Related papers: Measuring the Sun's Motion with Stellar Streams
We propose a versatile and accurate method to estimate the halo mass and concentration from the kinematics of satellite galaxies. We construct the 6D phase-space distribution function of satellites from a cosmological simulation based on…
We determine the total dynamical density in the solar neighbourhood using the Tycho-Gaia Astrometric Solution (TGAS) catalogue. Astrometric measurements of proper motion and parallax of stars inform us of both the stellar number density…
We propose a method to determine the galactic constants R_0 (distance to the Galactic Center) and V_0 (rotation velocity of the Sun) from measurements of distances, radial velocities and proper motions of objects near the solar circle. This…
We present methods and preliminary results of a relatively novel search for nearby stars. The method relies on photometric distance estimates as its primary search criterion, thus distinguishing itself from proper motion-based searches that…
We introduce here in the current research the revisiting of approach to the dynamics of Sun center relative to barycenter of Solar system by using self-resulting photo-gravitational force of the Sun as the main reason of such motion. In…
A high-resolution N-body simulation suggests that stellar streams in the discs of barred galaxies are common and strongly time-dependent. The velocity distribution of stars in the Solar neighbourhood betray many such streams, including a…
We assess the practicality of computing the distance to stellar streams in our Galaxy, using the method of Galactic parallax suggested by Eyre & Binney (2009). We find that the uncertainty in Galactic parallax is dependent upon the specific…
The stellar haloes of galaxies can currently be studied either through observations of resolved halo stars or through surface photometry. Curiously, the two methods appear to give conflicting results, as a number of surface photometry…
Flat rotation curves v(r) are naturally explained by elongated (prolate) Dark Matter (DM) distributions, and we have provided competitive fits to the SPARC database. To further probe the geometry of the halo one needs out-of-plane…
We combine Gaia data release 1 astrometry with Sloan Digital Sky Survey (SDSS) images taken some ~10-15 years earlier, to measure proper motions of stars in the halo of our Galaxy. The SDSS-Gaia proper motions have typical statistical…
The measurement of Doppler velocities in spectroscopic solar observations requires a reference for the local frame of rest. The rotational and radial velocities of the Earth and the rotation of the Sun introduce velocity offsets in the…
We propose an extension of the GC3 streamer finding method of Johnston et al. 1996 that can be applied to the future Gaia database. The original method looks for streamers along great circles in the sky, our extension adds the kinematical…
We develop a new method StarGO (Stars' Galactic Origin) to identify the galactic origins of halo stars using their kinematics. Our method is based on self-organizing map (SOM), which is one of the most popular unsupervised learning…
Dynamically cold stellar streams from tidally dissolved globular clusters (GCs) serve as excellent tools to measure the Galactic mass distribution and show promise to probe the nature of dark matter. For successful application of these…
A new method is proposed for directly measuring the expansion rate of the universe through very precise measurement of the fluence of extremely stable sources. The method is based on the definition of the luminosity distance and its change…
A direct observation of the spiral structure of the Galaxy is hindered by our position in the middle of the Galactic plane. We propose a method based on the analysis of the birthplaces of high Galactic latitude runaway stars to map the…
The dark matter subhalos orbiting in a galactic halo perturb the orbits of stars in thin stellar streams. Over time the random velocities in the streams develop non-Gaussian wings. The rate of velocity increase is approximately a random…
When a massive object crosses a star stream velocity changes are induced both along and transverse to the stream which can lead to the development of a visible gap. For a stream narrow relative to its orbital radius the time of stream…
There is a desire to observe the sun's poles to further deepen our understanding of solar activity. However, because of the large speeds needed to perform out-of-ecliptic plane maneuvers, chemical and electric rocket propulsion mechanisms…
Measuring the density profile of dark matter in the Solar neighborhood has important implications for both dark matter theory and experiment. In this work, we apply autoregressive flows to stars from a realistic simulation of a Milky…