Related papers: Hobby-Eberly Telescope Observations of the Dark Ha…
Modern Galactic surveys have revealed an ancient merger that dominates the stellar halo of our Galaxy (\textit{Gaia}-Sausage-Enceladus, GSE). Using chemical abundances and kinematics from the H3 Survey, we identify 5559 halo stars from this…
We examine the amplitude of the rotation velocity that can be attributed to the dark matter halos of disk galaxies, focusing on well measured intermediate radii. The data for 60 galaxies spanning a large range of mass and Hubble types,…
We present the first clear evidence for an extended dark matter halo in the Draco dwarf spheroidal galaxy based on a sample of new radial velocities for 159 giant stars out to large projected radii. Using a two parameter family of halo…
NGC 2915 is a nearby blue compact dwarf with the HI properties of a late-type spiral. Its large, rotating HI disk (extending out to R ~ 22 B-band scale lengths) and apparent lack of stars in the outer HI disk make it a useful candidate for…
The kinematics of the stellar halo hold important clues to the assembly history and mass distribution of the Galaxy. In this study, we map the kinematics of stars across the Galactic halo with the H3 Survey. We find a complex distribution…
We present a study of the dark and luminous matter in the isolated elliptical galaxy NGC720, based on deep X-ray observations made with Chandra and Suzaku. The gas is reliably measured to ~R2500, allowing us to place good constraints on the…
Shape estimates that quantify the halo anisotropic mass distribution are valuable parameters that provide information on their assembly process and evolution. Measurements of the mean shapes for a sample of cluster-sized halos can be used…
We investigate the dark matter density profile of the massive elliptical galaxy, NGC 1407, by constructing spherically symmetric Jeans models of its field star and globular cluster systems. Two major challenges in such models are the…
New observations of the edge-on galaxy NGC 891, at 1.15 and 2 mm obtained with the IRAM 30-m telescope and the NIKA2 camera, within the framework of the IMEGIN (Interpreting the Millimetre Emission of Galaxies with IRAM and NIKA2) Large…
We present a study of the HI distribution and dynamics of the nearby spiral galaxy NGC5055 based on observations with the Westerbork Synthesis Radio Telescope. The gaseous disk of NGC5055 extends out to about 40 kpc, equal to 3.5 R_25, and…
The distributions of size and luminosity for star-forming regions in the nearby spiral galaxy NGC 628 are studied over a wide range of scales using progressively blurred versions of an image from the Hubble Space Telescope Advanced Camera…
Modeling the Milky Way stellar halo requires well-determined density and velocity anisotropy profiles. However, it has been challenging to gather a large sample of stars with six-dimensional data that extend beyond 40 kpc to map the outer…
The spin, $\lambda$, of dark matter (DM) halos in cosmological simulations follows a log normal distribution and has little correlation with galaxy observables. As such, there is currently no way to infer the $\lambda$ parameter of…
A grand rotation curve of the Milky Way Galaxy is constructed, which covers a wide range of radius from the Galactic Center to ~1 Mpc, and is deconvolved into bulge, disk and halo components by least-squares fitting. We determined the scale…
We study the shapes of galaxy dark matter haloes by measuring the anisotropy of the weak gravitational lensing signal around galaxies in the second Red-sequence Cluster Survey (RCS2). We determine the average shear anisotropy within the…
We study the density profile and shape of the Galactic halo using deep multicolour images from the MENeaCS and CCCP projects, over 33 fields selected to avoid overlap with the Galactic plane. Using multicolour selection and PSF…
Constraints on dark matter halo masses from weak gravitational lensing can be improved significantly by using additional information about the morphology of their density distribution, leading to tighter cosmological constraints derived…
The non-circular streaming motions in barred galaxies are sensitive to the mass of the bar and can be used to lift the degeneracy between disk and dark matter halo encountered when fitting axisymmetric rotation curves of disk galaxies. In…
Current theories of galaxy formation predict that spiral galaxies are embedded in a reservoir of hot gas. This gas is able to cool onto the galaxy replenishing cold gas that is consumed by star formation. Estimates of the X-ray luminosity…
Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…