In the phenomenon of gravitational lensing, predicted by Einstein's General Theory of Relativity, the mass of a galaxy acts on the light of a more distant object, as if it were a huge lens, producing a distorted image with the form of a so-called Einstein ring or multiple images and a magnification of the total flux, allowing to see details which would otherwise be too faint to detect. GTC/OSIRIS spectroscopic observations allowed to discover one of the brightest galaxies in the early Universe, BG1429+1202, located at a redshift of 2.82 (we see it as it was some 2,300 million years after the Big Bang). BG1429+1202 is a Lyman-Alpha Emitting galaxy (LAE) gravitationally lensed by a massive Early Type galaxy close to the line of sight at a redshift of 0.55. Although typical LAEs are faint and not very luminous, BG1429+1202 is not only apparently bright but also intrinsically very luminous after accounting for the lensing magnification, showing indications of massive star formation. This galaxy-scale strong gravitational system was found in the BELLS GALLERY project that analysed around a million and a half spectra of galaxies obtained with the Sloan Telescope, at the Apache Point Observatory in New Mexico (USA), by the BOSS survey, part of the Sloan Digital Sky Survey III.
It may interest you
-
Dark matter is an invisible substance that makes up more than eighty percent of the matter content of the universe. We know of its existence due to its gravitational influence, being a key ingredient to understand everything from the large-scale evolution of the universe to the formation of galaxies like the Milky Way, of which we are part of. However, very little is known about its nature, which constitutes one of the greatest unsolved problems in contemporary physics. The fuzzy dark matter model has recently been studied as a promising candidate. In this model, it is postulated that dark
Advertised on -
The cosmic evolution of the barred galaxy population provides key information about the secular evolution of galaxies and the settling of rotationally dominated discs. We study the bar fraction in the SMACSJ0723.37323 (SMACS0723) cluster of galaxies at z = 0.39 using the Early Release Observations obtained with the NIRCam instrument mounted on the JWST telescope. We visually inspected all cluster member galaxies using the images from the NIRCam F200W filter. We classified the galaxies into ellipticals and discs and determine the presence of a bar. The cluster member selection was based on a
Advertised on -
H II regions are ionized nebulae associated with the formation of massive stars. They exhibit a wealth of emission lines in their spectra that form the basis for estimation of chemical composition. The amount of heavy chemical elements is essential to the understanding of important phenomena such as nucleosynthesis, star formation and chemical evolution of galaxies. For over 80 years, however, a discrepancy exists of a factor of around two between heavy-element abundances (the so-called metallicity) derived from the two main kinds of emission lines that can be measured in nebular spectra
Advertised on