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Title: NGC 1277: A MASSIVE COMPACT RELIC GALAXY IN THE NEARBY UNIVERSE

As early as 10 Gyr ago, galaxies with more than 10{sup 11} M {sub ☉} of stars already existed. While most of these massive galaxies must have subsequently transformed through on-going star formation and mergers with other galaxies, a small fraction (≲0.1%) may have survived untouched until today. Searches for such relic galaxies, useful windows to explore the early universe, have been inconclusive to date: galaxies with masses and sizes like those observed at high redshift (M {sub *} ≳ 10{sup 11} M {sub ☉}; R{sub e} ≲ 1.5 kpc) have been found in the local universe, but their stars are far too young for the galaxy to be a relic galaxy. This paper explores the first case of a nearby galaxy, NGC 1277 (at a distance of 73 Mpc in the Perseus galaxy cluster), which fulfills many criteria to be considered a relic galaxy. Using deep optical spectroscopy, we derive the star formation history along the structure of the galaxy: the stellar populations are uniformly old (>10 Gyr) with no evidence for more recent star formation episodes. The metallicity of their stars is super-solar ([Fe/H] = 0.20 ± 0.04 with a smooth decline toward the outer regions) and α-enriched ([α/Fe] = 0.4 ±more » 0.1). This suggests a very short formation time scale for the bulk of the stars in this galaxy. This object also rotates very fast (V {sub rot} ∼ 300 km s{sup –1}) and has a large central velocity dispersion (σ > 300 km s{sup –1}). NGC 1277 allows the exploration in full detail of properties such as the structure, internal dynamics, metallicity, and initial mass function as they were at ∼10-12 Gyr ago when the first massive galaxies were built.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4]
  1. Instituto de Astrofísica de Canarias, c/Vía Láctea s/n, E-38205-La Laguna, Tenerife (Spain)
  2. Subaru Telescope, 650 North A'ohoku Place, Hilo, HI 96720 (United States)
  3. Isaac Newton Group of Telescopes, E-38700 Santa Cruz de La Palma, Canary Islands (Spain)
  4. Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049, Cantoblanco, Madrid (Spain)
Publication Date:
OSTI Identifier:
22364058
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 780; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTROSCOPY; GALACTIC EVOLUTION; GALAXIES; GALAXY CLUSTERS; METALLICITY; PHOTOMETRY; RED SHIFT; STAR CLUSTERS; STAR EVOLUTION; STARS; UNIVERSE; VELOCITY