相关论文: New Facts From the First Galaxy Distance Estimates

All the recent redshift surveys show highly irregular patterns of galaxies on scales of hundreds of megaparsecs such as chains, walls and cells. One of the most powerful catalog of galaxies is represented by the LEDA database that contains…

A major recent evelopment in observational cosmology has been an accurate measurement of the luminosity distance-redshift relation out to redshifts z=0.8 from Type Ia supernova standard candles. The results have been argued as evidence for…

The present rate of the expansion of our Universe, the Hubble constant, can be predicted from the cosmological model using measurements of the early Universe, or more directly measured from the late Universe. But as these measurements…

Galaxies represent the visible fabric of the Universe and there has been considerable progress recently in both observational and theoretical studies. The underlying goal is to understand the present-day diversity of galaxy forms, masses…

In the era of precision cosmology, it is essential to empirically determine the Hubble constant with an accuracy of one per cent or better. At present, the uncertainty on this constant is dominated by the uncertainty in the calibration of…

The detection and identification of distant galaxies is a prominent goal of observational cosmology because distant galaxies are seen as they were in the distant past and hence probe early galaxy formation, due to the cosmologically…

As some of the first known objects to exist in the Universe, Lyman alpha emitting galaxies (LAEs) naturally draw a lot of interest. First discovered over a decade ago, they have allowed us to probe the early Universe, as their strong…

We report on the discovery of Cepheids in the Virgo spiral galaxy NGC 4535, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope. NGC 4535 is one of 18 galaxies observed as a part of The…

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,…

In this work, we obtain Hubble constant ($H_0$) estimates by using two galaxy cluster gas mass fraction measurement samples, Type Ia supernovae luminosity distances, and the validity of the cosmic distance duality relation. Notably, the…

In efforts to demonstrate the linear Hubble law v = Hr from galaxy observations, the underlying simplicity is often obscured by complexities arising from magnitude-limited data. In this paper we point out a simple but previously unremarked…

We undertook a long term project, DIRECT, to obtain the direct distances to two important galaxies in the cosmological distance ladder -- M31 and M33 -- using detached eclipsing binaries (DEBs) and Cepheids. While rare and difficult to…

Two supernovae detected in the Hubble Deep Field using the original December 1995 epoch and data from a shorter (63000 s in F814W) December 1997 visit with HST are discussed. The supernovae (SNe) are both associated with distinct galaxies…

We present the first galaxy counts at 18 microns using the Japanese AKARI satellite's survey at the North Ecliptic Pole (NEP), produced from the images from the NEP-Deep and NEP-Wide surveys covering 0.6 and 5.8 square degrees respectively.…

How did galaxies form and evolve? This is one of the most challenging questions in astronomy today. Answering it requires a careful combination of observational and theoretical work to reliably determine the observed properties of cosmic…

In this paper, we propose an accurate test of the distance-duality (DD) relation, $\eta=D_{L}(z)(1+z)^{-2}/D_{A}(z)=1$ (where $D_{L}$ and $D_{A}$ are the luminosity distances and angular diameter distances, respectively), with a combination…

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,…

Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to…

The use of multiple independent methods with their own systematic uncertainties is crucial for resolving the ongoing tension between local and distant measurements of the Hubble constant ($H_{0}$). While type Ia supernovae (SNe Ia) have…

We present a method to infer reddenings and distances to stars, based only on their broad-band photometry, and show how this method can be used to produce a three-dimensional dust map of the Galaxy. Our method samples from the full…