Physical Sciences and Mathematics | Open Access Articles

The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean Brodie, Benjamin Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter Van Dokkum

Faculty Publications

We present observational constraints on the stellar populations of two ultra-diffuse galaxies (UDGs) using optical through near-infrared (NIR) spectral energy distribution (SED) fitting. Our analysis is enabled by new Spitzer-IRAC 3.6 and 4.5 μm imaging, archival optical imaging, and the prospectorfully Bayesian SED fitting framework. Our sample contains one field UDG (DGSAT I), one Virgo cluster UDG (VCC 1287), and one Virgo cluster dwarf elliptical for comparison (VCC 1122). We find that the optical–NIR colors of the three galaxies are significantly different from each other. We infer that VCC 1287 has an old (7.7 Gyr) and surprisingly metal-poor …

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Detection Of Supermassive Black Holes In Two Virgo Ultracompact Dwarf Galaxies, Christopher Ahn, Anil Seth, Mark Den Brok, Jay Strader, Holger Baumgardt, Remco Van Den Bosch, Igor Chilingarian, Matthias Frank, Michael Hilker, Richard Mcdermid, Steffen Mieske, Aaron Romanowsky, Lee Spitler, Jean Brodie, Nadine Neumayer, Jonelle Walsh

Faculty Publications

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Ultra-Diffuse And Ultra-Compact Galaxies In The Frontier Fields Cluster Abell 2744, Steven Janssens, Roberto Abraham, Jean Brodie, Duncan Forbes, Aaron Romanowsky, Pieter Van Dokkum

Faculty Publications

We report the discovery of a large population of ultra-diffuse galaxies (UDGs) in the massive galaxy cluster Abell 2744 (z = 0.308) as observed by the Hubble Frontier Fields program. Since this cluster is ~5 times more massive than Coma, our observations allow us to extend 0.7 dex beyond the high-mass end of the relationship between UDG abundance and cluster mass reported by van der Burg et al. Using the same selection criteria as van der Burg et al., A2744 hosts an estimated 1961 ± 577 UDGs, 10 times the number in Coma. As noted by Lee & Jang, A2744 …

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Discovery Of An Ultra-Diffuse Galaxy In The Pisces-Perseus Supercluster, David Martínez-Delgado, Ronald Läsker, Margarita Sharina, Elisa Toloba, Jürgen Fliri, Rachael Beaton, David Valls-Gabaud, Igor Karachentsev, Taylor Chonis, Eva Grebel, Duncan Forbes, Aaron Romanowsky, J. Gallego-Laborda, Karel Teuwen, M. Gómez-Flechoso, Jie Wang, Puragra Guhathakurta, Serafim Kaisin, Nhung Ho

Faculty Publications

We report the discovery of DGSAT I, an ultra-diffuse, quenched galaxy located 10fdg4 in projection from the Andromeda galaxy (M31). This low-surface brightness galaxy (μV = 24.8 mag arcsec−2), found with a small amateur telescope, appears unresolved in sub-arcsecond archival Subaru/Suprime-Cam images, and hence has been missed by optical surveys relying on resolved star counts, in spite of its relatively large effective radius (Re(V) = 12'') and proximity (15') to the well-known dwarf spheroidal galaxy And II. Its red color (V − I = 1.0), shallow Sérsic index (nV = 0.68), and the absence of detectable Hα emission are typical …

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Faculty Publications

Faculty Publications

Ultra-Diffuse And Ultra-Compact Galaxies In The Frontier Fields Cluster Abell 2744, Steven Janssens, Roberto Abraham, Jean Brodie, Duncan Forbes, Aaron Romanowsky, Pieter Van Dokkum

Faculty Publications

Faculty Publications