154 research outputs found

    Modeling the Black Hole Recoil from the Nucleus

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    GEMINI + GMOS and Chandra emission-line spectroscopy reveal that the Fanaroff-Riley II radio-source J133658.3- 295105 is a local object behind the barred-spiral galaxy M83 that is projected onto the galaxy?s disk at about 60" from the galaxy?s optical nucleus. J133658.3-295105 and its radiolobes are aligned with the optical nucleus of M83 and two other radio-sources neither of which are supernova remnants or HII regions. The optical nucleus of M83 is off-centered by 2.7" (~60 pc) with regard to the kinematic center. Its mass is within the range (1 - 4) × 106 Msun and the velocity dispersion at its center points to a non-resolved mass concentration of <~106 Msun. In this paper we study the circumstances in which the radio source would have been ejected from the central region of M83. We analyze different types of collisions of binary and triple systems of super-massive black holes (SMBHs) by numerical simulations using a Post-New- tonian approximation of order 7/2 (~1/c7). We developed an N-body code specially built to numerically integrate the Post-Newtonian equations of motion with a symplectic method. Numerical experiments show that the code is robust enough to handle virtually any mass ratio between particles and to follow the interaction up to a SMBH separation of three Schwarzschild radii. We show that within the current Post-Newtonian approximation, a scenario in which one of the three SMBHs suffers a slingshot-like kick is best suited to explain the ejection of J133658.3-295105, which simultaneously produces the recoil of the remaining BH pair, which drags together a subset of stars from the original cluster forming a structure that mimics the offcenter optical nucleus of M83. The simulation parameters are tuned to reproduce the velocities and positions of J133658.3-295105 as well as the optical nucleus and the putative SMBH at its center.Fil: Ferrari, Guilherme. Instituto de Física. Universidade Federal do Rio Grande do Sul; Brazil;Fil: Dottori, Horacio Alberto. Instituto de Física. Universidade Federal do Rio Grande do Sul; Brazil;Fil: Diaz, Ruben Joaquin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico - Conicet - San Juan. Instituto de Ciencias Astronómicas de la Tierra y del Espacio; Argentina

    Develando con T-ReCS las regiones oscurecidas del núcleo starburst mas cercano

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    Presentamos las imágenes de la región nuclear de NGC 253 obtenidas con el instrumento T-ReCS (Thermal-Region Camera Spectrograph) del telescopio Gemini Sur. Las mismas fueron tomadas en las bandas Qa, Si-2, NeII, y continuo de NeII (18.3, 8.7, 12.8, 13.1 µm respectivamente), con un muestreo espacial medio de 0.2” (3.4 pc). Se identifican y analizan las subestructuras más importantes alrededor de los posibles núcleos y se discuten sus roles en el escenario dinámico de la galaxia.We present the images of the nuclear region of NGC 253 obtained with the T-ReCS instrument (Thermal-Region Camera Spectrograph) of the Gemini South Telescope. Such images were taken in the Qa, Si-2, NeII and NeII continuum bands (18.3, 8.7, 12.8 and 13.1 µm respectively) with an average spatial sampling of 0.2” (3.4 pc). We also identify and analyze the most important sub-structures around the possible nuclei and we discuss their roles in the dynamic scenario of the galaxy.Fil: Camperi, Javier Antonio. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Gunthardt, Guillermo Ivan. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Agüero, Maria Paz. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Diaz, Ruben Joaquin. Gemini Observatory; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Schirmer, M.. Gemini Observatory; Chile. Universitaet Bonn; Alemani

    Cinemática del gas ionizado y perfiles de luminosidad de las Galaxias Porotos Verdes

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    Presentamos aquí los resultados espectroscópicos preliminares sobre una muestra de galaxias porotos verdes (GBG), conocidas por presentar regiones de líneas angostas ultra-luminosas y extendidas a toda escala en la galaxia huésped. Se tomaron espectros en Gemini con GMOS-S,N para obtener cocientes de líneas de emisión, cinemática del gas ionizado y perfiles de luminosidad en distintas bandas de continuo. Reportamos aquí nuevos resultados que confirman que para toda esta muestra de 12 GBG la emisión del [OIII]λ5008 tiene una extensión de 5 a 17 kpc, similar, y en algunos casos superior, a la del continuo estelar. En el caso extremo de J145533.6+044643 la emisión del [OIII] se extiende hasta un diámetro de 17.5±1.6 kpc. Determinamos que los perfiles de emisión de continuo tienen radios de escala de 3 a 7 kpc y son más extensos para longitudes de onda más cortas, lo que es consistente con los radios de escala de galaxias espirales gigantes o sistemas en fusión. Los perfiles de color que determinamos indican la presencia de extinción y posible formación estelar.We present preliminary spectroscopic results of a sample of green bean galaxies (GBG), known to show ultra-luminous, galaxy-wide, narrow-line regions. We analyze Gemini GMOS-S,N spectra of a sample of 12 GBG in order to obtain emission line ratios, gas kinematics and luminosity profiles in some continuous bands. We report here new results that confirm that the [OIII]λ5008 emission extends from 5 to 17 kpc, in all cases scales similar or larger than the stellar continuums at the spectra. In the extreme case of J145533.6+044643 the [OIII] emission reaches a diameter of 17.5±1.6 kpc. We find that the continuum half light radii extend from 3 to 7 kpc, the largest scale radius at shortest wavelengths, which is consistent with the scale lengths of large spiral galaxies or merging systems. Another new result is that the spatial variation of the continuum color profiles indicate the presence of extinction and possibly star formation.Fil: Diaz, Ruben Joaquin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Agüero, Maria Paz. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Schirmer, M.. Observatorio Gemini; Estados Unidos. Universitaet Bonn; AlemaniaFil: Holheim, K.. Observatorio Gemini; Estados UnidosFil: Levenson, N.. Observatorio Gemini; Estados UnidosFil: Winge, C.. Observatorio Gemini; Estados Unido

    A near-infrared view of Nearby Galaxies: The Case of NGC 6300

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    We present a near-infrared study of the Seyfert 2 galaxy NGC 6300, based on subarcsecond images and long slit spectroscopy obtained with Flamingos-2 at Gemini South. We have found that the peak of the nuclear continuum emission in the K s band and the surrounding nuclear disk are 25 pc off-center with respect to the center of symmetry of the larger scale circumnuclear disk, suggesting that this black hole is still not fixed in the galaxy potential well. The molecular gas radial velocity curve yields a central black hole upper mass estimation of . The Paβ emission line has a strongly asymmetric profile with a blueshifted broad component that we associate with a nuclear ionized gas outflow. We have found in the K s -band spectra that the slope of the continuum becomes steeper with increasing radii, which can be explained as the presence of large amounts of hot dust not only in the nucleus but also in the circumnuclear region up to r = 27 pc. In fact, the nuclear red excess obtained after subtracting the stellar contribution resembles to that of a blackbody with temperatures around 1200 K. This evidence supports the idea that absorbing material located around the nucleus, but not close enough to be the torus of the unified model, could be responsible for at least part of the nuclear obscuration in this Seyfert 2 nucleus.Fil: Gaspar, Gaia. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Diaz, Ruben Joaquin. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentina. Gemini Observatory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Observatorio Astronomico de la Universidad Nacional de Cordoba; ArgentinaFil: D'Ambra, A.. Observatorio Astronomico de la Universidad Nacional de Cordoba; ArgentinaFil: Agüero, Maria Paz. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gunthardt, Guillermo Ivan. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentin

    Circumnuclear Rings and Lindblad Resonances in Spiral Galaxies

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    In order to study the location of circumnuclear rings (CNR) and their possible relation with the inner Lindblad res- onances (ILR), we investigate a sample of spiral galaxies. For this purpose, we have obtained and analyzed medium resolution spectra of 5 spiral galaxies in the range 6200 Å to 6900 Å. Through the Hα emission line, we constructed the radial velocity curves, and then the rotation curves. By fitting them, considering two or three components of an axisy- metric Miyamoto−Nagai gravitational potential, we constructed the angular velocity and Lindblad curves. In addition, we determined the CNR radius by using the 2D spectra and generating the Hα spatial emission radial profiles.We determined the position of the resonances and we calculated the angular velocity pattern, which are in the range of 26 − 47 km s−1 kpc−1 for the galaxies of the sample. According to our results, the CNRs are located between the inner ILR (iILR) and the outer ILR (oILR), or between the center of the galaxy and the ILR, when the object has only one of such resonance; in agreement with previous results. In addition, we calculated the dimensionless parameter defined as R = RCR / Rbar, being in the range 1.1 − 1.6, in agreement with previous results found in the literature.Fil: Schmidt, Eduardo Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Mast, Damian. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Diaz, Ruben Joaquin. Gemini Observatory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Agüero, Maria Paz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Gunthardt, Guillermo Ivan. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Gimeno, G.. Gemini Observatory; Estados UnidosFil: Oio, Gabriel Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Gaspar, Gaia. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Virial masses of late-type galaxies from the SDSS DR16

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    Motivated by the challenges of calculating the dynamical masses of late-type galaxies (LTGs) and the enormous amount of data from the Sloan Digital Sky Survey (SDSS), we calculate virial masses of a sample of approximately 126 000 LTGs from the sixteenth data release of the SDSS. The virial mass estimations were made considering Newtonian mechanics, virial equilibrium and velocity dispersion from stars and gas. The procedure gave as a result seven mass estimations for each galaxy. The calculated masses were calibrated using a sample of spiral galaxies with velocity rotation curves. Considering the results from the calibration, we find that the correlation between virial and dynamical (rotation curve) masses is stronger for high inclination values. Therefore, the calibration relies more on the available data for higher inclination angle galaxies. We also show that if we have a heterogeneous sample of galaxies one must take into consideration the size and colour of these galaxies by using the following variables: Sersic index n, concentration index, and colour of the stars. For relatively smaller and bluer LTGs, the gas velocity dispersion provides a more consistent mass calculation, while for LTGs that are relatively larger and redder the stellar velocity dispersion provides a better correlated mass calculation.Fil: Nigoche Netro, A.. Universidad de Guadalajara; México. Instituto de Astronomía y Meteorologia de la Universidad de Guadalajara; MéxicoFil: De La Fuente, E.. Universidad de Guadalajara; México. University of Tokyo; JapónFil: Diaz, Ruben Joaquin. United States Gemini Office; Estados Unidos. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Agüero, Maria Paz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Kemp, S. N.. Instituto de Astronomía y Meteorologia de la Universidad de Guadalajara; MéxicoFil: Marquez Lugo, R. A.. Instituto de Astronomía y Meteorologia de la Universidad de Guadalajara; MéxicoFil: Lagos, P.. Centro de Astrofísica Da Universidade Do Porto; PortugalFil: Ruelas Mayorga, A.. Universidad Nacional Autónoma de México; MéxicoFil: López Contreras, N. L.. Instituto de Astronomía y Meteorologia de la Universidad de Guadalajara; Méxic

    Risk factors for one-year mortality in hospitalized adults with severe covid-19 comment

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    As the body''s immunity declines with age, elderly-hospitalized patients due to COVID-19 might be at higher mortality risk. Therefore, the aim of this prospective study was to examine the possible risk factors (demographic, social or comorbidities) most associated with mortality one-year after diagnosis of COVID-19. Routine data were collected from a cohort of hospitalized adults with severe COVID-19. The primary endpoint was mortality at one-year after diagnosis of COVID-19. We used a Cox proportional hazard model to estimate the hazard ratios (HRs) for both all-cause and specific cardiorespiratory mortality. A fully adjusted model included sex, socioeconomic status, institutionalization status, disability, smoking habit, and comorbidities as confounders. A total of 368 severe cases hospitalized on average 67.3 +/- 15.9 years old were included. Participants aged >= 71 years had significantly higher HRs for all-cause mortality (adjusted HRs = 2.86, 95%CI: 2.01-4.07) and cardiorespiratory mortality (adjusted HRs = 2.86, 95%CI: 1.99-4.12). The association between age and mortality after diagnosis of COVID-19 due to both all-causes and cardiorespiratory mortality showed a consistent dose-response fashion. Institutionalization, disability, and socioeconomic status also showed a significant association with mortality. In conclusion, aging itself was the most important risk factor associated with mortality one year after diagnosis of COVID-19. People with disabilities, institutionalized or low socioeconomic status are significantly more likely to die after COVID-19

    Safety and efficacy of ribociclib plus letrozole in patients with HR+, HER2– advanced breast cancer: Results from the Spanish sub-population of the phase 3b CompLEEment-1 trial

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    Background: Breast cancer is the most common malignancy and the second leading cause of cancer-related mortality in Spanish women. Ribociclib in combination with endocrine therapy (ET) has shown superiority in prolonging survival in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) vs. ET alone.Methods: CompLEEment-1 is a single-arm, open-label phase 3b trial evaluating ribociclib plus letrozole in a broad population of patients with HR+, HER2- ABC. The primary endpoints were safety and tolerability. Here we report data for Spanish patients enrolled in CompLEEment-1.Results: A total of 526 patients were evaluated (median follow-up: 26.97 months). Baseline characteristics showed a diverse population with a median age of 54 years. At study entry, 56.5% of patients had visceral metastases and 8.7% had received prior chemotherapy for advanced disease. Rates of all-grade and Grade >= 3 adverse events (AEs) were 99.0% and 76.2%, respectively; 21.3% of patients experienced a serious AE, and 15.8% of AEs led to treatment discontinuation. AEs of special interest of neutropenia, increased alanine aminotransferase, increased aspartate aminotransferase and QTcF prolongation occurred in 77.8%, 14.8%, 11.4% and 4.0% of patients, respectively. Patients aged >70 years experienced increased rates of all-grade and Grade >= 3 neutropenia and anemia. Efficacy results were consistent with the global study.Conclusions: Results from Spanish patients enrolled in CompLEEment-1 are consistent with global data showing efficacy and a manageable safety profile for ribociclib plus letrozole treatment in patients with HR+, HER2-ABC, including populations of interest (NCT02941926).Trial registration: ClinicalTrials.gov NCT0294192

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to &lt;90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], &gt;300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of &lt;15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P&lt;0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P&lt;0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

    Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

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    Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
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