NGC 4676 — LLMpedia

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NGC 4676 NGC 4676 is a famous interacting pair of galaxies in the constellation Coma Berenices known colloquially as a "pair" that displays dramatic tidal features. The system is embedded in the Coma Cluster region and has been the subject of studies by instruments such as the Hubble Space Telescope, the Chandra X-ray Observatory, the Spitzer Space Telescope, and ground facilities including the Keck Observatory, the Very Large Array, and the Sloan Digital Sky Survey. The object appears in catalogs compiled by organisations like the New General Catalogue, the Atlas of Peculiar Galaxies by Halton Arp, and the Vorontsov-Velyaminov catalog.

Overview

The system is catalogued as a pair of interacting disk galaxies distinguished by long tidal tails and a "hinge" morphology noted in imaging from Hubble Space Telescope programs and surveys such as Sloan Digital Sky Survey. Observers associate the pair with the Coma Berenices sky region near the Coma Cluster and the Virgo Supercluster large-scale structure; redshift-based distance estimates place it at tens of megaparsecs, comparable to distances used in studies by teams at Harvard–Smithsonian Center for Astrophysics and the Max Planck Institute for Astronomy. It is cited widely in reviews of galaxy interactions by authors connected to institutions such as the California Institute of Technology, Princeton University, and the European Southern Observatory.

The disrupted pair entered the literature through nineteenth-century cataloguing efforts associated with the New General Catalogue compiled by John Louis Emil Dreyer and later drew attention in the twentieth century via the Atlas of Peculiar Galaxies by Halton Arp. Subsequent imaging and spectroscopic campaigns involved observatories and facilities across the globe: imaging from Palomar Observatory and spectrographs on Keck Observatory delivered kinematic data that were complemented by radio observations from the National Radio Astronomy Observatory and the Westerbork Synthesis Radio Telescope. Spaceborne follow-up by Hubble Space Telescope instruments (notably Wide Field Planetary Camera 2 and Advanced Camera for Surveys), ultraviolet data from Galaxy Evolution Explorer, infrared measurements by Spitzer Space Telescope and the Infrared Astronomical Satellite, and X-ray mapping with Chandra X-ray Observatory and XMM-Newton have made the pair a benchmark in interaction studies cited in papers from teams at University of California, Berkeley, University of Cambridge, and University of Toronto.

The morphology shows two disk galaxies with prominent tidal tails, bridges, and disturbed central regions that have been modeled in simulation comparisons performed by researchers at California Institute of Technology and Rutgers University. High-resolution optical imaging from Hubble Space Telescope reveals star clusters and dust lanes in the disturbed disks, while near-infrared data from Spitzer Space Telescope and ground-based facilities such as the United Kingdom Infrared Telescope help trace older stellar populations studied by researchers at University of Oxford and University of Edinburgh. Morphological classification discussions appear in work by teams associated with Max Planck Institute for Astrophysics and Carnegie Institution for Science who contrast the system with interacting examples like those in the Toomre sequence and other entries in Halton Arp's catalog.

Spectroscopic mapping using instruments at Keck Observatory, the Very Large Telescope, and the Anglo-Australian Telescope has provided velocity fields that underpin dynamical modeling by groups at University of Michigan and Yale University. Neutral hydrogen imaging from the Very Large Array and Arecibo Observatory (historically) reveals extended H I tails used in angular momentum analyses by researchers at the National Radio Astronomy Observatory and the University of Groningen. Numerical simulations carried out by teams at Harvard University, Institute for Advanced Study, and University of California, Santa Cruz reproduce the kinematic signatures via prograde encounters and produce tidal features resembling those catalogued by B. T. T. Lynds and Alar Toomre. The system's dynamics are often compared with interaction simulations from the Illustris and EAGLE projects and analytic work by researchers linked to Princeton University and Space Telescope Science Institute.

Multiwavelength indicators from far-ultraviolet imaging by Galaxy Evolution Explorer, optical spectroscopy from Sloan Digital Sky Survey, and infrared photometry from Spitzer Space Telescope and WISE show regions of enhanced star formation concentrated in tidal knots and central disk regions. Studies led by groups at University of Colorado Boulder and University of Arizona identified young massive star clusters similar to those in systems studied by teams at Johns Hopkins University and University of Cambridge. Stellar population synthesis applied by researchers at University of Oxford and Max Planck Institute for Astronomy indicates a mix of young (<100 Myr) clusters and older disk stars consistent with bursts triggered by the encounter, a phenomenon also discussed in literature from Carnegie Institution for Science and Observatoire de Paris.

Dynamical models by researchers at California Institute of Technology and Rutgers University suggest the pair is in an early-to-intermediate stage of a major merger, with tidal tails indicating a close passage within the last few hundred million years; similar evolutionary paths are described in merger studies from Toomre & Toomre and numerical work by investigators at Max Planck Institute for Astrophysics and University of California, Berkeley. Predictions derived from N-body and hydrodynamic simulations at Harvard–Smithsonian Center for Astrophysics and Princeton University indicate eventual coalescence into a single remnant resembling systems discussed in reviews by Francesco Shankar and colleagues at European Southern Observatory and potentially evolving toward an early-type morphology similar to galaxies catalogued by Faber–Jackson and analyzed in surveys by Sloan Digital Sky Survey teams.

X-ray observations from Chandra X-ray Observatory detect hot gas and point sources interpreted in studies by teams at Massachusetts Institute of Technology and Columbia University; infrared maps from Spitzer Space Telescope and WISE reveal dust-obscured star-forming regions probed by researchers at Jet Propulsion Laboratory and IPAC. Radio continuum from the Very Large Array and molecular gas traced by CO observations at facilities like the IRAM 30m telescope highlight cold gas reservoirs referenced in work by groups at Institut d'Astrophysique de Paris and Max Planck Institute for Radio Astronomy. The system's dramatic tidal tails and compact star clusters make it a widely cited case in reviews and textbooks from authors at University of Chicago, University College London, and California Institute of Technology.

Category:Interacting galaxies Category:Coma Berenices