@Article{OSullivanZVGTDPMR:2014:AcNuSt,
               author = "O'Sullivan, E. and Zezas, A. and Vrtilek, J. M. and Giacintucci, 
                         S. and Trevisan, Marina and David, L. P. and Ponman, T. J. and 
                         Mamon, G. A. and Raychaudhury, S.",
          affiliation = "Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. and 
                         Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.; Univ 
                         Crete, Dept Phys, GR-71003 Iraklion, Crete, Greece.; Univ Crete, 
                         Inst Theoret \& Computat Phys, GR-71003 Iraklion, Crete, Greece. 
                         and Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. 
                         and Univ Maryland, Dept Astron, College Pk, MD 20742 USA.; Univ 
                         Maryland, Joint Space Sci Inst, College Pk, MD 20742 USA. and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)} and Harvard 
                         Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. and Univ 
                         Birmingham, Sch Phys \& Astron, Birmingham B15 2TT, W Midlands, 
                         England. and CNRS, UMR 7095, Inst Astrophys Paris, F-75014 Paris, 
                         France.; UMPC, F-75014 Paris, France. and Univ Birmingham, Sch 
                         Phys \& Astron, Birmingham B15 2TT, W Midlands, England.; 
                         Presidency Univ, Dept Phys, Kolkata 700073, India.",
                title = "Deep chandra observations of hcg 16. i. active nuclei, star 
                         formation, and galactic winds",
              journal = "Astrophysical Journal",
                 year = "2014",
               volume = "793",
               number = "2",
                month = "Oct.",
             keywords = "galaxies: active, galaxies: groups: individual (HCG 16), galaxies: 
                         individual (NGC 833, NGC 835, NGC 838, NGC 839, NGC 848), 
                         galaxies: starburst, X-rays: galaxies.",
             abstract = "We present new, deep Chandra X-ray and Giant Metrewave Radio 
                         Telescope 610 MHz observations of the spiral-galaxy-rich compact 
                         group HCG 16, which we use to examine nuclear activity, star 
                         formation, and high-luminosity X-ray binary populations in the 
                         major galaxies. We confirm the presence of obscured active nuclei 
                         in NGC 833 and NGC 835, and identify a previously unrecognized 
                         nuclear source in NGC 838. All three nuclei are variable on 
                         timescales of months to years, and for NGC 833 and NGC 835 this is 
                         most likely caused by changes in accretion rate. The deep Chandra 
                         observations allow us to detect for the first time an Fe K alpha 
                         emission line in the spectrum of the Seyfert 2 nucleus of NGC 835. 
                         We find that NGC 838 and NGC 839 are both starburst-dominated 
                         systems, with only weak nuclear activity, in agreement with 
                         previous optical studies. We estimate the star formation rates in 
                         the two galaxies from their X-ray and radio emission, and compare 
                         these results with estimates from the infrared and ultraviolet 
                         bands to confirm that star formation in both galaxies is probably 
                         declining after galaxy-wide starbursts were triggered similar to 
                         400-500 Myr ago. We examine the physical properties of their 
                         galactic superwinds, and find that both have temperatures of 
                         similar to 0.8 keV. We also examine the X-ray and radio properties 
                         of NGC 848, the fifth largest galaxy in the group, and show that 
                         it is dominated by emission from its starburst.",
                  doi = "10.1088/0004-637X/793/2/73",
                  url = "http://dx.doi.org/10.1088/0004-637X/793/2/73",
                 issn = "0004-637X and 1538-4357",
                label = "isi 2014-11 OSullivanZVGTDPMR:2014:ACNUST",
             language = "en",
           targetfile = "1407.7543.pdf",
        urlaccessdate = "11 maio 2024"
}