相关论文: Simulations of cluster ultra-diffuse galaxies in M…

Strong gravitational lensing observations can test structure formation models by constraining the masses and concentrations of subhaloes in massive galaxy clusters. Recent work has concluded that cluster subhaloes are more abundant and/or…

In the context of theories of gravity modified to account for the observed dynamics of galactic systems without the need to invoke the existence of dark matter, a prediction often appears regarding low acceleration systems: wherever $a$…

We have obtained FUV spectra of two clusters of galaxies with FUSE, the Far Ultraviolet Spectroscopic Explorer. The Coma cluster was observed for a total of 28.6 ksec, the Virgo cluster for 10.9 ksec. Neither spectrum shows significant O VI…

We present Keck/DEIMOS spectroscopy of the first complete sample of ultra-diffuse galaxies (UDGs) in the Virgo cluster. We select all UDGs in Virgo that contain at least 10 globular cluster (GC) candidates and are more than $2.5\sigma$…

(abridged) Context. Gravitational fields at the outskirts of early-type galaxies (ETGs) are difficult to constrain observationally. It thus remains poorly explored how well the LCDM and MOND hypotheses agree with ETGs. Aims. This led us to…

The virial masses of ultra-diffuse galaxies (UDGs) have been estimated using the kinematics and abundance of their globular cluster populations, leading to disparate results. Some studies conclude that UDGs reside in massive dark matter…

In order to help facilitate the future study of ultra-diffuse galaxies (UDGs) we compile a catalogue of their spectroscopic properties. Using it, we investigate some of the biases inherent in the current UDG sample that have been targeted…

We use a one dimensional hydrodynamical code to study the evolution of spherically symmetric perturbations in the framework of Modified Newtonian Dynamics (MOND). The code evolves spherical gaseous shells in an expanding Universe by…

Galaxy clusters are known to induce gas loss in infalling galaxies due to the ram pressure exerted by the intracluster medium over their gas content. In this paper, we investigate this process through a set of simulations of Milky Way like…

The recent discovery of the most extended ultra-diffuse galaxy (UDG), Nube, has raised yet another question about the validity of the cold dark matter (CDM) model. The studies using cosmological and zoom-in simulations, which assume CDM,…

Due to their low surface brightness, dwarf galaxies are particularly susceptible to tidal forces. The expected degree of disturbance depends on the assumed gravity law and whether they have a dominant dark halo. This makes dwarf galaxies…

After the stars of a new, embedded star cluster have formed they blow the remaining gas out of the cluster. Especially winds of massive stars and definitely the on-set of the first supernovae can remove the residual gas from a cluster. This…

We present neutral hydrogen (HI) observations using the Robert C. Byrd Green Bank Telescope (GBT) of 70 optically-detected UDG candidates in the Coma region from the Systematically Measuring Ultra-Diffuse Galaxies survey (SMUDGes). We…

The works in this portfolio test the hypothesis that it is not possible to extrapolate the Newtonian inverse square law of gravity from Solar System to galaxy scales. In particular, I look into various tests of Modified Newtonian Dynamics…

It has been suggested that ultra-compact dwarf (UCD) galaxies are the "threshed'" remains of larger galaxies. Simulations have revealed that extensive tidal-stripping may pare a galaxy back to its tightly-bound, compact nuclear star…

We present intermediate-resolution spectroscopic data for a set of dwarf and giant galaxies in the Coma Cluster, with -20.6 < M_R < -15.7. The photometric and kinematic properties of the brighter galaxies can be cast in terms of parameters…

In addition to occupying the extreme, diffuse tail of the dwarf galaxy population, Ultra-Diffuse Galaxies (UDGs) are themselves a key laboratory in which to study star formation in extreme low-density environments. In the second paper of…

In this paper we investigate the velocity dispersion profiles of clusters of galaxies for seven cosmological models. One model is the SCDM model, and the others are six low-density models with the density parameter $\Omega=0.1$, 0.2 or 0.3…

We determine the mean velocity dispersion of six Galactic outer halo globular clusters, AM 1, Eridanus, Pal 3, Pal 4, Pal 15, and Arp 2 in the weak acceleration regime to test classical vs. modified Newtonian dynamics (MOND). Owing to the…

The detection of excess of soft X-ray or Extreme Ultraviolet (EUV) radiation, above the thermal contribution from the hot intracluster medium (ICM), has been a controversial subject ever since the initial discovery of this phenomenon. We…