 18.6±2.718.6 \pm 2.7 Mpc, consistent with the Fornax Cluster distance. We use Prospector to infer the stellar population from a combination of multi-wavelength photometry (HST, ground-based, WISE) and Keck Cosmic Web Imager spectroscopy. The galaxy has a mass-weighted age of \sim 10 Gyr, metallicity [M/H] of 1.25\sim -1.25 dex, and a very short formation e-folding time of τ0.3\tau \sim 0.3 Gyr. Its 12 candidate GCs exhibit highly homogeneous g475I814g_{\rm 475}-I_{\rm 814} colors, merely 0.04 mag bluer than the diffuse starlight, which supports a single burst formation scenario for this galaxy. We confirm a top-heavy GC luminosity function, similar to the two dark matter deficient galaxies NGC 1052-DF2 and DF4. However, FCC 224 differs from those galaxies with relatively small GC sizes of \sim 3 pc (35%\sim 35\% smaller than typical for other dwarfs), and with radial mass segregation in its GC system. We are not yet able to identify a formation scenario to explain all of the GC properties in FCC 224. Follow-up measurements of the dark matter content in FCC 224 will be crucial because of the mix of similarities and differences among FCC 224, DF2, and DF4.


Globular cluster ages and their relation to high-redshift stellar cluster formation times from different globular cluster models

January 2025

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5 Reads

Monthly Notices of the Royal Astronomical Society

The formation details of globular clusters (GCs) are still poorly understood due to their old ages and the lack of detailed observations of their formation. A large variety of models for the formation and evolution of GCs have been created to improve our understanding of their origins, based on GC properties observed at z = 0. We present the first side-by-side comparison of six current GC formation models with respect to their predictions for the GC ages and formation redshifts in Milky Way (MW)-like galaxies. We find that all the models are capable of forming most of the surviving GCs at more than 10 Gyr ago, in general agreement with the observation that most GCs are old. However, the measured MW GC ages are still systematically older than those predicted in the galaxies of four of the models. Investigating the variation of modelled GC age distributions for general MW-mass galaxies, we find that some of the models predict that a significant fraction of MW-mass galaxies would entirely lack a GC population older than 10 Gyr, whereas others predict that all MW-mass galaxies have a significant fraction of old GCs. This will have to be further tested in upcoming surveys, as systems without old GCs in that mass range are currently not known. Finally, we show that the models predict different formation redshifts for the oldest surviving GCs, highlighting that models currently disagree about whether the recently observed young star clusters at high redshifts could be the progenitors of today’s GCs.


Signs of `Everything Everywhere All At Once' formation in low surface brightness globular cluster-rich dwarf galaxies

January 2025

Only two ultra-diffuse galaxies (UDGs) have spatially resolved stellar population properties, both showing radially flat-to-rising metallicity profiles, indicative of a different formation pathway to most dwarf galaxies. The scarcity of other low surface brightness (LSB) dwarfs with a similar analysis prevents a deeper understanding on this behaviour. We investigate the radial profiles of the ages, metallicities and star formation histories of four globular cluster (GC) rich LSB dwarfs, newly observed within the 'Analysis of Galaxies At The Extremes' (AGATE) collaboration. DFX1 and DF07 are bona-fide UDGs, while PUDG-R27 and VCC1448 are nearly UDGs (NUDGes). Comparing their and DF44's results to simulations, we aim to reveal their formation pathways. We use pPXF to fit different spectra extracted in annular apertures to recover the stellar population properties and compute their gradients. We compare those with a sample of literature classical dwarfs and simulations, in particular with simulated UDGs. Our five LSB dwarfs present flat age and flat-to-rising metallicity profiles. The flat age gradients are compatible with those of classical dwarfs (both observed and from cosmological simulations), but the metallicity gradient diverges. All of our LSB dwarfs (except for PUDG-R27, showing a pronounced increasing metallicity profile) are compatible with being the extreme tail of the age-metallicity gradient relation, with a preference to co-eval formation forming the galaxy all at once. This sample of GC-rich LSB dwarfs with spatially resolved properties confirms that they seem to follow a different formation path than classical dwarfs. However, larger samples with higher S/N spectra and varying amounts of GC richness are required to set robust constraints on the formation pathways of LSB dwarf galaxies.


Why do some Ultra Diffuse Galaxies have Rich Globular Cluster Systems?

December 2024

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6 Reads

Some ultra diffuse galaxies (UDGs) reveal many more globular clusters (GCs) than classical dwarf galaxies of the same stellar mass. These UDGs, with a mass in their GC system (MGC_{GC}) approaching 10\% of their host galaxy stellar mass (M_{\ast}), are also inferred to have high halo mass to stellar mass ratios (Mhalo_{halo}/M_{\ast}). They have been dubbed Failed Galaxies. It is unknown what role high GC formation efficiencies and/or low destruction rates play in determining the high MGC_{GC}/M_{\ast} ratios of some UDGs. Here we present a simple model, which is informed by recent JWST observations of lensed galaxies and by a simulation in the literature of GC mass loss and tidal disruption in dwarf galaxies. With this simple model, we aim to constrain the effects of GC efficiency/destruction on the observed GC richness of UDGs and their variation with the integrated stellar populations of UDGs. We assume no ongoing star formation (i.e. quenching at early times) and that the disrupted GCs contribute their stars to those of the host galaxy. We find that UDGs, with high MGC_{GC}/M_{\ast} ratios today, are most likely the result of very high GC formation efficiencies combined with modest rates of GC destruction. The current data loosely follow the model that ranges from the mean stellar population of classical dwarfs to that of metal-poor GCs as MGC_{GC}/M_{\ast} increases. As more data becomes available for UDGs, our simple model can be refined and tested further.


A Census of Dwarf Galaxy Satellites around LMC-mass Galaxy NGC 2403*

December 2024

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1 Citation

The Astrophysical Journal

We present the first comprehensive census of the satellite population around a Large Magellanic Cloud stellar-mass galaxy, as part of the Magellanic Analog Dwarf Companions and Stellar Halos (MADCASH) survey. We have surveyed NGC 2403 ( D = 3.0 Mpc) with the Subaru/Hyper Suprime-Cam imager out to a projected radius of 90 kpc (with partial coverage extending out to ∼110 kpc, or ∼80% of the virial radius of NGC 2403), resolving stars in the uppermost ∼2.5 mag of its red giant branch. By looking for stellar overdensities in the red giant branch spatial density map, we identify 149 satellite candidates, of which only the previously discovered MADCASH J074238+65201-dw is a bona fide dwarf, together with the more massive and disrupting satellite DDO 44. We carefully assess the completeness of our search via injection of artificial dwarf galaxies into the images, finding that we are reliably sensitive to candidates down to M V ∼ −7.5 mag (and somewhat sensitive to even fainter satellites). A comparison of the satellite luminosity function of NGC 2403 down to this magnitude limit to theoretical expectations shows overall good agreement. This is the first of a full sample of 11 Magellanic Cloud–mass host galaxies we will analyze, creating a statistical sample that will provide the first quantitative constraints on hierarchical models of galaxy formation around low-mass hosts.


Citations (47)


... However, it is very expensive to obtain good-quality spectroscopic data for UDGs even with 10 meter-class telescopes. To date, only ≤100 UDGs have been spectroscopically observed , and most of them are cluster UDGs (e.g., van Dokkum et al., 2015bvan Dokkum et al., , 2016Martínez-Delgado et al., 2016;Trujillo et al., 2017;Kadowaki et al., 2017;Gu et al., 2018;Ferré-Mateu et al., 2018;Ruiz-Lara et al., 2018;Buzzo et al., 2022Buzzo et al., , 2024aGannon et al., 2024;Shen et al., 2024). These cluster UDGs are mainly dominated by old and metal-poor populations (Kadowaki et al., 2017;Ferré-Mateu et al., 2018;Ruiz-Lara et al., 2018;Iodice et al., 2023). ...

Reference:

Searching for Nearby Diffuse Dwarf Galaxies in the COSMOS Field
The multiple classes of ultra-diffuse galaxies: Can we tell them apart?
  • Citing Article
  • December 2024

Monthly Notices of the Royal Astronomical Society

... NGC 300 is one of the targets selected by the DE-Cam Local Volume Exploration survey (DELVE; Drlica-Wagner et al. 2021, a long-term imaging program conducted with the Dark Energy Camera (DECam) on the Blanco 4m telescope (Flaugher et al. 2015). The DELVE-DEEP sub-survey was designed to image four relatively isolated LMC and SMC (Small Magellanic Cloud) analogs within the Local Volume, out to their estimated virial radii (complementary to the MADCASH survey; Carlin et al. 2016Carlin et al. , 2024. This approach aims to identify stellar substructures and smaller satellite companions with resolved stars, probing the hierarchical assembly of dwarf galaxies. ...

A Census of Dwarf Galaxy Satellites around LMC-mass Galaxy NGC 2403*
  • Citing Article
  • December 2024

The Astrophysical Journal

... Their host galaxies are expected to grow to be MW-like galaxies. For an overview of the current high-redshift observations of star clusters, see Pfeffer et al. (2024). ...

Comparing E-MOSAICS predictions of high-redshift proto-globular clusters with JWST observations in lensed galaxies
  • Citing Preprint
  • October 2024

... However, in cluster environments, the situation varies. While some GC distributions are consistent with those reported by Marleau et al. (2024b), other studies have found more extended GC systems relative to their host galaxies, with e,GC / e,gal ∼ 1.5 (e.g., van Dokkum et al. 2017;Lim et al. 2018;Janssens et al. 2024). In contrast, some studies report more concentrated GC distributions (e.g., Saifollahi et al. 2022Saifollahi et al. , 2024. ...

The PIPER survey. II. The globular cluster systems of low surface brightness galaxies in the Perseus cluster
  • Citing Article
  • September 2024

Monthly Notices of the Royal Astronomical Society

... Both galaxies have H i emission, with NGC 3314A exhibiting a complex velocity field with two distinct tails (Hess et al. 2022). The galaxy is part of a late-type galaxy group around NGC 3312 that interacts with the Hydra I cluster (Christlein & Zabludoff 2003;Wang et al. 2021;Hess et al. 2022;Spavone et al. 2024). Hess et al. (2022) estimate NGC 3314A to be ∼ 800 kpc and NGC 3312 at ∼ 550 kpc from the cluster centre and propose that the foreground group is moving towards us having already passed the cluster pericentre. ...

Galaxy populations in the Hydra I cluster from the VEGAS survey. III. The realm of low surface brightness features and intra-cluster light

Astronomy and Astrophysics

... However, it is very expensive to obtain good-quality spectroscopic data for UDGs even with 10 meter-class telescopes. To date, only ≤100 UDGs have been spectroscopically observed , and most of them are cluster UDGs (e.g., van Dokkum et al., 2015bvan Dokkum et al., , 2016Martínez-Delgado et al., 2016;Trujillo et al., 2017;Kadowaki et al., 2017;Gu et al., 2018;Ferré-Mateu et al., 2018;Ruiz-Lara et al., 2018;Buzzo et al., 2022Buzzo et al., , 2024aGannon et al., 2024;Shen et al., 2024). These cluster UDGs are mainly dominated by old and metal-poor populations (Kadowaki et al., 2017;Ferré-Mateu et al., 2018;Ruiz-Lara et al., 2018;Iodice et al., 2023). ...

A Catalogue and Analysis of Ultra-Diffuse Galaxy Spectroscopic Properties
  • Citing Article
  • May 2024

Monthly Notices of the Royal Astronomical Society

... First thought to mainly populate dense clusters (e.g., van Dokkum et al. 2015;Yagi et al. 2016;Mihos et al. 2015;Venhola et al. 2017Venhola et al. , 2022Wittmann et al. 2017;Gannon et al. 2022;Janssens et al. 2019;Mancera Piña et al. 2019a;Iodice et al. 2023;Marleau et al. 2024a), UDGs are now found in all environments, including the field (e.g., Yagi et al. 2016; properties include having disproportionately large numbers of globular clusters (GCs) for their stellar masses (see e.g., Forbes et al. 2020), in some rare cases hosting unusually overluminous GCs (van Dokkum et al. 2018, unusual dark matter (DM) content (both DM-dominated and DM-depleted, e.g., van Dokkum et al. 2018van Dokkum et al. , 2019Shen et al. 2021;Danieli et al. 2019;Mancera Piña et al. 2019a,b, 2022Forbes & Gannon 2024;Romanowsky et al. 2024, Tang et al. subm, Buzzo et al. in prep.), amongst others. More recently, some of these unusual properties have also been found in other low-surface brightness (LSB) galaxies that do not meet the UDG criteria (e.g., Toloba et al. 2023;Forbes & Gannon 2024;Gannon et al. 2024). ...

Analysis of galaxies at the extremes: a kinematic analysis of the Virgo cluster dwarfs VCC 9 and VCC 1448 using the Keck cosmic web imager
  • Citing Article
  • May 2024

Monthly Notices of the Royal Astronomical Society

... Goudfrooij et al. 2001a;Sharina et al. 2006;Chomiuk et al. 2008;Martocchia et al. 2018;Sesto et al. 2018), though such systems still contain a significant old GC population (e.g., Goudfrooij et al. 2001b, for NGC 1316, and only lower-mass galaxies like the Magellanic Clouds may host mostly younger GCs (e.g., Parisi et al. 2014). Such younger GCs have been shown to correlate with wet merger events both from observations and simulations (Valenzuela et al. 2024). ...

Galaxy archaeology for wet mergers: Globular cluster age distributions in the Milky Way and nearby galaxies

Astronomy and Astrophysics

... Simulations predict up to an order of magnitude loss in stellar mass (e.g. Pfeffer et al. 2024), representing a trajectory in the age-mass plane that could naturally evolve the oldest Relic clusters to the present-day GC population. Given their high masses, it is therefore logical to speculate that the GCs in the Relic will survive evaporation driven by 2-body relaxation for the age of the universe. ...

Origin of the correlation between stellar kinematics and globular cluster system richness in ultra-diffuse galaxies
  • Citing Article
  • March 2024

Monthly Notices of the Royal Astronomical Society

... However, we cannot distinguish between UV flux from the filament and UV flux from UDG 32 due to the large full-width half maximum of the GALEX images (∼ 5 ′′ ) and none of the best-fit models can reproduce the large observed UV fluxes. Figure 4 shows the stellar population properties of UDG 32 in comparison to those derived from other UDGs via spectroscopy , and references therein) and SED fitting (Buzzo et al. 2024). UDG 32 is more metal-rich than other UDGs in the Hydra I cluster (Doll et al., in prep.), and both field and cluster UDGs from the literature. ...

Constraining the stellar populations of ultra-diffuse galaxies in the MATLAS survey using spectral energy distribution fitting
  • Citing Article
  • February 2024

Monthly Notices of the Royal Astronomical Society