2006/09/29 by George K. Miley, G. K. Miley, Roderik A. Overzier +25 · 153 citations
Engineering · Physics and Astronomy · #Astronomy and Astrophysical Research #Brightest cluster galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy merger #Interacting galaxy #Redshift #Satellite galaxy #Space Technology and Applications #Type-cD galaxy #astro-ph
paper · pdf · doi:10.1086/508534
published in The Astrophysical Journal 650(1), L29-L32 (IOP Publishing) · 5 pages, 2 figures (reduced to grayscale); ApJ Letters
openalex publication_date 2006/09/29 · arxiv created 2006/10/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a deep image of the radio galaxy MRC 1138-262 taken with the Hubble Space Telescope ( HST ) at a redshift of z = 2.2. The galaxy is known to have properties of a cD galaxy progenitor and be surrounded by a 3 Mpc-sized structure, identified with a protocluster. The morphology shown on the new deep HST ACS image is reminiscent of a spider's web. More than 10 individual clumpy features are observed, apparently star-forming satellite galaxies in the process of merging with the progenitor of a dominant cluster galaxy 11 Gyr ago. There is an extended emission component, implying that star formation was occurring over a 50 × 40 kpc region at a rate of more than 100 M ☉ yr -1 . A striking feature of the newly named "Spiderweb galaxy" is the presence of several faint linear galaxies within the merging structure. The dense environments and fast galaxy motions at the centers of protoclusters may stimulate the formation of these structures, which dominate the faint resolved galaxy populations in the Hubble Ultra Deep Field. The new image provides a unique testbed for simulations of forming dominant cluster galaxies.