Related papers: Statistical analysis of bound companions in the Co…
We find evidence for accelerated evolution in compact group galaxies from the distribution in mid-infrared colorspace of 42 galaxies from 12 Hickson Compact Groups (HCGs) compared to the the distributions of several other samples including…
(ABRIDGED) We use high resolution (~0.1") F814W ACS images from the HST ACS Treasury survey of the Coma cluster at z~0.02 to study bars in massive disk galaxies (S0s), and in dwarf galaxies in the Coma core. Our study helps constrain the…
We report the results of a systematic photometric survey of the peripheral regions of a sample of fourteen globular clusters in the outer halo of the Milky Way at distances d_GC>25 kpc from the Galactic centre. The survey is aimed at…
JWST has revealed an overabundance of apparent (`Coma'-like) cluster progenitors at $z>5$ that is $\sim$ two (300) times in excess of, and in $2.3\sigma$ ($4\sigma$) tension with, the number density of such objects at present day and…
I review the progress in research on intracluster planetary nebulae over the last five years. Hundreds more intracluster planetary nebulae have been detected in the nearby Virgo and Fornax galaxy clusters, searches of several galaxy groups…
We use deep high resolution \textit{HST/ACS} imaging of two fields in the core of the Coma cluster to investigate the occurrence of nuclear star clusters (NSCs) in quiescent dwarf galaxies as faint as $M_{I} = -10$ mag. We employ a…
We present simulated J- and K-band observations of stars in the Virgo and Coma clusters of galaxies using the proposed Next Generation Space Telescope with a Near-Infrared Camera, and discuss some of the science results that might be…
We employ spectroscopic and photometric data from SDSS DR7, in a 500 sq degree region, to understand the evolution of dwarf (~M*+2<M_z<M*+4) galaxies in the Coma supercluster (z=0.023). We show that in the Coma supercluster, the red dwarfs…
Only a handful of gas giant planets orbiting white dwarfs are known. It remains unclear whether this paucity reflects observational challenges or the consequences of stellar evolution. We aim to carry out population synthesis of substellar…
We explore the variation in stellar population ages for Coma cluster galaxies as a function of projected cluster-centric distance, using a sample of 362 red-sequence galaxies with high signal-to-noise spectroscopy. The sample spans a wide…
We describe the results and the current status of our program to search for intracluster planetary nebulae (ICPNe) in the Virgo and the Coma clusters of galaxies. For the Virgo cluster, ICPNe candidates were detected with narrow band…
Intracluster stellar populations are a natural result of tidal interactions in galaxy clusters. Measuring these populations is difficult, but important for understanding the assembly of the most massive galaxies. The Coma cluster is one of…
We present a homogeneous catalog of 275 large (effective radius $\gtrsim$ 5.3 arcsec) ultra-diffuse galaxy (UDG) candidates lying within an $\approx$ 290 square degree region surrounding the Coma cluster. The catalog results from our…
Direct imaging has led to the discovery of several giant planet and brown dwarf companions. These imaged companions populate a mass, separation and age domain (mass>1MJup, orbits>5AU, age<1Gyr) quite distinct from the one occupied by…
We have used ISO to observe at 12$\mu$m seven E+A galaxies plus an additional emission line galaxy, all in the Coma cluster. E+A galaxies lacking narrow emission lines have 2.2$\mu$m to 12$\mu$m flux density ratios or limits similar to old…
Ultra-diffuse galaxies (UDGs) are spatially extended, low surface brightness stellar systems with regular elliptical-like morphology found in a wide range of environments. Studies of the internal dynamics and dark matter content of UDGs…
We summarize here the first results of a new spectroscopic survey of galaxies in the Coma cluster with -20.5 < M_B < -14. Differences between the last epoch of star formation (SF) activity in S0 and elliptical galaxies are discussed.…
We present preliminary results from our long-baseline interferometry (LBI) survey to constrain the multiplicity properties of intermediate-mass A-type stars within 80pc. Previous multiplicity studies of nearby stars exhibit orbital…
Ultra diffuse galaxies (UDGs) reveal extreme properties. Here we compile the largest study to date of 85 globular cluster (GC) systems around UDGs in the Coma cluster, using new deep ground-based imaging of the known UDGs and existing…
Dark matter clusters on all scales, therefore it is expected that even substructure should host its own substructure. Using the Extragalactic Distance Database, we searched for dwarf galaxy satellites of dwarf galaxies, i.e.…