Related papers: The Distance to M51
The Andromeda Galaxy is the closest spiral galaxy to us and has been the subject of numerous studies. It harbors a massive dark matter (DM) halo which may span up to ~600 kpc across and comprises ~90% of the galaxy's total mass. This halo…
We consider seven distant galaxies with clearly evident spiral structure from HST images. Three of these were chosen from Vogt et al. (1996) (VFP) and have measured rotational velocities. Five were chosen from the Medium Deep Survey and are…
The galaxy distributions along the line-of-sight are significantly contaminated by the uncertainty on redshift measurements obtained through multiband photometry, which makes it difficult to get cosmic distance information measured from…
We present for the first time infrared observations of the nearby highly obscured galaxy Dwingeloo 1 (Dw1), including deep H-band imaging covering a total of 4.9x4.9 arcmin, together with J and Ks imaging of the central 2.5x2.5 arcmin. We…
Quickly growing computing facilities and an increasing number of extragalactic observations encourage the application of data-driven approaches to uncover hidden relations from astronomical data. In this work we raise the problem of…
We present Surface Brightness Fluctuation distances of nine early-type dwarf galaxies and the S0 galaxy NGC 4150 in the Local Volume based on deep B- and R-band CCD images obtained with the 2.56 metre Nordic Optical Telescope. Typically,…
We present deep optical observations of the gravitational lens system CLASS B0218+357, from which we derive an estimate of the Hubble constant. Extensive radio observations have reduced the degeneracies between Hubble's constant and the…
We have obtained Johnson V and Gunn i photometry for a large number of Local Group galaxies using the Isaac Newton Telescope Wide Field Camera (INT WFC). The majority of these galaxies are members of the M31 subgroup and the observations…
During the last century many observations have been made to peep into the dark matter in the universe and many astonishing behaviors of Galaxy clusters have been found which do not fit to any theories formulated before. However, Optical…
The most powerful tool for measuring distances within our Galaxy is the annual parallax. We carried out phase-referencing VLBI observations of H$_{2}$O masers in the star forming region W3(OH) with respect to the extragalactic continuum…
The distance-redshift relation plays a fundamental role in constraining cosmological models. In this paper, we show that measurements of positions and time delays of strongly lensed images of a background galaxy, as well as those of the…
This work investigates the use of a well-known empirical correlation between the velocity dispersion, metallicity, and luminosity in H beta of nearby HII galaxies to measure the distances to HII-like starburst galaxies at high redshifts.…
Distances of galaxies in the Hubble Space Telescope Key Project are based on the Cepheid period-luminosity relation. An alternative basis is the tip of the red giant branch. Using archival HST data, we calibrate the infrared Tully-Fisher…
We obtain a robust, non-parametric, estimate of the Hubble constant from galaxy linear diameters calibrated using HST Cepheid distances. Our method is independent of the parametric form of the diameter function and the spatial distribution…
We report new astrometric and spectroscopic observations of the star S2 orbiting the massive black hole in the Galactic Center, which were taken at the ESO VLT with the adaptive optics assisted, near-IR camera NAOS/CONICA and the near-IR…
The Local Group galaxies constitute a fundamental step in the definition of cosmic distance scale. Therefore, obtaining accurate distance determinations to the galaxies in the Local Group, and notably to the Andromeda Galaxy (M31), is…
Using the Hubble Space Telescope, we have resolved individual red-giant branch stars in the halos of eight nearby spiral galaxies. The fields lie at projected distances between 2 and 13 kpc along the galaxies' minor axes. The data set…
M31, our closest neighboring galaxy, is a stepping stone to studies of stellar evolution, star formation, galaxy evolution, and cosmology. However, due to the difficulties of performing photometry in such crowded fields and the lack of wide…
Dwarf satellite galaxies are a key probe of dark matter and of galaxy formation on small scales and of the dark matter halo masses of their central galaxies. They have very low surface brightness, which makes it difficult to identify and…
We study the prospects of using the low-redshift and high-redshift black hole shadows as new cosmological standard rulers for measuring cosmological parameters. We show that, using the low-redshift observation of the black hole shadow of…