Análisis de grupos compactos de galaxias mediante lentes gravitacionales débiles

Tesis (Doctor en Astronomía)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía, Física y Computación, 2020.Fil: Chalela García, Martín. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía, Física y Computación; Argentina.La tesis presenta un análisis sobre Grupos Compactos de galaxias utilizando el fenómeno de lentes gravitacionales débiles como herramienta de estudio. Se determina el centro de potencial gravitacional y se estudia la contaminación debido a galaxias falsamente clasificadas como miembros. También se discuten resultados sobre la dependencia de la señal de lente débil en función del redshift. En la primera sección se introduce el marco teórico sobre Grupos Compactos y el fenómeno de lentes gravitacionales. En la segunda parte se describe el catálogo de Grupos Compactos utilizado en el análisis y se realiza un análisis variacional de la señal de lente gravitacional débil según los parámetros que caracterizan a los Grupos Compactos. Se encontró una correlación entre el contenido morfológico de los sistemas y la intensidad de la señal de lente débil, indicando una posible contaminación por falsos miembros. En la última sección se aborda un estudio basado en la combinación de tres catálogos de lentes débiles de alta calidad fotométrica para explorar con mayor precisión la dependencia de la señal de lente de los Grupos Compactos en función del redshift.The thesis presents an analysis on Compact Groups of galaxies using the weak gravitational lensing phenomenon as a tool for study. The determination of the center of the gravitational potential and a study on contamination due to falsely classified galaxies as members are among the main contributions. Additionally, results are discussed on the dependence of the weak lensing signal of Compact Groups as a function of redshift. The first section introduces the theoretical framework on Compact Groups and the gravitational lensing phenomenon. The second part describes the catalog of Compact Groups used in the analysis and performs a variational analysis of the weak gravitational lensing signal according to the parameters that characterize the Compact Groups. A correlation was found between the morphological content of the systems and the intensity of the weak lensing signal, indicating possible contamination by interlopers. Finally, a study is carried out based on the combination of three high-quality photometric weak lensing catalogs to explore with greater precision the dependence of the lensing signal of Compact Groups as a function of redshift.Fil: Chalela García, Martín. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía, Física y Computación; Argentina

NIRDust: Probing Hot Dust Emission Around Type 2 AGN Using K-band Spectra

Hot dust in the proximity of AGNs strongly emits in the Near Infrared producing a red excess that, in type 2 sources, can be modeled to measure its temperature. In the era of high spatial-resolution multi-wavelength data, mapping the hot dust around Supermassive Black Holes is important for the efforts to achieve a complete picture of the dust role and distribution around these compact objects. In this work we propose a methodology to detect the hot dust emission in the proximity of Type 2 AGNs and measure its temperature using K-band spectra ($\lambda_c$ = 2.2\,$\mu$m). To achieve this, we have developed NIRDust, a Python package for modeling K-band spectra, estimate the dust temperature and characterize the involved uncertainties. We tested synthetic and real spectra in order to check the performance and suitability of the physical model over different types of data. Our tests on synthetic spectra demonstrated that the obtained results are influenced by the signal-to-noise ratio (S/N) of the input spectra. However, we accurately characterized the uncertainties, which remained below $\sim$150 K for an average S/N per pixel exceeding 20. Applying NIRDust to NGC 5128 (Centaurus A), observed with the Gemini South Telescope, we estimated a dust temperature of 662 and 667 K from Flamingos-2 spectra and 697 and 607 K from GNIRS spectra using two different approaches.Comment: 12 pages, 7 figure

On the weak lensing masses of a new sample of galaxy groups

Galaxy group masses are important to relate these systems with the dark matter halo hosts. However, deriving accurate mass estimates is particularly challenging for low-mass galaxy groups. Moreover, calibration of observational mass-proxies using weak-lensing estimates have been mainly focused on massive clusters. We present here a study of halo masses for a sample of galaxy groups identified according to a spectroscopic catalogue, spanning a wide mass range. The main motivation of our analysis is to assess mass estimates provided by the galaxy group catalogue derived through an abundance matching luminosity technique. We derive total halo mass estimates according to a stacking weak-lensing analysis. Our study allows to test the accuracy of mass estimates based on this technique as a proxy for the halo masses of large group samples. Lensing profiles are computed combining the groups in different bins of abundance matching mass, richness, and redshift. Fitted lensing masses correlate with the masses obtained from abundance matching. However, when considering groups in the low-and intermediate-mass ranges, masses computed according to the characteristic group luminosity tend to predict higher values than the determined by the weak-lensing analysis. The agreement improves for the low-mass range if the groups selected have a central early-Type galaxy. Presented results validate the use of mass estimates based on abundance matching techniques, which provide good proxies to the halo host mass in a wide mass range.Fil: Gonzalez, Elizabeth Johana. 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; Argentina. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Rodriguez, Facundo. 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: Merchan, Manuel Enrique. 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: Garcia Lambas, Diego Rodolfo. 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: Makler, Martín. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Centro Internacional de Estudios Avanzados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias Físicas. - Universidad Nacional de San Martín. Instituto de Ciencias Físicas; Argentina. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Chalela, Martín. 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: Pereira, Maria E. S.. University of Michigan. Department of Physics; Estados UnidosFil: Moraes, Bruno. Universidade Federal do Rio de Janeiro; BrasilFil: Shan, HuanYuan. Chinese Academy of Sciences; República de China. Shanghai Astronomical Observatory; Chin

Compact Groups analysis using weak gravitational lensing II: CFHT Stripe 82 data

In this work we present a lensing study of Compact Groups (CGs) using data obtained from the high-quality Canada-France-Hawaii Telescope Stripe 82 Survey. Using stacking techniques we obtain the average density contrast profile. We analyse the lensing signal dependence on the groups' surface brightness and morphological content, for CGs in the redshift range z = 0.2-0.4.We obtain a larger lensing signal for CGs with higher surface brightness, probably due to their lower contamination by interlopers. Also, we find a strong dependence of the lensing signal on the group concentration parameter, with the most concentrated quintile showing a significant lensing signal, consistent with an isothermal sphere with σV = 336 ± 28 km s-1 and a NFW profile with R200 = 0.60 ± 0.05 h-1 70 Mpc. We also compare lensing results with dynamical estimates finding a good agreement with lensing determinations for CGs with higher surface brightness and higher concentration indexes. On the other hand, CGs that are more contaminated by interlopers show larger dynamical dispersions, since interlopers bias dynamical estimates to larger values, although the lensing signal is weakened.Fil: Chalela Garcia, Martin. 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: Gonzalez, Elizabeth Johana. 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: Makler, Martín. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Garcia Lambas, Diego Rodolfo. 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: Pereira, Maria E.S.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: O'Mill, Ana Laura. Instituto de Astronomia Teorica y Experimental; ArgentinaFil: Shan, Huan Yuan. Argelander-Institut fur Astronomie; Alemani

Impact of high-flow oxygen therapy during exercise in idiopathic pulmonary fibrosis: a pilot crossover clinical trial

[Background] Supplemental oxygen delivered with standard oxygen therapy (SOT) improves exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). Although high-flow nasal cannula oxygen therapy (HFNC) improves oxygenation in other respiratory diseases, its impact on exercise performance has never been evaluated in IPF patients. We hypothesized that HFNC may improve exercise capacity in IPF subjects compared to SOT.[Methods] This was a prospective, crossover, pilot randomized trial that compared both oxygenation methods during a constant submaximal cardiopulmonary exercise test (CPET) in IPF patients with exertional oxygen saturation (SpO2) ≤ 85% in the 6-min walking test. The primary outcome was endurance time (Tlim). Secondary outcomes were muscle oxygen saturation (StO2) and respiratory and leg symptoms.[Results] Ten IPF patients [71.7 (6) years old, 90% males] were included. FVC and DLCO were 58 ± 11% and 31 ± 13% pred. respectively. Tlim during CPET was significantly greater using HFNC compared to SOT [494 ± 173 vs. 381 ± 137 s, p = 0.01]. HFNC also associated with a higher increase in inspiratory capacity (IC) [19.4 ± 14.2 vs. 7.1 ± 8.9%, respectively; p = 0.04], and a similar trend was observed in StO2 during exercise. No differences were found in respiratory or leg symptoms between the two oxygen devices.[Conclusions] This is the first study demonstrating that HFNC oxygen therapy improves exercise tolerance better than SOT in IPF patients with exertional desaturation. This might be explained by changes in ventilatory mechanics and muscle oxygenation. Further and larger studies are needed to confirm the benefits of HFNC in IPF patients and its potential usefulness in rehabilitation programs.This study has been funded by SEPAR 2017 (Fellowship) and Rio Hortega; ISCIII (Project and fellowship).Peer reviewe

Measuring the surface mass density ellipticity of redMaPPer galaxy clusters using weak lensing

In this work, we study the shape of the projected surface mass density distribution of galaxy clusters using weak-lensing stacking techniques. In particular, we constrain the average aligned component of the projected ellipticity, for a sample of redMaPPer clusters (0.1 ≤ z < 0.4). We consider six different proxies for the cluster orientation and measure for three ranges of projected distances from the cluster centres. The mass distribution in the inner region (up to 700 kpc) is better traced by the cluster galaxies with a higher membership probability, while the outer region (from 700 kpc up to 5 Mpc) is better traced by the inclusion of less probable galaxy cluster members. The fitted ellipticity in the inner region is = 0.21 ± 0.04, in agreement with previous estimates. We also study the relation between and the cluster mean redshift and richness. By splitting the sample in two redshift ranges according to the median redshift, we obtain larger values for clusters at higher redshifts, consistent with the expectation from simulations. In addition, we obtain higher ellipticity values in the outer region of clusters at low redshifts. We discuss several systematic effects that might affect the measured lensing ellipticities and their relation to the derived ellipticity of the mass distribution.Fil: Gonzalez, Elizabeth Johana. 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: Makler, Martín. 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; Argentina. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Garcia Lambas, Diego Rodolfo. 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: Chalela, Martín. Centro Brasileiro de Pesquisas Físicas; Brasil. 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: Pereira, Maria E. S.. Brandeis University; Estados Unidos. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Van Waerbeke, Ludovic. University of British Columbia; CanadáFil: Shan, Huanyuan. Shanghai Astronomical Observatory; China. University of Chinese Academy of Sciences; ChinaFil: Erben, Thomas. Argelander-Institut für Astronomie; Alemani

EGFR and KRAS mutations in lung parenchyma of subjects with EGFR/KRAS wild-type lung adenocarcinoma

The acquisition of driver mutations in non-tumoral cells appears to be very important during the carcinogenesis of adenocarcinoma (ADC). Recent studies suggest that cancer-related mutations may not necessarily be present only in malignant cells, but also in histologically "healthy cells". Objective: to demonstrate the presence of EGFR or KRAS mutations in non-tumoral lung cells in subjects with ADC and negative mutational status. Results: mutations in EGFR or KRAS oncogenes were identified in the normal lung in 9.7% of the subjects. Exon 21 substitution L858R in EGFR was detected in two cases while the exon 19 deletion E746-A750 in the EGFR, the G12C and G12D substitutions in the KRAS were detected once. One patient presented three different mutations in the normal lung parenchyma (EGFR_L858R, KRAS_G12C and KRAS_G12D). The negative-mutation status of the tumor and the mutations detected in the "normal lung" were confirmed using highly sensitive and specific TaqMan PCR (CAST-PCR). No differences were found in terms of progression, progression-free survival or overall survival during the 18 months follow-up. Conclusions: These results confirm the presence of driver mutations in the histologically normal lung parenchyma cells in the absence of mutations coexisting with the primary tumor

Impact of high-flow oxygen therapy during exercise in idiopathic pulmonary fibrosis: a pilot crossover clinical trial

Background: Supplemental oxygen delivered with standard oxygen therapy (SOT) improves exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). Although high-flow nasal cannula oxygen therapy (HFNC) improves oxygenation in other respiratory diseases, its impact on exercise performance has never been evaluated in IPF patients. We hypothesized that HFNC may improve exercise capacity in IPF subjects compared to SOT. Methods: This was a prospective, crossover, pilot randomized trial that compared both oxygenation methods during a constant submaximal cardiopulmonary exercise test (CPET) in IPF patients with exertional oxygen saturation (SpO2) ≤ 85% in the 6-min walking test. The primary outcome was endurance time (Tlim). Secondary outcomes were muscle oxygen saturation (StO2) and respiratory and leg symptoms. Results: Ten IPF patients [71.7 (6) years old, 90% males] were included. FVC and DLCO were 58 ± 11% and 31 ± 13% pred. respectively. Tlim during CPET was significantly greater using HFNC compared to SOT [494 ± 173 vs. 381 ± 137 s, p = 0.01]. HFNC also associated with a higher increase in inspiratory capacity (IC) [19.4 ± 14.2 vs. 7.1 ± 8.9%, respectively; p = 0.04], and a similar trend was observed in StO2 during exercise. No differences were found in respiratory or leg symptoms between the two oxygen devices. Conclusions: This is the first study demonstrating that HFNC oxygen therapy improves exercise tolerance better than SOT in IPF patients with exertional desaturation. This might be explained by changes in ventilatory mechanics and muscle oxygenation. Further and larger studies are needed to confirm the benefits of HFNC in IPF patients and its potential usefulness in rehabilitation programs