September 15, 2018

  • Hubble Captures Wide-Field View of Galaxy Cluster Abell 370

    image_6407-Abell-370Abell 370, a massive galaxy cluster located in the constellation Cetus, approximately 4 billion light-years away, is the first target of the BUFFALO survey, which aims to search for some of the first galaxies in the Universe. Image credit: NASA / ESA / A. Koekemoer / M. Jauzac / C. Steinhardt / BUFFALO Team.

    The immense mass of giant galaxy clusters like Abell 370, mainly composed of the mysterious dark matter, bends and magnifies the light of these faraway objects, turning these clusters into natural telescopes.

    A cluster’s mass bends and magnifies light from more distant objects behind it, uncovering objects otherwise too faint for even Hubble’s sensitive vision.

    Using this cosmological trick — known as strong gravitational lensing — Hubble is able to explore some of the earliest and most distant galaxies in the Universe.

    The most stunning demonstration of gravitational lensing in Abell 370 can be seen just below the center of the cluster.

    Nicknamed ‘The Dragon,’ this feature is a combination of five gravitationally lensed images of the same spiral galaxy that lies beyond the cluster.

    This image of Abell 370 and its surroundings was made as part of the new Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO) survey.

    This project was designed to succeed the successful Frontier Fields project. 101 Hubble orbits have been dedicated to exploring the six Frontier Field galaxy clusters. These additional observations focus on the regions surrounding the galaxy clusters, allowing for a larger field of view.

    BUFFALO’s main mission, however, is to investigate how and when the most massive and luminous galaxies in the Universe formed and how early galaxy formation is linked to dark matter assembly.

    This will allow astronomers to determine how rapidly galaxies formed in the first 800 million years after the Big Bang.

    Driven by the Frontier Fields observations, the BUFFALO survey will be able to detect the most distant galaxies 10 times more efficiently than its progenitor program.

    BUFFALO will also take advantage of other space telescopes which have already observed the regions around the clusters. These datasets will be included in the search for the first galaxies.

    “By expanding the area that we map around each of these clusters, we will significantly improve our estimate of the clusters’ magnification, a mandatory step for studying the distant galaxies that BUFFALO will discover,” said BUFFALO project leader Dr. Mathilde Jauzac, an astronomer in the Centre for Extragalactic Astronomy at Durham University, UK.

    “Plus, BUFFALO will allow us to map precisely the distribution of dark matter in these massive clusters, and thus trace their evolutionary history, a missing piece of information in today’s evolution theories.”

    “BUFFALO represents an amazing opportunity to understand how dark matter assembles, interacts, and evolves in the most massive structures present in our Universe.”