49 research outputs found

    Submm-bright QSOs at z~2: signposts of co-evolution at high z

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    We have assembled a sample of 5 X-ray and submm-luminous z~2 QSOs which are therefore both growing their central black holes through accretion and forming stars copiously at a critical epoch. Hence, they are good laboratories to investigate the co-evolution of star formation and AGN. We have performed a preliminary analysis of the AGN and SF contributions to their UV-to-FIR SEDs, fitting them with simple direct (disk), reprocessed (torus) and star formation components. All three are required by the data and hence we confirm that these objects are undergoing strong star formation in their host galaxies at rates 500-2000 Msun/y. Estimates of their covering factors are between about 30 and 90%. In the future, we will assess the dependence of these results on the particular models used for the components and relate their observed properties to the intrinsice of the central engine and the SF material, as well as their relevance for AGN-galaxy coevolution.Comment: 6 pages, 2 figures, contributed talk to "Nuclei of Seyfert galaxies and QSOs - Central engine & conditions of star formation" November 6-8, 2012. MPIfR, Bonn, Germany. Po

    Submm-bright X-ray absorbed QSOs at z~2: insights into the co-evolution of AGN and star-formation

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    We have assembled a sample of 5 X-ray-absorbed and submm-luminous type 1 QSOs at z2z \sim 2 which are simultaneously growing their central black holes through accretion and forming stars copiously. We present here the analysis of their rest-frame UV to submm Spectral Energy Distributions (SEDs), including new Herschel data. Both AGN (direct and reprocessed) and Star Formation (SF) emission are needed to model their SEDs. From the SEDs and their UV-optical spectra we have estimated the masses of their black holes MBH1091010MM_{BH}\sim 10^{9}-10^{10}\,M_{\odot}, their intrinsic AGN bolometric luminosities LBOL(0.820)×1013LL_{BOL}\sim(0.8 - 20)\times 10^{13} L_{\odot}, Eddington ratios LBOL/LEdd0.11.1L_{BOL}/L_{Edd}\sim 0.1 - 1.1 and bolometric corrections LBOL/LX,21030500L_{BOL}/L_{X,2-10}\sim 30 - 500. These values are common among optically and X-ray-selected type 1 QSOs (except for RX~J1249), except for the bolometric corrections, which are higher. These objects show very high far-infrared luminosities LFIRL_{FIR}\sim (2 - 8)×1012M\times10^{12}\,M_{\odot} and Star Formation Rates SFR1000M/\sim 1000 M_{\odot}/y. From their LFIRL_{FIR} and the shape of their FIR-submm emission we have estimated star-forming dust masses of MDUST109MM_{DUST}\sim 10^9\,M_\odot. We have found evidence of a tentative correlation between the gas column densities of the ionized absorbers detected in X-ray (NHion_{H_{ion}}) and SFRSFR. Our computed black hole masses are amongst the most massive known.Comment: Accepted for publication in MNRAS, December 22, 2014, 17 pages, 5 figure

    Star-forming outflowing QSOs at z~2: their status, future and environments

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    Trabajo presentado al Demographics and environment of AGN from multi-wavelength surveys, celebrado en Creta del 21 al 24 de septiembre de 2015.Peer Reviewe

    Herschel-ATLAS: the far-infrared properties and star-formation rates of broad absorption line quasi-stellar objects

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    We have used data from the Herschel-ATLAS at 250, 350 and 500 \mu m to determine the far-infrared (FIR) properties of 50 Broad Absorption Line Quasars (BAL QSOs). Our sample contains 49 high-ionization BAL QSOs (HiBALs) and 1 low-ionization BAL QSO (LoBAL) which are compared against a sample of 329 non-BAL QSOs. These samples are matched over the redshift range 1.5 \leq z < 2.3 and in absolute i-band magnitude over the range -28 \leq M_{i} \leq -24. Of these, 3 BAL QSOs (HiBALs) and 27 non-BAL QSOs are detected at the > 5 sigma level. We calculate star-formation rates (SFR) for our individually detected HiBAL QSOs and the non-detected LoBAL QSO as well as average SFRs for the BAL and non-BAL QSO samples based on stacking the Herschel data. We find no difference between the HiBAL and non-BAL QSO samples in the FIR, even when separated based on differing BAL QSO classifications. Using Mrk 231 as a template, the weighted mean SFR is estimated to be \approx240\pm21 M_{\odot} yr^{-1} for the full sample, although this figure should be treated as an upper limit if AGN-heated dust makes a contribution to the FIR emission. Despite tentative claims in the literature, we do not find a dependence of {\sc C\,iv} equivalent width on FIR emission, suggesting that the strength of any outflow in these objects is not linked to their FIR output. These results strongly suggest that BAL QSOs (more specifically HiBALs) can be accommodated within a simple AGN unified scheme in which our line-of-sight to the nucleus intersects outflowing material. Models in which HiBALs are caught towards the end of a period of enhanced spheroid and black-hole growth, during which a wind terminates the star-formation activity, are not supported by the observed FIR properties.Comment: 11 pages, 4 figures, 4 tables. Accepted for publication in MNRA

    Successful treatment of Candida parapsilosis mural endocarditis with combined caspofungin and voriconazole

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    BACKGROUND: Fungal mural endocarditis is a rare entity in which the antemortem diagnosis is seldom made. Seven cases of mural endocarditis caused by Candida spp. have been collected from literature and six of these patients died after treatment with amphotericin B. CASE PRESENTATION: We report a case of mural endocarditis diagnosed by transesophageal echocardiogram and positive blood cultures to Candida parapsilosis. Because blood cultures continued to yield C. parapsilosis despite caspofungin monotherapy, treatment with voriconazole was added. CONCLUSION: This is the first description of successful treatment of C. parapsilosis mural endocarditis with caspofungin and voriconazole

    New amino and mercapto derivatives of diosmetin

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    89-93New amino and mercapto derivatives of diosmetin 6-14 have been synthesized and characterized. Compounds 6 and 7 have been obtained from the ditosylated derivative 3 by reaction with the corresponding amine. Compounds 8-14 have been prepared from the dibromo derivative 4 and the appropriate amine or thiol

    Synthesis, Crystal-structure Determination and Pharmacological Activity of 7,8,3',4'-tetramethoxyisoflavone

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    The 7,8,3',4'-tetramethoxyisoflavone 2 was synthesized and its structure confirmed by X-ray crystallographic analysis. Pharmacological screening was carried out with this compound in order to assess its pharmacological profile. Isoflavone 2 possessed antiinflamatory activity in the carrageenan oedema test, with a dose-effect relationship comparable to that of hydroxylated flavonoids. It is noteworthy that 2 is one of the few isoflavones efficient as antiinflammatory with complete alkylation of hydroxyl groups
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