AstroUnit

  A team of cosmologists compared the theoretical predictions of the maximal abundance of massive galaxies predicted in different dynamical dark energy (DDE) models at high redshifts z ≈ 4 − 7 with the observed abundance and derived constraints for the evolution of the dark energy equation of state parameter which is complementary to the existing probes. The study employed three different, independent probes, namely the luminous end of the stellar mass function at z ≥ 6, the spatial density of luminous galaxies detected in the submillimeter range at z = 4 − 5, and the rareness of the extreme hyperluminous infrared galaxy SPT031158 at z ≈ 7. The analysis excluded a significant fraction of parameter spaces for the DDE models but interestingly does not completely exclude the possibility that dark energy may be dynamical (i.e, changing with time). Deepest visible-light image of the Universe containing nearly 10000 galaxies. Source:  Hubble According to our current understanding of large sc

  A team of astronomers used deep radio observations from 53 MHz to 1.5 GHz with the LOFAR Low/High Band Antenna (LBA/HBA) arrays, the Jansky Very Large Array (JVLA) and the upgraded Giant Metrewave Radio Telescope (GMRT) and discovered the existence of a giant radio bridge connecting two pre-merging galaxy clusters A1758N and A1758S that are ~ 2 Mpc apart. This is the second large-scale radio bridge observed to date in a cluster pair. By studying the radio and X-ray emissions from the radio bridge, the astronomers found clear-cut evidence that the non-thermal phenomena in the intracluster medium (ICM) can be produced in the region of compressed gas in-between infalling systems.  Cluster Merger: Galaxy Clusters Caught in a First Kiss. Source:  Chandra The existence of radio bridges connecting pre-merging galaxy clusters has been confirmed very recently. Hitherto, only two such systems, namely A1758N-A1758S situated at a redshift of z = 0.279 and Abell 399-401 at z= 0.07 have shown t

  A team of astronomers used archival data from The Baryon Oscillation Spectroscopic Survey (BOSS) and the Pantheon supernovae to obtain stringent constraints on the Hubble parameter at $H_{0}=65.1^{+3.0}_{-5.4}  km/s/Mpc$ which differs from the best fit of SH0ES at 95% confidence level. This is the first time the Hubble parameter has been ascertained from the horizon scale at matter-radiation equality and therefore offers a consistency check for standard cosmological physics in the pre-recombination era.   Source:  hdqwalls.com                                                                                                                                                       Until now, there has always been a disagreement in the estimated value of the $H_{0}$ from different sources.  The so-called  "Late universe" measurements that employs the calibrated distance ladder techniques all largely converge to an estimated value of approximately 73 km/s/Mpc. Whereas the "ear

Cosmologists from Visva-Bharati University and Osmania University reported that the stellar mass of galaxies does not encode all of the information about other galactic properties, an assumption long thought to be true. The new study used archival data from the SDSS in conjunction with cosmological simulations to come to this groundbreaking conclusion.  An artist’s impression of the Milky Way galaxy. Photograph: Chen Xiaodian.                         Downloaded from:  The Guardian                            Understanding the formation and evolution of galaxies is  undoubtedly   one of the major goals of modern  cosmology. The integrated stellar mass of a galaxy is thought to be the most fundamental property which  largely influences its structure and evolution. It is often taken as an impression of its  formation history and governs its future evolution. Galaxies assemble gas through both  mergers and as well as various secular processes. This gas upon condensation gives  rise to molec