Browsing by Author "Sales, Laura V."

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    An evolutionary continuum from nucleated dwarf galaxies to star clusters
    (2023) Wang, Kaixiang; Peng, Eric W.; Liu, Chengze; Mihos, J. Christopher; Cote, Patrick; Ferrarese, Laura; Taylor, Matthew A.; Blakeslee, John P.; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Guhathakurta, Puragra; Gwyn, Stephen; Ko, Youkyung; Lancon, Ariane; Lim, Sungsoon; Macarthur, Lauren A.; Puzia, Thomas; Roediger, Joel; Sales, Laura V.; Sanchez-Janssen, Ruben; Spengler, Chelsea; Toloba, Elisa; Zhang, Hongxin; Zhu, Mingcheng
    Systematic studies1-4 have revealed hundreds of ultra-compact dwarf galaxies (UCDs5) in the nearby Universe. With half-light radii rh of approximately 10-100 parsecs and stellar masses M* approximate to 106-108 solar masses, UCDs are among the densest known stellar systems6. Although similar in appearance to massive globular clusters7, the detection of extended stellar envelopes4,8,9, complex star formation histories10, elevated mass-to-light ratio11,12 and supermassive black holes13-16 suggest that some UCDs are remnant nuclear star clusters17 of tidally stripped dwarf galaxies18,19, or even ancient compact galaxies20. However, only a few objects have been found in the transient stage of tidal stripping21,22, and this assumed evolutionary path19 has never been fully traced by observations. Here we show that 106 galaxies in the Virgo cluster have morphologies that are intermediate between normal, nucleated dwarf galaxies and single-component UCDs, revealing a continuum that fully maps this morphological transition and fills the 'size gap' between star clusters and galaxies. Their spatial distribution and redder colour are also consistent with stripped satellite galaxies on their first few pericentric passages around massive galaxies23. The 'ultra-diffuse' tidal features around several of these galaxies directly show how UCDs are forming through tidal stripping and that this evolutionary path can include an early phase as a nucleated ultra-diffuse galaxy24,25. These UCDs represent substantial visible fossil remnants of ancient dwarf galaxies in galaxy clusters, and more low-mass remnants probably remain to be found.
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    Dark Matter in Ultra-diffuse Galaxies in the Virgo Cluster from Their Globular Cluster Populations
    (2018) Toloba, Elisa; Lim, Sungsoon; Peng, Eric; Sales, Laura V.; Guhathakurta, Puragra; Mihos, J. Christopher; Cote, Patrick; Boselli, Alessandro; Cuillandre, Jean-Charles; Ferrarese, Laura; Gwyn, Stephen; Lancon, Ariane; Munoz, Roberto; Puzia, Thomas H.
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    The Next Generation Virgo Cluster Survey (NGVS). XXVII. The Size and Structure of Globular Cluster Systems and Their Connection to Dark Matter Halos
    (2024) Lim, Sungsoon; Peng, Eric W.; Cote, Patrick; Ferrarese, Laura; Roediger, Joel C.; Liu, Chengze; Spengler, Chelsea; Sola, Elisabeth; Duc, Pierre-Alain; Sales, Laura V.; Blakeslee, John P.; Cuillandre, Jean-Charles; Durrell, Patrick R.; Emsellem, Eric; Gwyn, Stephen D. J.; Lancon, Ariane; Marleau, Francine R.; Mihos, J. Christopher; Mueller, Oliver; Puzia, Thomas H.; Sanchez-Janssen, Ruben
    We study the size and structure of globular cluster (GC) systems of 118 early-type galaxies from the NGVS, MATLAS, and ACSVCS surveys. Fitting S & eacute;rsic profiles, we investigate the relationship between effective radii of GC systems (R-e,R-gc) and galaxy properties. GC systems are 2-4 times more extended than host galaxies across the entire stellar mass range of our sample (10(8.3)M(circle dot) < M-* < 10(11.6)M(circle dot)). The relationship between R-e,R-gc and galaxy stellar mass exhibits a characteristic "knee" at a stellar mass of M-p similar or equal to 10(10.8), similar to the galaxy R-e-stellar mass relationship. We present a new characterization of the traditional blue and red GC color subpopulations, describing them with respect to host galaxy color (Delta(gi)): GCs with similar colors to their hosts have a "red" Delta(gi), and those significantly bluer GCs have a "blue" Delta(gi). The GC populations with red Delta(gi), even in dwarf galaxies, are twice as extended as the stars, suggesting that formation or survival mechanisms favor the outer regions. We find a tight correlation between R-e,R-gc and the total number of GCs, with intrinsic scatter less than or similar to 0.1 dex spanning two and three orders of magnitude in size and number, respectively. This holds for both red and blue subpopulations, albeit with different slopes. Assuming that N-GC,N-Total correlates with M-200, we find that the red GC systems have effective radii of roughly 1%-5% R-200, while the blue GC systems in massive galaxies can have sizes as large as similar to 10% R-200. Environmental dependence on R-e,R-gc is also found, with lower-density environments exhibiting more extended GC systems at fixed mass.