2005/08/05 by Neal A. Miller · 2 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Gamma-ray bursts and supernovae #LOFAR #Luminous infrared galaxy #Radio galaxy #Star formation #Supercluster (genetic) #astro-ph
paper · pdf · doi:10.1086/497165
published as Astron.J.130:2541-2558,2005 · Accepted by AJ; 50 pages, including 16 figures (for full resolution PDF, see http://mywebpages.comcast.net/nealamiller2/Shapley_pp.pdf)
arxiv created 2005/08/05 · openalex publication_date 2005/11/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
The core of the Shapley supercluster (A3556, A3558, SC 1327-312, SC 1329-313, and A3562) is an ideal region in which to study the effects of cluster mergers on the activity of individual galaxies. This paper presents the most comprehensive radio continuum investigation of the region, relying on a 63 pointing mosaic obtained with the Very Large Array yielding an areal coverage of nearly 7 deg 2 . The mosaic provides a typical sensitivity of about 80 μJy at a resolution of 16'', enabling the detection of galaxies with star formation rates as low as 1 M ⊙ yr -1 . The radio data are complemented by optical imaging in the B and R bands, producing a catalog of 210 radio-detected galaxies with m R ≤ 17.36 ( M R ≤ -19). At least 104 of these radio-detected galaxies are members of the supercluster on the basis of public velocity measurements. Across the entire core of the supercluster, there appears to be a significant deficit of radio galaxies at intermediate optical magnitudes (-21 ≥ M R > -22). This deficit is offset somewhat by an increase in the frequency with which brighter galaxies ( M R ≤ -22) host radio sources. More dramatic is the highly significant increase in the probability for fainter galaxies (-20 ≥ M R > -21) in the vicinity of A3562 and SC 1329-313 to be associated with radio emission. The radio and optical data for these sources strongly suggest that these active galaxies are powered by star formation. In conjunction with recent X-ray analysis, this is interpreted as young starbursts related to the recent merger of SC 1329-313 with A3562 and the rest of the supercluster.