Browsing by Author "Duc, Pierre-Alain"

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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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    Discovery of Ram-pressure stripped gas around an Elliptical Galaxy in Abell 2670.
    (2017) Sheen, Yun-Kyeong; Treister, Ezequiel; Smith, Rory; Jaffé, Yara; Kim, Minjin; Yi, Sukyoung K.; Duc, Pierre-Alain; Nantais, Julie; Candlish, Graeme; Demarco, R.
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    New constraints on a complex relation between globular cluster colors and environment
    (2016) Powalka, Mathieu; Puzia, Thomas H.; Lançon, Ariane; Peng, Eric W.; Schönebeck, Frederik; Alamo Martínez, Karla; Ángel Ángel, Simón Andrés; Blakeslee, John P.; Côté, Patrick; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Durrell, Patrick; Ferrarese, Laura; Grebel, Eva K.; Guhathakurta, Puragra; Gwyn, S. D. J.; Kuntschner, Harald; Lim, Sungsoon; Liu, Chengze; Lyubenova, Mariya
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    The Black Hole-Galaxy Connection: Interplay between Feedback, Obscuration, and Host Galaxy Substructure
    (2022) Juneau, Stephanie; Goulding, Andy D.; Banfield, Julie; Bianchi, Stefano; Duc, Pierre-Alain; Ho, I-Ting; Dopita, Michael A.; Scharwaechter, Julia; Bauer, Franz E.; Groves, Brent; Alexander, David M.; Davies, Rebecca L.; Elbaz, David; Freeland, Emily; Hampton, Elise; Kewley, Lisa J.; Nikutta, Robert; Shastri, Prajval; Shu, Xinwen; Vogt, Frederic P. A.; Wang, Tao; Wong, O. Ivy; Woo, Jong-Hak
    There is growing evidence for physical influence between supermassive black holes and their host galaxies. We present a case study of the nearby galaxy NGC 7582, for which we find evidence that galactic substructure plays an important role in affecting the collimation of ionized outflows as well as contributing to the heavy active galactic nucleus (AGN) obscuration. This result contrasts with a simple, small-scale AGN torus model, according to which AGN-wind collimation may take place inside the torus itself, at subparsec scales. Using 3D spectroscopy with the Multi Unit Spectroscopic Explorer instrument, we probe the kinematics of the stellar and ionized gas components as well as the ionization state of the gas from a combination of emission-line ratios. We report for the first time a kinematically distinct core (KDC) in NGC 7582, on a scale of similar to 600 pc. This KDC coincides spatially with dust lanes and starbursting complexes previously observed. We interpret it as a circumnuclear ring of stars and dusty, gas-rich material. We obtain a clear view of the outflowing cones over kiloparsec scales and demonstrate that they are predominantly photoionized by the central engine. We detect the back cone (behind the galaxy) and confirm previous results of a large nuclear obscuration of both the stellar continuum and H ii regions. While we tentatively associate the presence of the KDC with a large-scale bar and/or a minor galaxy merger, we stress the importance of gaining a better understanding of the role of galaxy substructure in controlling the fueling, feedback, and obscuration of AGNs.
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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.
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    The Next Generation Virgo Cluster Survey (NGVS). XXXI. The Kinematics of Intracluster Globular Clusters in the Core of the Virgo Cluster
    (2018) Longobardi, Alessia; Peng, Eric W.; Cote, Patrick; Mihos, J. Christopher; Ferrarese, Laura; Puzia, Thomas H.; Lancon, Ariane; Zhang, Hong-Xin; Munoz, Roberto P.; Blakeslee, John P.; Guhathakurta, Puragra; Durrell, Patrick R.; Sanchez-Janssen, Ruben; Toloba, Elisa; Jordán Colzani, Andrés Cristóbal; Eyheramendy Duerr, Susana; Cuillandre, Jean-Charles; Gwyn, Stephen D. J.; Boselli, Alessandro; Duc, Pierre-Alain; Liu, Chengze; Alamo-Martinez, Karla; Powalka, Mathieu; Lim, Sungsoon
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    The Next Generation Virgo Cluster Survey (NGVS). XXXII. A Search for Globular Cluster Substructures in the Virgo Galaxy Cluster Core
    (2018) Powalka, Mathieu; Puzia, Thomas H.; Lancon, Ariane; Longobardi, Alessia; Peng, Eric W.; Duc, Pierre-Alain; Alamo-Martinez, Karla; Blakeslee, John P.; Cote, Patrick; Cuillandre, Jean-Charles; Durrell, Patrick; Eigenthaler, Paul; Ferrarese, Laura; Guhathakurta, Puragra; Gwyn, S. D. J.; Hudelot, Patrick; Liu, Chengze; Mei, Simona; Munoz, Roberto P.; Roediger, Joel; Sanchez-Janssen, Ruben; Toloba, Elisa; Zhang, Hongxin
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    The Next Generation Virgo Cluster Survey. XXIII. Fundamentals of Nuclear Star Clusters over Seven Decades in Galaxy Mass
    (2019) Sanchez-Janssen, Ruben; Cote, Patrick; Ferrarese, Laura; Peng, Eric W.; Roediger, Joel; Blakeslee, John P.; Emsellem, Eric; Puzia, Thomas H.; Spengler, Chelsea; Taylor, James; Alamo-Martinez, Karla A.; Boselli, Alessandro; Cantiello, Michele; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Durrell, Patrick; Gwyn, Stephen; MacArthur, Lauren A.; Lancon, Ariane; Lim, Sungsoon; Liu, Chengze; Mei, Simona; Miller, Bryan; Munoz, Roberto; Mihos, J. Christopher; Paudel, Sanjaya; Powalka, Mathieu; Toloba, Elisa
    Using deep, high-resolution optical imaging from the Next Generation Virgo Cluster Survey, we study the properties of nuclear star clusters (NSCs) in a sample of nearly 400 quiescent galaxies in the core of Virgo with stellar masses 10(5) less than or similar to M-*/M-circle dot less than or similar to 10(12). The nucleation fraction reaches a peak value f(n) approximate to 90% for M-* approximate to 10(9) M-circle dot galaxies and declines for both higher and lower masses, but nuclei populate galaxies as small as M-* approximate to 5 x 10(5) M-circle dot. Comparison with literature data for nearby groups and clusters shows that at the low-mass end nucleation is more frequent in denser environments. The NSC mass function peaks at M-NSC approximate to 7 x 10(5) M-circle dot, a factor 3-4 times larger than the turnover mass for globular clusters (GCs). We find a nonlinear relation between the stellar masses of NSCs and those of their host galaxies, with a mean nucleus-to-galaxy mass ratio that drops to M-NSC/M-* approximate to 3.6 x 10(-3) for M-* approximate to 5 x 10(9) M-circle dot galaxies. Nuclei in both more and less massive galaxies are much more prominent: M-NSC proportional to M-*(0.46) at the low-mass end, where nuclei are nearly 50% as massive as their hosts. We measure an intrinsic scatter in NSC masses at a fixed galaxy stellar mass of 0.4 dex, which we interpret as evidence that the process of NSC growth is significantly stochastic. At low galaxy masses we find a close connection between NSCs and GC systems, including very similar occupation distributions and comparable total masses. We discuss these results in the context of current dissipative and dissipationless models of NSC formation.
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    The Next Generation Virgo Cluster Survey. XXXIII. Stellar Population Gradients in the Virgo Cluster Core Globular Cluster System
    (2022) Ko, Youkyung; Peng, Eric W.; Cote, Patrick; Ferrarese, Laura; Liu, Chengze; Longobardi, Alessia; Lancon, Ariane; Munoz, Roberto P.; Puzia, Thomas H.; Alamo-Martinez, Karla A.; Sales, Laura, V; Ramos-Almendares, Felipe; Abadi, Mario G.; Lee, Myung Gyoon; Hwang, Ho Seong; Caldwell, Nelson; Blakeslee, John P.; Boselli, Alessandro; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Eyheramendy, Susana; Guhathakurta, Puragra; Gwyn, Stephen; Jordan, Andres; Lim, Sungsoon; Sanchez-Janssen, Ruben; Toloba, Elisa
    We present a study of the stellar populations of globular clusters (GCs) in the Virgo Cluster core with a homogeneous spectroscopic catalog of 692 GCs within a major-axis distance R (maj) = 840 kpc from M87. We investigate radial and azimuthal variations in the mean age, total metallicity, [Fe/H], and alpha-element abundance of blue (metal-poor) and red (metal-rich) GCs using their co-added spectra. We find that the blue GCs have a steep radial gradient in [Z/H] within R (maj) = 165 kpc, with roughly equal contributions from [Fe/H] and [alpha/Fe], and flat gradients beyond. By contrast, the red GCs show a much shallower gradient in [Z/H], which is entirely driven by [Fe/H]. We use GC-tagged Illustris simulations to demonstrate an accretion scenario where more massive satellites (with more metal- and alpha-rich GCs) sink further into the central galaxy than less massive ones, and where the gradient flattening occurs because of the low GC occupation fraction of low-mass dwarfs disrupted at larger distances. The dense environment around M87 may also cause the steep [alpha/Fe] gradient of the blue GCs, mirroring what is seen in the dwarf galaxy population. The progenitors of red GCs have a narrower mass range than those of blue GCs, which makes their gradients shallower. We also explore spatial inhomogeneity in GC abundances, finding that the red GCs to the northwest of M87 are slightly more metal-rich. Future observations of GC stellar population gradients will be useful diagnostics of halo merger histories.
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    THE. NEXT. GENERATION. VIRGO. CLUSTER. SURVEY. VII. THE. INTRINSIC. SHAPES. OF. LOW-LUMINOSITY. GALAXIES. IN. THE. CORE. OF. THE. VIRGO. CLUSTER, AND. A. COMPARISON. WITH. THE. LOCAL. GROUP
    (2016) Sánchez-Janssen, Rubén; Ferrarese, Laura; MacArthur, Lauren A.; Côté, Patrick; Blakeslee, John P.; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Durrell, Patrick; Gwyn, Stephen; Puzia, Thomas H.