2009/01/22 by N. A. Hatch, R. A. Overzier, J. D. Kurk +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy merger #Radio Astronomy Observations and Technology #Radio galaxy #Satellite galaxy #Stars #Stellar mass #Type-cD galaxy #X-shaped radio galaxy #astro-ph.CO
paper · pdf · doi:10.1111/j.1365-2966.2009.14525.x
12 pages, accepted for publication in MNRAS
arxiv created 2009/01/22 · openalex publication_date 2009/03/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the stellar mass assembly of the Spiderweb galaxy (MRC 1138−262), a massive z= 2.2 radio galaxy in a protocluster and the probable progenitor of a brightest cluster galaxy. Nearby protocluster galaxies are identified and their properties are determined by fitting stellar population models to their rest-frame ultraviolet to optical spectral energy distributions. We find that within 150 kpc of the radio galaxy the stellar mass is centrally concentrated in the radio galaxy, yet most of the dust-uncorrected, instantaneous star formation occurs in the surrounding low-mass satellite galaxies. We predict that most of the galaxies within 150 kpc of the radio galaxy will merge with the central radio galaxy by z= 0, increasing its stellar mass by up to a factor of ≃2. However, it will take several hundred Myr for the first mergers to occur, by which time the large star formation rates are likely to have exhausted the gas reservoirs in the satellite galaxies. The tidal radii of the satellite galaxies are small, suggesting that stars and gas are being stripped and deposited at distances of tens of kpc from the central radio galaxy. These stripped stars may become intracluster stars or form an extended stellar halo around the radio galaxy, such as those observed around cD galaxies in cluster cores.