The AAS announces its call for applications for the Harlow Shapley Visiting Lectures Program. We are seeking astronomers and host institutions to participate in 2027!

YouTube video by Natasha Tsakos

/PRNewswire/ -- O'Shaughnessy Ventures LLC (OSV), an investment firm that empowers creators, has awarded an O'Shaughnessy Fellowship to Jenny Wagner, an...

YouTube video by Jenny Wagner

Why this physicist says “we are now ready to move on...”

Dr. Jenny Wagner, Astrophysicist

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics

YouTube video by Urknall, Weltall und das Leben

YouTube video by Urknall, Weltall und das Leben

YouTube video by Urknall, Weltall und das Leben

For most galaxies in the cosmos, our knowledge of their motion is limited to line-of-sight velocities from redshift observations. To determine the radial velocity between two galaxies the minor and ma...

The dwarf spheroidal galaxy, Segue 1, is thought to have one of the largest ratios of dark matter to stellar mass. Using orbit-based dynamical models, we model Segue 1, including a dark halo and a cen...

We use numerical simulations to explore biases that arise in dynamical estimates of the mean mass profile for a collection of galaxy clusters that have been stacked to make a composite. There are thre...

The mass of the Local Group (LG), comprising the Milky Way (MW), Andromeda (M31), and their satellites, is crucial for validating galaxy formation and cosmological models. Traditional virial mass esti...

Ostriker is responsible for groundbreaking discoveries that forever changed the way astronomers think about what the universe is made of, including the existence of dark matter.

We present a scheme for numerically solving Maxwell's equations in a weakly perturbed spacetime without introducing the usual geometric optics approximation. Using this scheme, we study light propagat...

For most galaxies in the cosmos, our knowledge of their motion is limited to line-of-sight velocities from redshift observations. To determine the radial velocity between two galaxies the minor and ma...

For most galaxies in the cosmos, our knowledge of their motion is limited to line-of-sight velocities from redshift observations. To determine the radial velocity between two galaxies the minor and ma...

We present the discovery, and initial lensing analysis, of a high-redshift galaxy-galaxy lensing system within the JWST-PEARLS/HST-TREASUREHUNT North Ecliptic Pole Time Domain Field (designated NEPJ17...

The standard model of cosmology has provided a good phenomenological description of a wide range of observations both at astrophysical and cosmological scales for several decades. This concordance mod...

The Lyman-break technique has been used to successfully identify high-redshift candidates in broad-band photometric data in the rest-frame optical and NIR using the dropout technique. We pioneer the a...

The nature of the elusive dark matter can be probed by comparing the predictions of the cold dark matter framework with the gravitational field of massive galaxy clusters. However, a robust test of da...

Modern cosmological theories invoke the idea that all structure in the Universe originates from quantum fluctuations. Understanding the quantum-to-classical transition for these fluctuations is of cen...

Physicists had long assumed that the elusive force has constant strength. But the latest results from a project to map the Universe’s expansion challenge this idea.

We present power spectra of the cosmic microwave background (CMB) anisotropy in temperature and polarization, measured from the Data Release 6 maps made from Atacama Cosmology Telescope (ACT) data. Th...