Related papers: The Distance to NGC 5128 (Centaurus A)

The extragalactic distance scale is perhaps the most important application of stellar distance indicators. Among these, classical Cepheids are high-accuracy standard candles that support a $1.4\%$ measurement of Hubble's constant, $H_0$.…

The distance to the fireworks galaxy NGC 6946 is highly uncertain. Recent distance estimates using the tip of the red giant branch of 7.7 to 7.8 Mpc are larger than the distance commonly assumed for studying supernovae in this galaxy of 5.9…

The Tip of the Red Giant Branch (TRGB)-based distance method in the I band is one of the most efficient and precise techniques for measuring distances to nearby galaxies (D <= 15 Mpc). The TRGB in the near infrared (NIR) is 1 to 2…

The tip of the red giant (TRGB) is a standardizable candle and is identifiable as the discontinuity at the bright extreme of the red giant branch (RGB) stars in color-magnitude diagram (CMD) space. The TRGB-based distance method has been…

The J-region asymptotic giant branch (JAGB) method is a new standard candle that is based on the stable intrinsic J-band magnitude of color-selected carbon stars, and has a precision comparable to other primary distance indicators such as…

Long Period Variable stars are ubiquitous among the bright red giant branch stars in NGC 5128. Mostly they are found to be brighter than the tip of the first ascent giant branch with magnitudes ranging from about K=19 to K=21.5. They have…

The active galaxy NGC 4151 has a crucial role as one of only two active galactic nuclei for which black hole mass measurements based on emission line reverberation mapping can be calibrated against other dynamical methods. Unfortunately,…

A measurement of the distance to Virgo Cluster by a direct method along with a realistic error analysis is important for a reliable determination of the value of Hubble Constant. Cepheid variables in the face-on spiral M100 in the Virgo…

We report on our ongoing, high-resolution study of H2O masers in the innermost parsec of NGC 4258. Over thirty epochs of VLBA and VLA data, taken over six years, are being used to monitor the velocities, accelerations, positions and proper…

In the era of precision cosmology it is essential to determine the Hubble Constant with an accuracy of 3% or better. Currently, its uncertainty is dominated by the uncertainty in the distance to the Large Magellanic Cloud (LMC) which as the…

We present a measurement of the Hubble constant made using geometric distance measurements to megamaser-hosting galaxies. We have applied an improved approach for fitting maser data and obtained better distance estimates for four galaxies…

Given the recent successful launch of the James Webb Space Telescope, determining robust calibrations of the slopes and absolute magnitudes of the near- to mid-infrared Tip of the Red Giant Branch (TRGB) will be essential to measuring…

We study stars in the J-regions of the asymptotic giant branch (JAGB) of near-infrared color magnitude diagrams in the maser host NGC 4258 and 4 hosts of 6 Type Ia supernovae (SN Ia): NGC 1448, NGC 1559, NGC 5584, and NGC 5643. These clumps…

The Hubble Tension, a >5 sigma discrepancy between direct and indirect measurements of the Hubble constant (H0), has persisted for a decade and motivated intense scrutiny of the paths used to infer H0. Comparing independently-derived…

The final efforts of the HST Key Project on the Extragalactic Distance Scale are presented. Four distance indicators, the Surface Brightness Fluctuation method, the Fundamental Plane for early-type galaxies, the Tully-Fisher relation and…

Type II-plateau supernovae (SNe II-P) are the classic variety of core-collapse events that result from isolated, massive stars with thick hydrogen envelopes intact at the time of explosion. Their distances are now routinely estimated…

We present a revised distance to the nearby galaxy NGC6822 using a new multi-band fit to both previously published and new optical, near- and mid-infrared data for Cepheid variables. The new data presented in this study include multi-epoch…

We have used the Advanced Camera for Surveys aboard the Hubble Space Telescope to obtain F435W, F555W and F814W single-epoch images of six fields in the spiral galaxy NGC 300. Taking advantage of the superb spatial resolution of these…

We present the results of near-infrared observations of extragalactic Cepheids made with the Near Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope. The variables are located in the galaxies IC 1613, IC 4182,…

The cosmic distance scale largely depends on distance determinations to Local Group galaxies. In this sense, the Andromeda Galaxy (M31) is a key rung to better constrain the cosmic distance ladder. A project was started in 1999 to firmly…