2007/09/05 by Ignacio Trujillo, Christopher J. Conselice, Kevin Bundy +5 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2007.12388.x
published as Mon.Not.Roy.Astron.Soc.382:109-120,2007 · MNRAS in press, 13 pages, 11 figures. Data Table will be published in its integrity in the MNRAS online version
arxiv created 2007/09/05 · openalex publication_date 2007/10/28 · arxiv updated 2011/06/21 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Abstract Using the combined capabilities of the large near-infrared Palomar/DEEP-2 survey, and the superb resolution of the Advanced Camera for Surveys HST camera, we explore the size evolution of 831 very massive galaxies (M⋆≥ 1011h−270 M⊙) since z∼ 2. We split our sample according to their light concentration using the Sérsic index n. At a given stellar mass, both low (n < 2.5) and high (n > 2.5) concentrated objects were much smaller in the past than their local massive counterparts. This evolution is particularly strong for the highly concentrated (spheroid like) objects. At z∼ 1.5, massive spheroid-like objects were a factor of 4 (±0.4) smaller (i.e. almost two orders of magnitudes denser) than those we see today. These small sized, high-mass galaxies do not exist in the nearby Universe, suggesting that this population merged with other galaxies over several billion years to form the largest galaxies we see today.