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@Article{LaganáLoMaLaCaSc:2015:MeElSt,
               author = "Lagan{\'a}, T. F. and Lovisari, L. and Martins, L. and 
                         Lanfranchi, G. A. and Capelato, Hugo Vicente and Schellenberger, 
                         G.",
          affiliation = "{Universidade Cruzeiro do Sul} and {Universit{\"a}t Bonn} and 
                         {Universidade Cruzeiro do Sul} and {Universidade Cruzeiro do Sul} 
                         and {Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universit{\"a}t Bonn}",
                title = "A metal-rich elongated structure in the core of the group NGC 
                         4325",
              journal = "Astronomy \& Astrophysics",
                 year = "2015",
               volume = "573",
             keywords = "galaxies, NGC 4325, intergalactic medium, halos.",
             abstract = "Aims. Based on XMM-Newton, Chandra, and optical DR10-SDSS data, we 
                         investigate the metal enrichment history of the group NGC 4325 (z 
                         = 0.026). To complete the analysis we used chemical evolution 
                         models and studied the optical spectrum of the central dominant 
                         galaxy through its stellar population analysis and emission line 
                         diagnostics to analyse its role in the metal enrichment of the 
                         intra-group medium. Methods. We used X-ray 2D spectrally resolved 
                         maps to resolve structure in temperature and metallicity. We also 
                         derived gas and total masses within r2500 and r500 assuming 
                         hydrostatic equilibrium and spherical symmetry. To perform stellar 
                         population analysis we applied the spectral fitting technique with 
                         STARLIGHT to the optical spectrum of the central galaxy. We 
                         simulated the chemical evolution of the central galaxy. Results. 
                         While the temperature, pseudo-pressure, and pseudo-entropy maps 
                         showed no inhomogeneities, the spatial distribution of the 
                         metallicity shows a filamentary structure in the core of this 
                         group, which is spatially correlated with the central galaxy, 
                         suggesting a connection between the two. The analysis of the 
                         optical spectrum of the central galaxy showed no contribution by 
                         any recent AGN activity. Using the star formation history as input 
                         to chemical evolution models, we predicted the iron and oxygen 
                         mass released by supernovae (SNe) winds in the central galaxy up 
                         to the present time. Conclusions. Comparing the predicted amount 
                         of mass released by the NGC 4325 galaxy to the ones derived 
                         through X-ray analysis we conclude that the winds from the central 
                         galaxy alone play a minor role in the IGM metal enrichment of this 
                         group inside r2500. The SNe winds are responsible for no more than 
                         3% of it and of the iron mass and 21% of the oxygen mass enclosed 
                         within r2500. Our results suggest that oxygen has been produced in 
                         the early stages of the group formation, becoming well mixed and 
                         leading to an almost flat profile. Instead, the iron distribution 
                         is centrally peaked, indicating that this element is still being 
                         added to the IGM specifically in the core by the SNIa. A possible 
                         scenario to explain the elongated metal-rich structure in the core 
                         of the NGC 4325 is a past AGN activity, in which our results 
                         suggest an episode older than ~107\−108 yrs and younger 
                         than 5 × 108. Through the overall distribution of the galaxies, we 
                         found no signs of recent merger in the group centre that could 
                         explain the metal-rich structure.",
                  doi = "10.1051/0004-6361/201424821",
                  url = "http://dx.doi.org/10.1051/0004-6361/201424821",
                 issn = "0004-6361 and 1432-0746",
             language = "en",
           targetfile = "metal rich.pdf",
        urlaccessdate = "30 nov. 2020"
}


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