Browsing by Author "Pierini, D."

Now showing 1 - 7 of 7
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    Discovery of a massive X-ray luminous galaxy cluster at z=1.579
    (2011) Santos, J. S.; Fassbender, R.; Nastasi, A.; Boehringer, H.; Rosati, P.; Suhada, R.; Pierini, D.; Nonino, M.; Muehlegger, M.; Quintana, H.; Schwope, A. D.; Lamer, G.; de Hoon, A.; Strazzullo, V.
    We report on the discovery of a very distant galaxy cluster serendipitously detected in the archive of the XMM-Newton mission, within the scope of the XMM-Newton Distant Cluster Project (XDCP). XMMUJ0044.0-2033 was detected at a high significance level (5 sigma) as a compact, but significantly extended source in the X-ray data, with a soft-band flux f(r < 40 '') = (1.5 +/- 0.3) x 10(-14) erg s(-1) cm(2). Optical/NIR follow-up observations confirmed the presence of an overdensity of red galaxies matching the X-ray emission. The cluster was spectroscopically confirmed to be at z = 1.579 using ground-based VLT/FORS2 spectroscopy. The analysis of the I-H colour-magnitude diagram shows a sequence of red galaxies with a colour range [3.7 < I-H < 4.6] within 1' from the cluster X-ray emission peak. However, the three spectroscopic members (all with complex morphology) have significantly bluer colours relative to the observed red-sequence. In addition, two of the three cluster members have [OII] emission, indicative of on-going star formation. Using the spectroscopic redshift we estimated the X-ray bolometric luminosity, L-bol,L-40 '' similar to 5.8 x 10(44) erg s(-1), implying a massive galaxy cluster. This places XMMU J0044.0-2033 at the forefront of massive distant clusters, closing the gap between lower redshift systems and recently discovered proto-and low-mass clusters at z > 1.6.
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    Distant clusters of galaxies in a deep XMM-Newton observation
    (2013) Hoon, A. de; Lamer, G.; Schwope, A.; Mühlegger, M.; Fassbender, R.; Böhringer, H.; Lerchster, M.; Nastasi, A.; Šuhada, R.; Rosati, P.; Pierini, D.; Santo, J. S.; Quintana Godoy, Hernán
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    Distant galaxy clusters in a deep XMM-Newton field within the CFTHLS D4
    (2013) de Hoon, A.; Lamer, G.; Schwope, A.; Muehlegger, M.; Fassbender, R.; Boehringer, H.; Lerchster, M.; Nastasi, A.; Suhada, R.; Verdugo, M.; Dietrich, J. P.; Brimioulle, F.; Rosati, P.; Pierini, D.; Santos, J. S.; Quintana, H.; Rabitz, A.; Takey, A.
    Aims. The XMM-Newton distant cluster project (XDCP) aims at the identification of a well defined sample of X-ray selected clusters of galaxies at redshifts z >= 0.8. As part of this project, we analyse the deep XMM-Newton exposure covering one of the CFHTLS deep fields to quantify the cluster content. We validate the optical follow-up strategy as well as the X-ray selection function.
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    Exploring the galaxy cluster-group transition regime at high redshifts Physical properties of two newly detected z > 1 systems
    (2011) Suhada, R.; Fassbender, R.; Nastasi, A.; Boehringer, H.; de Hoon, A.; Pierini, D.; Santos, J. S.; Rosati, P.; Muehlegger, M.; Quintana, H.; Schwope, A. D.; Lamer, G.; Kohnert, J.; Pratt, G. W.
    Context. Multi-wavelength surveys for clusters of galaxies are opening a window on the elusive high-redshift (z > 1) cluster population. Well controlled statistical samples of distant clusters will enable us to answer questions about their cosmological context, early assembly phases and the thermodynamical evolution of the intracluster medium.
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    First simultaneous optical/near-infrared imaging of an X-ray selected, high-redshift cluster of galaxies with GROND The galaxy population of XMMU J0338.7+0030 at z=1.1
    (2012) Pierini, D.; Suhada, R.; Fassbender, R.; Nastasi, A.; Boehringer, H.; Salvato, M.; Pratt, G. W.; Lerchster, M.; Rosati, P.; Santos, J. S.; de Hoon, A.; Kohnert, J.; Lamer, G.; Mohr, J. J.; Muehlegger, M.; Quintana, H.; Schwope, A.; Biffi, V.; Chon, G.; Giodini, S.; Koppenhoefer, J.; Verdugo, M.; Ziparo, F.; Afonso, P. M. J.; Clemens, C.; Greiner, J.; Kruehler, T.; Yoldas, A. Kuepcue; Olivares E, F.; Rossi, A.; Yoldas, A.
    Context. The XMM-Newton Distant Cluster Project is a serendipitous survey for clusters of galaxies at redshifts z >= 0.8 based on deep archival XMM-Newton observations. X-ray sources identified as extended are screened against existing optical all-sky surveys for galaxies, in case of candidate high-z clusters followed up with imaging at 4 m-class telescopes and, ultimately, multi-object spectroscopy at 8 m-class telescopes. Low-significance candidate high-z clusters are followed up with the seven-channel imager GROND (Gamma-Ray Burst Optical and Near-Infrared Detector) that is mounted at a 2 m-class telescope. Its unique capability of simultaneous imaging in the g', r', i', z', J, H, Ks bands enables the use of the photometric redshift technique.
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    Galaxy population properties of the massive X-ray luminous galaxy cluster XDCP J0044.0-2033 at z=1.58
    (2014) Fassbender, R.; Santos, J.; Verdugo, M.; Lidman, C.; Koyama, Y.; Rosati, P.; Pierini, D.; Romeo, A.; Padilla, Nelson; Nastasi, A.