Related papers: Limits on Ionized Gas in M81's Globular Clusters
We report the results from a pilot study of 10 nearby starburst and active galaxies conducted with the Taurus Tunable Filter (TTF) on the Anglo-Australian and William Herschel Telescopes. The main purpose of this imaging survey is to search…
Young star clusters with masses well in excess of 100.000 Msun have been observed not only in merger galaxies and large-scale starbursts, but also in fairly normal, undisturbed spiral and irregular galaxies. Here we present virial mass…
Empirically, the total number (or total mass) of globular clusters bound in a single galactic system correlates with the viral mass of the system. The form of this relation and its intrinsic scatter are potentially valuable constraints on…
Hot gaseous halos are predicted around all large galaxies and are critically important for our understanding of galaxy formation, but they have never been detected at distances beyond a few kpc around a spiral galaxy. We used the Chandra…
The existence of the three most massive clusters of galaxies observed so far at z>0.5 is used to constrain the mass density parameter of the universe, Omega, and the amplitude of mass fluctuations, sigma_8. We find Omega=0.2 (+0.3,-0.1),…
We investigate the molecular gas content and the excitation and fragmentation properties in the central region of the spiral galaxy Messier 81 in both the ^{12}CO(1-0) and ^{12}CO(2-1) transitions. We have recently observed the two…
(Abridged) We present fine structure and recombination lines observations of the ionized gas toward a sample of 18 sources located within 300 pc of the center of the Galaxy (GC). The fine structure lines from [NII] and [SIII] have been…
We report a survey for molecular gas in nearby powerful radio galaxies. Eight of the eighteen radio galaxies observed were detected with molecular masses in the range 10^7--10^9 Msun, similar to the same survey we performed towards 3C radio…
I present a simple phenomenological model for the observed linear scaling of the stellar mass in old globular clusters (GCs) with $z=0$ halo mass in which the stellar mass in GCs scales linearly with progenitor halo mass at $z=6$ above a…
The observed masses of the most massive stars do not surpass about 150Msun. This may either be a fundamental upper mass limit which is defined by the physics of massive stars and/or their formation, or it may simply reflect the increasing…
We use HI absorption measurements to constrain the amount of cool ($\approx 10^4$ K), photoionized gas in the circumgalactic medium (CGM) of dwarf galaxies with $M_* = 10^{6.5-9.5}~M_\odot$ in the nearby Universe ($z<0.3$). We show…
The study of outer halo globular cluster (GC) populations can give insight into galaxy merging, globular cluster accretion and the origin of GCs. We use archival Subaru Hyper Suprime-Cam (HSC) data in concert with space-based GALEX, IRAC…
Observations with the Chandra X-ray Observatory are used to examine the hot gas properties within a sample of 10 galaxy groups selected from the Galaxy And Mass Assembly survey's optical Friends-of-Friends group catalogue. Our groups have…
We present an analysis of Chandra X-ray observations of a compact group of galaxies, HCG 80 (z=0.03). The system is a spiral-only group composed of four late-type galaxies, and has a high-velocity dispersion of 309 km/s. With…
We present 12CO J=1-0 observations from the Caltech Millimeter Array of a field in the nearby spiral galaxy M81. We detect emission from three features that are the size of large giant molecular clouds (GMCs) in the Milky Way Galaxy and…
We collected radial velocities of more than 50.000 individual stars in 156 Galactic globular clusters (GGC) and matched them with HST photometry and Gaia DR2 proper motions. This allowed us to derive the GGC's mean proper motions and space…
We analyze the intracluster medium (ICM) and circumgalactic medium (CGM) in 7 X-ray detected galaxy clusters using spectra of background QSOs (HST-COS/STIS), optical spectroscopy of the cluster galaxies (MMT/Hectospec and SDSS), and X-ray…
We have collected spectra of about 2000 red giant branch (RGB) stars in 19 Galactic globular clusters (GC) using FLAMES@VLT (about 100 star with GIRAFFE and about 10 with UVES, respectively, in each GC). These observations provide an…
High mass galaxies, with halo masses $M_{200} \ge 10^{10} M_{\odot}$, reveal a remarkable near-linear relation between their globular cluster (GC) system mass and their host galaxy halo mass. Extending this relation to the mass range of…
The relation between the total mass contained in the globular clusters of a galaxy and the mass of its dark matter halo has been found observationally to be nearly linear over five decades of mass. However, the high-mass end of this…