90 research outputs found

    A powerful radio-loud quasar at the end of cosmic reionization

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    We present the discovery of the radio-loud quasar PSO J352.4034-15.3373 at z=5.84 pm 0.02. This quasar is the radio brightest source known, by an order of magnitude, at z~6 with a flux density in the range of 8-100 mJy from 3GHz to 230MHz and a radio loudness parameter R>~1000. This source provides an unprecedented opportunity to study powerful jets and radio-mode feedback at the highest redshifts, and presents the first real chance to probe deep into the neutral intergalactic medium by detecting 21 cm absorption at the end of cosmic reionization.Comment: ApJL accepted on May 8, 2018. See the companion paper by Momjian et a

    Registro de histeroscopias durante el período 2016-2017, hallazgos anatomopatológicos

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    La Histeroscopía es un procedimiento que permite al ginecólogo observar el interior de vagina, cuello y cuerpo uterino. Este procedimiento puede realizarse con fines diagnósticos y terapeúticos. Se indica para el tratamiento de miomas uterinos de localización submucosa, pólipos endometriales, malformaciones uterinas, sinequias. Se indica también para el estudio y diagnóstico de sangrados uterinos anormales, hemorragia genital de la postmenopausia, engrosamiento endoemtrial. También, con el instrumental adecuado, sirve para retirar cuerpos extraños, como metaplasia ósea, Dispositivo intrauterino retenido. La Histeroscopía juega un rol importante en la medicina reproductiva. Siempre que una Histerosalpingografía muestre alguna alteración de la cavidad uterina es indispensable realizar una Histeroscopía. Objetivos: realizar un registro de Histeroscopías llevadas a cabo en el Htal. Italiano La Plata en el período 2016-2017, evaluando las patologías más frecuentes y su rango etario de prevalencia.Facultad de Ciencias Médica

    Mapping the Lyman-Alpha Emission Around a z~6.6 QSO with MUSE: Extended Emission and a Companion at Close Separation

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    We utilize the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) to search for extended Lyman-Alpha emission around the z~6.6 QSO J0305-3150. After carefully subtracting the point-spread-function, we reach a nominal 5-sigma surface brightness limit of SB = 1.9x1018^{-18} erg/s/cm2^2/arcsec2^2 over a 1 arcsec2^2 aperture, collapsing 5 wavelength slices centered at the expected location of the redshifted Lyman-Alpha emission (i.e. at 9256 Ang.). Current data suggest the presence (5-sigma, accounting for systematics) of a Lyman-Alpha nebula that extends for 9 kpc around the QSO. This emission is displaced and redshifted by 155 km/s with respect to the location of the QSO host galaxy traced by the [CII] emission line. The total luminosity is L = 3.0x1042^{42} erg/s. Our analysis suggests that this emission is unlikely to rise from optically thick clouds illuminated by the ionizing radiation of the QSO. It is more plausible that the Lyman-Alpha emission is due to fluorescence of the highly ionized optically thin gas. This scenario implies a high hydrogen volume density of nH_H ~ 6 cm3^{-3}. In addition, we detect a Lyman-Alpha emitter (LAE) in the immediate vicinity of the QSO: i.e., with a projected separation of 12.5 kpc and a line-of-sight velocity difference of 560 km/s. The luminosity of the LAE is L = 2.1x1042^{42} erg/s and its inferred star-formation-rate is SFR ~ 1.3 M_\odot/yr. The probability of finding such a close LAE is one order of magnitude above the expectations based on the QSO-galaxy cross-correlation function. This discovery is in agreement with a scenario where dissipative interactions favour the rapid build-up of super-massive black holes at early Cosmic times.Comment: 17 pages, 15 figures. Accepted for publication in Ap

    Mapping the Lyman-Alpha Emission Around a z~6.6 QSO with MUSE: Extended Emission and a Companion at Close Separation

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    We utilize the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) to search for extended Lyman-Alpha emission around the z~6.6 QSO J0305-3150. After carefully subtracting the point-spread-function, we reach a nominal 5-sigma surface brightness limit of SB = 1.9x1018^{-18} erg/s/cm2^2/arcsec2^2 over a 1 arcsec2^2 aperture, collapsing 5 wavelength slices centered at the expected location of the redshifted Lyman-Alpha emission (i.e. at 9256 Ang.). Current data suggest the presence (5-sigma, accounting for systematics) of a Lyman-Alpha nebula that extends for 9 kpc around the QSO. This emission is displaced and redshifted by 155 km/s with respect to the location of the QSO host galaxy traced by the [CII] emission line. The total luminosity is L = 3.0x1042^{42} erg/s. Our analysis suggests that this emission is unlikely to rise from optically thick clouds illuminated by the ionizing radiation of the QSO. It is more plausible that the Lyman-Alpha emission is due to fluorescence of the highly ionized optically thin gas. This scenario implies a high hydrogen volume density of nH_H ~ 6 cm3^{-3}. In addition, we detect a Lyman-Alpha emitter (LAE) in the immediate vicinity of the QSO: i.e., with a projected separation of 12.5 kpc and a line-of-sight velocity difference of 560 km/s. The luminosity of the LAE is L = 2.1x1042^{42} erg/s and its inferred star-formation-rate is SFR ~ 1.3 M_\odot/yr. The probability of finding such a close LAE is one order of magnitude above the expectations based on the QSO-galaxy cross-correlation function. This discovery is in agreement with a scenario where dissipative interactions favour the rapid build-up of super-massive black holes at early Cosmic times.Comment: 17 pages, 15 figures. Accepted for publication in Ap

    Hiperandrogenismo secundario a tumor de células de Leydig de ovario en paciente postmenopáusica

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    El tumor de células de Leydig, también llamado tumor de células del hilio o tumor de Berger. Constituye uno de los tipos de tumores originados en los cordones sexuales y mesénquima específico. Es un tumor productor de andrógenos y, por lo tanto, masculinizante. Suelen ser unilaterales y de evolución benigna. Corresponden a menos del 0,5% de los tumores ováricos. Dentro de las distintas patologías que cursan con hiperandrogenismo, el 70-80% corresponde al Sme. de ovario poliquístico, seguido del hirsutismo idiopático 5-15%, Hiperplasia suprarrenal congénita 1-8% y siendo una causa infrecuente, los tumores productores de andrógenos: 0,01-0,3%. Estos tumores pueden se de origen ováricos o adrenales. Es por eso, que es indispensable la valoración bioquímica como imagenológica. Objetivos: reporte de caso de paciente femenina con hiperandrogenismo de larga data y Sme metabólico, sin hallazgos patológicos en ecografía o tomografía que pudieran justificar la causa del exceso de andrógenos circulantes.Facultad de Ciencias Médica

    Copious Amounts of Dust and Gas in a z=7.5 Quasar Host Galaxy

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    We present IRAM/NOEMA and JVLA observations of the quasar J1342+0928 at z=7.54 and report detections of copious amounts of dust and [CII] emission in the interstellar medium (ISM) of its host galaxy. At this redshift, the age of the universe is 690 Myr, about 10% younger than the redshift of the previous quasar record holder. Yet, the ISM of this new quasar host galaxy is significantly enriched by metals, as evidenced by the detection of the [CII] 158micron cooling line and the underlying far-infrared (FIR) dust continuum emission. To the first order, the FIR properties of this quasar host are similar to those found at a slightly lower redshift (z~6), making this source by far the FIR-brightest galaxy known at z>7.5. The [CII] emission is spatially unresolved, with an upper limit on the diameter of 7 kpc. Together with the measured FWHM of the [CII] line, this yields a dynamical mass of the host of <1.5x10^11 M_sun. Using standard assumptions about the dust temperature and emissivity, the NOEMA measurements give a dust mass of (0.6-4.3)x10^8 M_sun. The brightness of the [CII] luminosity, together with the high dust mass, imply active ongoing star formation in the quasar host. Using [CII]-SFR scaling relations, we derive star formation rates of 85-545 M_sun/yr in the host, consistent with the values derived from the dust continuum. Indeed, an episode of such past high star formation is needed to explain the presence of ~10^8 M_sun of dust implied by the observations.Comment: 8 pages, 4 figures. Published in ApJ Letter

    A metal-poor damped Ly-alpha system at redshift 6.4

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    We identify a strong Ly-alpha damping wing profile in the spectrum of the quasar P183+05 at z=6.4386. Given the detection of several narrow metal absorption lines at z=6.40392, the most likely explanation for the absorption profile is that it is due to a damped Ly-alpha system. However, in order to match the data a contribution of an intergalactic medium 5-38% neutral or additional weaker absorbers near the quasar is also required. The absorption system presented here is the most distant damped Ly-alpha system currently known. We estimate an HI column density (1020.68±0.2510^{20.68\pm0.25}\,cm2^{-2}), metallicity ([O/H]=2.92±0.32=-2.92\pm 0.32), and relative chemical abundances of a system consistent with a low-mass galaxy during the first Gyr of the universe. This object is among the most metal-poor damped Ly-alpha systems known and, even though it is observed only ~850 Myr after the big bang, its relative abundances do not show signatures of chemical enrichment by Population III stars.Comment: Updated to match published versio

    Lyα\alpha Halos Around z6z\sim6 Quasars

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    We present deep MUSE observations of five quasars within the first Gyr of the Universe (z6z\gtrsim6), four of which display extended Lyα\alpha halos. After PSF-subtraction, we reveal halos surrounding two quasars for the first time, as well as confirming the presence of two more halos for which tentative detections exist in long-slit spectroscopic observations and narrow-band imaging. The four Lyα\alpha halos presented here are diverse in morphology and size, they each display spatial asymmetry, and none are centred on the position of the quasar. Spectra of the diffuse halos demonstrate that none are dramatically offset in velocity from the systemic redshift of the quasars (Δ\Delta v <200< 200 kms1^{-1}), however each halo shows a broad Lyα\alpha line, with a velocity width of order 1000\sim1000 kms1^{-1}. Total Lyα\alpha luminosities range between \sim 2×10432 \times 10^{43} erg s1^{-1} and \sim 2×10442 \times 10^{44} erg s1^{-1}, reaching maximum radial extents of 133013 - 30 pkpc from the quasar positions. We find larger sizes and higher Lyα\alpha luminosities than previous literature results at this redshift, but find no correlation between the quasar properties and the Lyα\alpha halo, suggesting that the detected emission is most closely related to the physical properties of the circum-galactic mediumComment: 19 pages, Accepted for publication in Ap

    Concomitancia de atipías de mama homolateral

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    La enfermedad de Paget de la mama se expresa clínicamente como placa infiltrada, unlilateral, con eritema y escamas. A pesar de estar descripta su asociación con carcinomas ductales de la misma mama, la imagenología no siempre detecta una o ambas lesiones, siendo la clínica y la citología los elementos de orientación para detectar y confirmar esta patología .El Paget de la mama corresponde al 1-3% de la Patología Mamaria Maligna e incide en la postmenopausia, más precisamente entre la sexta y séptima décadas de la vida femenina. Se han reportado hasta un 71% de informes que no advierten la presencia de atipías no palpables asociadas a Paget.Facultad de Ciencias Médica
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