Related papers: A Closer Look at an Unusual Ultra-Diffuse Galaxy
Using the Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) we performed an untargeted search for H I-bearing ultra-diffuse galaxies (UDGs). We identified a core sample of 10 UDGs defined by $\mu_{g,0}\ge24$ mag arcsec$^{-2}$ and…
There is increasing observational evidence for a failed galaxy formation pathway for some ultradiffuse galaxies (UDGs) at low redshift however they currently lack simulated counterparts. We attempt to identify dark matter halos at high…
Recently van Dokkum et al. (2018b) reported that the galaxy NGC 1052-DF2 (DF2) lacks dark matter if located at $20$ Mpc from Earth. In contrast, DF2 is a dark-matter-dominated dwarf galaxy with a normal globular cluster population if it has…
(Abridged) We use the largest set of globular cluster velocities obtained so far of any elliptical galaxy to revise and extend the previous investigations of the dynamics of NGC 1399, the central dominant galaxy of the nearby Fornax cluster…
We present dynamical status of the Galactic globular cluster NGC 6656 using spatial distribution of Blue Straggler Stars (BSSs). A combination of multi-wavelength high-resolution space and ground-based data are used to cover a large cluster…
Ultracompact dwarf galaxies (UCDs) are among the densest stellar systems in the universe. These systems have masses up to 200 million solar masses, but half light radii of just 3-50 parsecs. Dynamical mass estimates show that many UCDs are…
NGC3201 is a globular cluster (GC) which shows very peculiar kinematic characteristics including an extreme radial velocity and a highly retrograde orbit, strongly suggesting an extraGalactic origin. Our aims are to study NGC3201 in the…
We present B- and R-band imaging and photometry, H-alpha narrow-band imaging, NIR H-band imaging, and HI 21-cm spectroscopy of the nearby Sd spiral galaxy UGC7321. UGC7321 exhibits a remarkably thin stellar disk with no bulge component. The…
We analyze the nuclear stellar dynamics of the SB0 galaxy NGC 1023, utilizing observational data both from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope and from the ground. The stellar kinematics measured from…
We present high-resolution echelle spectroscopy, obtained with the UVES spectrograph on ESO/VLT, of two luminous star clusters in the metal-poor blue compact galaxy ESO 338-IG04 at a distance of 37.5 Mpc. Cross-correlating with template…
We report a detailed investigation of the bulk motions of the nearby Galactic stellar disk, based on three samples selected from the LSS-GAC DR2: a global sample containing 0.57 million FGK dwarfs out to $\sim$ 2 kpc, a local subset of the…
MOND reduces greatly the mass discrepancy in clusters of galaxies, but does leave a consistent global discrepancy of about a factor of two. It has been proposed, within the minimalist and purist MOND, that clusters harbor some indigenous,…
Using Jeans modelling, we calculate the velocity dispersion profile of the ultra-diffuse galaxy (UDG) Dragonfly 44 in MOND. For the nominal mass-to-light ratio from the literature and an isotropic profile, the agreement with the data is…
WFPC2 images obtained with the Hubble Space telescope 4.16 years apart have allowed us to measure the proper motion of the metal rich globular cluster NGC 6553 with respect to the background bulge stars. With a space velocity of (${\Pi},…
HIRES on the Keck I telescope has been used to measure the first radial velocities for stars belonging to eleven, heavily-reddened globular clusters in the direction of the inner Galaxy. The question of kinematic substructuring among the…
The velocity dispersion of the ultra diffuse galaxy NGC1052-DF2 was found to be $\sigma_{\rm gc}=7.8^{+5.2}_{-2.2} \ \mathrm{kms^{-1}}$, much lower than expected from the stellar mass -- halo mass relation and nearly identical to the…
Our 2dF Fornax Cluster Spectroscopic Survey (FCSS) and follow-up work in the Virgo Cluster have shown that the cores of both galaxy clusters contain a previously-unknown class of object, ultra-compact dwarf (UCD) galaxies. We present high…
We present a detailed dynamical analysis of the rich galaxy cluster A2744, containing a powerful diffuse radio halo.Our analysis is based on redshift data for 102 galaxies, part of them recovered from unexplored spectra in the ESO archive.…
Given the absence of directly detected dark matter (DM) as weakly interacting massive particles, there is strong interest in the possibility that DM is an ultra-light scalar field, here denoted as fuzzy DM. Ultra-diffuse galaxies, with the…
We present spectroscopic confirmation of an ultra-massive galaxy (UMG) with $\log(M_\star/M_\odot) = 10.98 \pm 0.07$ at $z_\mathrm{spec} = 4.8947$ in the Extended Groth Strip (EGS), based on deep observations of Ly$\alpha$ emission with…