Related papers: The Distance to NGC 5128 (Centaurus A)
We report the results of an [O III] lambda 5007 survey for planetary nebulae (PN) in three spiral galaxies: M101 (NGC 5457), M51 (NGC 5194/5195) and M96 (NGC 3368). By comparing on-band/off-band [O III] lambda 5007 images with images taken…
This research paper aims to compare different methods for calculating the distance to the Large Magellanic Cloud (\textit{LMC}). The distance, $d_{LMC}$, is determined using stellar parallax, variable stars (RR Lyrae and Classical…
Repeated imaging observations of NGC 4395 were made with the WIYN 3.5 m and the KPNO 2.1 m telescopes. From the photometry of the resolved brighter stars in this galaxy eleven Cepheids with periods ranging between 12 and 90 days have been…
Centaurus A, with its gas-rich elliptical host galaxy, NGC 5128, is the nearest radio galaxy at a distance of 3.8 Mpc. Its proximity allows us to study the interaction between an active galactic nucleus, radio jets, and molecular gas in…
As the nearest accessible massive early-type galaxy, NGC 5128 presents an exceptional opportunity to measure dark matter halo parameters for a representative elliptical galaxy. Here we take advantage of rich new observational datasets of…
NGC 5128, a giant elliptical galaxy only $\sim 4$ Mpc away, is the dominant member of a galaxy group of over 80 probable members. The Centaurus group provides an excellent sample for a kinematic comparison between the halo of NGC 5128 and…
The brightness of the tip of the red-giant branch (TRGB) allows one to constrain novel energy losses that would lead to a larger core mass at helium ignition and thus to a brighter TRGB than expected by standard stellar models. The required…
New and existing X-ray, UBVJHKsW(1-4), and spectroscopic observations were analyzed to constrain fundamental parameters for M25, NGC 7790, and dust along their sight-lines. The star clusters are of particular importance given they host the…
The distance to NGC 7331 has been derived from Cepheid variables observed with HST/WFPC2, as part of the Extragalactic Distance Scale Key Project. Multi-epoch exposures in F555W (V) and F814W (I), with photometry derived independently from…
Considerable progress has been made in determining the Hubble constant over the past two decades. We discuss the cosmological context and importance of an accurate measurement of the Hubble constant, and focus on six high-precision…
Several standard candles have been tested and used to measure accurate extragalactic distances over the past decades. There have been discussions regarding the possibility of using Type-II Cepheids (T2Cs) as an alternative tool, but rarely…
We present deep GALEX images of NGC 5128, the parent galaxy of Centaurus A. We detect a striking "weather ribbon" of Far-UV and H$\alpha$ emission, which extends more than 35 kpc northeast of the galaxy. The ribbon is associated with a…
We present final results of a program for the determination of the Hubble constant based on the calibration of the Type Ia supernovae (SNe Ia) using the Tip of the Red Giant Branch (TRGB). We report TRGB distances to three SN Ia host…
The Carnegie-Chicago Hubble Program seeks to anchor the distance scale of Type Ia supernovae via the Tip of the Red Giant Branch (TRGB). Based on deep $Hubble$ $Space$ $Telescope$ ACS/WFC imaging, we present an analysis of the TRGB for the…
Distance measurements to extragalactic systems that are both accurate and precise are cornerstones of modern astrophysics, underpinning the calibration of standard candles and the determination of the Hubble constant. Dwarf galaxies, such…
The distance to LMC and SMC is a subject of controversy, with the difference between the extreme values in distance moduli exceeding 0.5 mag. While currently the best calibrated method is based on red clump giants, and the near future…
We present a new determination of the distance to M101, host of the type Ia SN 2011fe, based on the tip of the red giant branch method (TRGB). Our determination is based on {\it Hubble Space Telescope} archival $F555W$ and $F814W$ images of…
The luminosity of the Tip of the Red Giant Branch (TRGB) provides an excellent measure of galaxy distances and is easily determined in the resolved images of nearby galaxies observed with Hubble Space Telescope. There is now a large amount…
This paper starts with a brief historical review about the PNLF and its use as a distance indicator. Then the PNLF distances are compared with Surface Brightness Fluctuations (SBF) distances and Tip of the Red Giant Branch (TRGB) distances.…
We present year-long, near-infrared Hubble Space Telescope WFC3 observations of Mira variables in the water megamaser host galaxy NGC 4258. Miras are AGB variables that can be divided into oxygen- (O-) and carbon- (C-) rich subclasses.…