Related papers: Local Group Proper Motion Dynamics
Astrophysical observations indicate that the ``Local Universe" has a relatively lower matter density ($\Omega_0$) than the predictions of the standard inflation cosmology and the large-scale motions of galaxies which provide a mean mass…
By virtue of their high galaxy space densities and their large spatial separations, clusters are efficient and accurate tracers of the large-scale density and velocity fields. Substantial progress has been made over the past decade in the…
I review current efforts to measure the mean density of dark matter near the Sun. This encodes valuable dynamical information about our Galaxy and is also of great importance for 'direct detection' dark matter experiments. I discuss…
The presence of dark matter, though well established by indirect evidence, is yet to be observed directly. Various dark matter detection experiments running for several years have yielded no positive results. In view of these negative…
We only see a small fraction of the matter in the universe, but the rest gives itself away by the impact of its gravity. The distortions from pure Hubble flow (or peculiar velocities) that this matter creates have the potential to be a…
Many of the satellites of galactic-mass systems such as the Miky Way, Andromeda and Centaurus A show evidence of coherent motions to a larger extent than most of the systems predicted by the standard cosmological model. It is an open…
Remarkable development of cosmology is benefited from the increasingly improved measurements of cosmic distances including absolute distances and relative distances. In recent years, however, the emerged cosmological tensions motivate us to…
The local density of dark matter is an important quantity. On the one hand, its value is needed for dark matter direct detection searches. On the other hand, a precise and robust determination of the local dark matter density would help us…
The Local Group Census is a narrow- and broad-band survey of all the galaxies of the Local Group above dec = -30 deg, in progress at the 2.5m Isaac Newton telescope on La Palma. We discuss here the ability of the survey to detect symbiotic…
We perform a comprehensive determination of the systemic proper motions of 74 dwarf galaxies and dwarf galaxy candidates in the Local Group based on Gaia early data release 3. The outputs of the analysis for each galaxy, including…
Properties of groups of galaxies depend sensitively on the algorithm for group selection, and even the most recent catalogs of groups built from redshift-space selection should suffer from projections and infalling galaxies. The…
With the advent of the Gaia data, the unprecedented kinematic census of great part of the Milky Way disc will allow us to characterise the local kinematic groups and new groups in different disc neighbourhoods. First, we show here that the…
Accelerations of both the solar system barycenter (SSB) and stars in the Milky Way cause a systematic observational effect on the stellar proper motions, which was first studied in the early 1990s and developed by J. Kovalevsky (aberration…
We introduce "Simulations Beyond The Local Universe" (SIBELIUS) that connect the Local Group to its cosmic environment. We show that introducing hierarchical small-scale perturbations to a density field constrained on large scales by…
There is a $\sim 150 km s^{-1}$ discrepancy between the measured motion of the Local Group of galaxies (LG) with respect to the CMB and the linear theory prediction based on the gravitational force field of the large scale structure in…
In this review I will describe a number of recent advances in extragalactic astronomy. First of all I will describe our current best estimates of the star formation history of the Universe. Then I will describe measurements of local…
The study of the kinematics of globular clusters (GCs) offers the possibility of unveiling their long term evolution and uncovering their yet unknown formation mechanism. Gaia DR2 has strongly revitalized this field and enabled the…
Images of 10 galaxies in F814W and F606W filters obtained on the Hubble Space Telescope (HST) are used to construct color-magnitude diagrams for the star population of these galaxies. The distances to the galaxies are estimated from the…
For 100 years since galaxies were found to be flying apart from each other, astronomers have been trying to determine how fast. The expansion, characterized by the Hubble constant, H0, is confused locally by peculiar velocities caused by…
The 2020s are poised to continue the past two decades of significant advances based on observations of dwarf galaxies in the nearby universe. Upcoming wide-field photometric surveys will probe substantially deeper than previous data sets,…