Related papers: The Distance to the Coma Cluster from Surface Brig…
Type Ia supernovae (SNe) are the best standard candles available today in spite of an appreciable intrinsic variation of their luminosities at maximum phase, and of probably non-uniform progenitors. For an unbiased use of type Ia SNe as…
To determine the relative distances and peculiar velocities of 140 groups and clusters of galaxies at low redshifts ($z$ < 0.12), we used the fundamental plane (FP) of early-type galaxies (from the Sloan Digital Sky Survey (SDSS) data). We…
The most recent Hubble constant ($H_0)$ estimates from local methods (z << 1), $H_0=73.8\pm 2.4$ km s$^{-1}$ Mpc$^{-1}$, and the one from high redshifts $H_0=67.3\pm 1.2$ km s$^{-1}$ Mpc$^{-1}$, are discrepant at $2.4 \sigma$ confidence…
We compare two methods for deriving distances to early-type galaxies: fundamental plane (FP) and surface brightness fluctuations (SBF) distances for 170 galaxies. A third set of distances is provided by predictions derived from the density…
We present the UBVRI light curves of the Type Ia supernova SN 1998bu which appeared in the nearby galaxy M96 (NGC 3368). M96 is a spiral galaxy in the Leo I group which has a Cepheid-based distance. Our photometry allows us to calculate the…
We present wide-field spectroscopy of globular clusters around the Leo I group galaxies NGC 3379 and NGC 3384 using the FLAMES multi-fibre instrument at the VLT. We obtain accurate radial velocities for 42 globular clusters (GCs) in total,…
Four Hubble diagrams are combined to test for the linearity of the cosmic expansion field. The expansion rate, H_0, is found to decrease by ~5% out to 18000km/s. Beyond this distance the mean value of H_0 is close to the value at 10000km/s.…
The large-scale distribution of globular clusters in the central region of the Coma cluster of galaxies is derived through the analysis of Hubble Space Telescope/Advanced Camera for Surveys data. Data from three different HST observing…
The HST's WFPC2 has several advantages over ground--based observations for the study of globular cluster luminosity functions (GCLFs) and distance determination. Here we present WFPC2 data on the globular clusters associated with NGC 5846.…
We perform a series of comparisons between distance-independent photometric and spectroscopic properties used in the surface brightness fluctuations (SBF) and fundamental plane (FP) methods of early-type galaxy distance estimation. The data…
Surface brightness fluctuation (SBF) magnitudes are a powerful standard candle to measure distances to semi-resolved galaxies in the local universe, a majority of which are dwarf galaxies that have often bluer colors than bright early-type…
Taking advantage of the exceptional capabilities of ACS on board of HST, we derive Surface Brightness Fluctuation (SBF) measurements in the B and I bands from images of six elliptical galaxies with $1500 \leq cz \leq 3500$. Given the low…
The surface brightness fluctuation (SBF) technique is one of the distance measurement methods that has been applied on the low surface brightness galaxy NGC 1052-DF2 yielding a distance of about 20 Mpc implying it to be a dark matter…
There is a persistent tension of about $5\sigma-6\sigma$ between the value of the Hubble constant, as derived from the local distance ladder vs. the cosmic microwave background, signaling either unaccounted for systematics in the…
We determine the distances to 18 galaxy clusters with redshifts ranging from z~0.14 to z~0.78 from a maximum likelihood joint analysis of 30 GHz interferometric Sunyaev-Zel'dovich effect (SZE) and X-ray observations. We model the…
The correlation between the luminosities and rotation velocities of galaxies can be used to estimate distances to late-type galaxies. It is an appropriate moment to re-evaluate this method given the great deal of new information available.…
We have obtained a mosaic of CCD images of the Coma cluster in the V-band covering a region of approximately 0.4 degrees$^2$ around both central cluster galaxies NGC 4889 and NGC 4874. An additional frame of $\sim$ 90 arcmin$^2$ was taken…
In this paper, we make a comprehensive determination of the Hubble constant $H_0$ by using two parameters - the B-V color and the rate of decline $\Delta m_{15}$ - to simultaneously standardize the luminosities of all nearby…
The three rung distance ladder, which calibrates Type Ia supernovae through stellar distances linked to geometric measurements, provides the highest precision direct measurement of the Hubble constant. In light of the Hubble tension, it is…
We determine the distances to the z~0.55 galaxy clusters MS 0451.6-0305 and CL 0016+16 from a maximum likelihood joint fit to interferometric Sunyaev-Zel'dovich effect (SZE) and X-ray observations. We model the intracluster medium (ICM)…