Merging neutron star and black hole binaries: Inference of their parameters and simulations of their formation and fate

In recent years, the growing numbers of black hole and neutron star merger candidates observed by the Advanced LIGO (Laser Interferometer Gravitational-Wave Observatory) and Virgo gravitational-wave observatories are rapidly expanding the frontiers of astrophysics. The observations enable (i) direct measurements of properties of these compact objects with information extraction from the gravitational-wave data, and seek the understanding of (ii) mechanisms by which the close compact object binaries come into existence and (iii) the astrophysical processes that take place after they merge. This thesis presents work on all these three fronts (i) We present measurements of properties of the binary neutron star and black hole observations from the LIGO-Virgo observatories\u27 second observing run, using Bayesian parameter estimation on the gravitational-wave data. During this observing run, LIGO-Virgo for the first time reported observations of gravitational waves from a binary neutron star inspiral, GW170817. This same source was also observed across the full electromagnetic spectrum. We combine gravitational-wave observations with a physical constraint on the component stars\u27 equation of state and information from electromagnetic observations, to measure tidal deformabilities and radii of the neutron stars in the source binary. (ii) We explore the ``common envelope\u27\u27 phase in the lives of binary stars in our universe. Common envelope is proposed to be the most probable mechanism of assembly of close compact object binaries. We present three-dimensional hydrodynamic simulations to model these episodes and discuss our understanding of the effect of this phase on the observable properties---such as masses and spins---of LIGO-Virgo\u27s stellar mass black hole populations. (iii) We discuss the aftermath of compact object mergers where at least one of the components is a neutron star. We use three-dimensional General Relativistic Magnetohydrodynamic simulations to model one of the typical outcomes---black hole surrounded by matter in the form of an accretion disk---for a variety of merger scenarios. We present connections of the binary parameters to properties of the disks, and the nucleosythetic yields they produce. Using the simulation results, we predict properties of kilonova emissions from future neutron star mergers

Constraining the neutron-matter equation of state with gravitational waves

We show how observations of gravitational waves from binary neutron star (BNS) mergers over the next few years can be combined with insights from nuclear physics to obtain useful constraints on the equation of state (EoS) of dense matter, in particular, constraining the neutron-matter EoS to within 20% between one and two times the nuclear saturation density $n_0\approx 0.16\ {\text{fm}^{-3}}$. Using Fisher information methods, we combine observational constraints from simulated BNS merger events drawn from various population models with independent measurements of the neutron star radii expected from x-ray astronomy (the Neutron Star Interior Composition Explorer (NICER) observations in particular) to directly constrain nuclear physics parameters. To parameterize the nuclear EoS, we use a different approach, expanding from pure nuclear matter rather than from symmetric nuclear matter to make use of recent quantum Monte Carlo (QMC) calculations. This method eschews the need to invoke the so-called parabolic approximation to extrapolate from symmetric nuclear matter, allowing us to directly constrain the neutron-matter EoS. Using a principal component analysis, we identify the combination of parameters most tightly constrained by observational data. We discuss sensitivity to various effects such as different component masses through population-model sensitivity, phase transitions in the core EoS, and large deviations from the central parameter values.Comment: 13 pages, 9 figures + supplement 11 page

Posterior samples of the parameters of binary black holes from Advanced LIGO, Virgo's second observing run

This paper presents a parameter estimation analysis of the seven binary black hole mergers-GW170104, GW170608, GW170729, GW170809, GW170814, GW170818, and GW170823-detected during the second observing run of the Advanced LIGO and Virgo observatories using the gravitational-wave open data. We describe the methodology for parameter estimation of compact binaries using gravitational-wave data, and we present the posterior distributions of the inferred astrophysical parameters. We release our samples of the posterior probability density function with tutorials on using and replicating our results presented in this paper

Actividad del extracto etanólico de las hojas de Machaerium floribundum contra bacterias que inducen el acné y su efecto citoprotector y antioxidante sobre fibroblastos

Propionibacterium acnes, Staphylococcus epidermidis and Staphylococcus aureus have been recognized as the bacteria that are involved in the inflammatory process of acne, while oxidants and antioxidants are involved in the repair of cutaneous tissue affected. In this study an evaluation was made of the antibacterial effect by the agar diffusion and broth dilution method, the cytoprotective and antioxidant effect on 3T3 dermic fibroblast cells, treated with hydrogen peroxide and the scavenging capacity of free radicals was determined by the 2, 2-diphenyl-l-picrylhydrazyl (DPPH) method as well as the Reducing Power of the ethanolic extracts of the leaves of the Machaerium floribundum. Minimal bactericidal concentrations (MBC) were obtained against Propionibacterium acnes and Staphylococcus aureus of 5 mg/mL and 2 mg/mL, respectively. A cytoprotective effect of 111% was observed over the cellular viability of the fibroblasts at 10 μg/mL and an antioxidant effect of 92% over the viability of the fibroblasts treated with hydrogen peroxide at 25 μg/mL. A stimulation of 24% growth of fibroblasts at 50 μg/mL was evidenced. On the other hand a 93% scavenging activity of the DPPH free radical was shown for 100 μg/mL with a CI50 of 34 μg/mL. The reducing power was evidenced to be dependent on the concentration. The results obtained indicated that the ethanolic extract of Machaerium floribundum shows a good antibacterial activity against bacteria that induce acne and a high potential for scavenging of free radicals at relatively low concentrations.Propionibacterium acnes, Staphylococcus epidermidis y Staphylococcus aureus han sido reconocidas como las bacterias involucradas en el proceso inflamatorio del acné, mientras que oxidantes y antioxidantes han sido implicados en la reparación del tejido cutáneo afectado. El presente estudio evaluó el efecto antibacteriano por el método de difusión en agar y dilución en caldo; el efecto citoprotector y antioxidante sobre células de fibroblastos dérmicos 3T3, tratadas con peróxido de hidrogeno; se determinó la capacidad secuestrante de radicales libres por el método del 2,2-difenil-2-picrihidracil (DPPH) y el poder reductor de los extractos etanólicos de las hojas de Machaerium floribundum. El extracto mostro una CMB de 5mg/mL y 2mg/mL para P. acnes y S. aureus, respectivamente. Se observó un efecto citoprotector sobre la viabilidad celular de los fibroblastos de 111% a 10 μg/mL y antioxidante mostrado sobre la viabilidad de los fibroblastos tratados con peróxido de hidrogeno de 92% a 25 μg/mL. Se evidencio estimulación del crecimiento de fibroblastos de 24% a 50 μg/mL. Por otra parte se mostró actividad secuestrante del radical libre DPPH de 93% a 100 μg/mL, con una CI50 34 μg/ mL. El poder reductor evidencio ser dependiente de la concentración. Los resultados indicaron que el extracto etanólico de Machaerium floribundum presenta una buena actividad antibacteriana contra las bacterias que inducen el acné y un alto potencial secuestrante de radicales libres a concentraciones relativamente bajas

Stringent constraints on neutron-star radii from multimessenger observations and nuclear theory

The properties of neutron stars are determined by the nature of the matter that they contain. These properties can be constrained by measurements of the star's size. We obtain stringent constraints on neutron-star radii by combining multimessenger observations of the binary neutron-star merger GW170817 with nuclear theory that best accounts for density-dependent uncertainties in the equation of state. We construct equations of state constrained by chiral effective field theory and marginalize over these using the gravitational-wave observations. Combining this with the electromagnetic observations of the merger remnant that imply the presence of a short-lived hyper-massive neutron star, we find that the radius of a $1.4\,\rm{M}_\odot$ neutron star is $R_{1.4\,\mathrm{M}_\odot} = 11.0^{+0.9}_{-0.6}~{\rm km}$ (90% credible interval). Using this constraint, we show that neutron stars are unlikely to be disrupted in neutron-star black-hole mergers; subsequently, such events will not produce observable electromagnetic emission.Comment: 39 pages, 4 figure

High-Precision Inversion of Dynamic Radiography Using Hydrodynamic Features

Radiography is often used to probe complex, evolving density fields in dynamic systems and in so doing gain insight into the underlying physics. This technique has been used in numerous fields including materials science, shock physics, inertial confinement fusion, and other national security applications. In many of these applications, however, complications resulting from noise, scatter, complex beam dynamics, etc. prevent the reconstruction of density from being accurate enough to identify the underlying physics with sufficient confidence. As such, density reconstruction from static/dynamic radiography has typically been limited to identifying discontinuous features such as cracks and voids in a number of these applications. In this work, we propose a fundamentally new approach to reconstructing density from a temporal sequence of radiographic images. Using only the robust features identifiable in radiographs, we combine them with the underlying hydrodynamic equations of motion using a machine learning approach, namely, conditional generative adversarial networks (cGAN), to determine the density fields from a dynamic sequence of radiographs. Next, we seek to further enhance the hydrodynamic consistency of the ML-based density reconstruction through a process of parameter estimation and projection onto a hydrodynamic manifold. In this context, we note that the distance from the hydrodynamic manifold given by the training data to the test data in the parameter space considered both serves as a diagnostic of the robustness of the predictions and serves to augment the training database, with the expectation that the latter will further reduce future density reconstruction errors. Finally, we demonstrate the ability of this method to outperform a traditional radiographic reconstruction in capturing allowable hydrodynamic paths even when relatively small amounts of scatter are present.Comment: Submitted to Optics Expres

Comparative Extraction of Phenolic Compounds from Olive Leaves Using a Sonotrode and an Ultrasonic Bath and the Evaluation of Both Antioxidant and Antimicrobial Activity

This study is part of the project SHEALTHY that has received funding from European Union's Horizon 2020 Research and Innovation Programme under grant agreement No 817936. This study was also supported by project RTI2018-099835-A-I00 financed by MCIN/AEI/10.13039/5011000 11033/FEDER "Una manera de hacer Europa".A sonotrode ultrasound-assisted extraction of phenolic compounds from olive leaves has been developed using a Box-Behnken design to optimize the effects of solvent composition and ultrasound parameters. The determination of single phenolic compounds was performed by HPLC-MS and the highest recovery in total compounds, oleuropein and hydroxytyrosol was achieved using EtOH/H2O (55:45, v/v), 8 min and 100% of amplitude. The optimal conditions were applied on leaves from seven olive cultivars grown under the same conditions and the results were compared with those found by using a conventional ultrasonic bath, obtaining no statistical differences. Moreover, antioxidant activity by FRAP, DPPH and ABTS in these olive leaf extracts was evaluated and they exhibited a significant correlation with oleuropein and total phenolic content. All cultivars of olive leaf extracts were found to be active against S. aureus and methicillin-resistant S. aureus with minimum bactericidal concentration (MBC) values) that ranged from 5.5 to 22.5 mg mL(-1). No extracts showed antimicrobial activity against C. albicans. The percentages of mycelium reduction in B. cinerea ranged from 2.2 and 18.1%. Therefore, sonotrode could be considered as an efficient and fast extraction technique that could be easily scaled-up at industrial level, thus allowing for olive leaves to be revalorized.European Union's Horizon 2020 Research and Innovation Programme 817936MCIN/AEI/FEDER "Una manera de hacer Europa" RTI2018-099835-A-I0

Effect of Lactic Acid Bacteria Fermentation on the Polar Compounds Content with Antioxidant and Antidiabetic Activity of Avocado Seed Extracts

Avocado seeds, a common waste in the avocado processing industry, have been found to have several bioactivities, such as anticancer, antimicrobial, hypocholesterolemic, antioxidant, and antidiabetic activities, among others. Nowadays, this wastage is causing an environmental problem, so the use of new technologies to take advantage of it is a novel field of research. In this study, the submerged fermentation by lactic acid bacteria was used as a novel tool for improving the bioactive compound extraction from avocado seeds. Avocado seeds were fermented by different strains, their polar compounds were identified and quantified by HPLC-ESI-TOF-MS, the antioxidant activity was measured by DPPH and FRAP assays, and the antidiabetic activity was analyzed by the alpha-amylase assay. A total of 32 polar compounds were identified, with 13 of them being described in avocado seeds for the first time. Avocado seeds fermented by Pentosaceus acidilactici showed the highest sum of polar compounds (6279.63 67.74 g/g d.w.), and by extension, of hydroxytyrosol glucoside (2989.76 3.64 g/g d.w.). Lactiplantibacillus plantarum CECT 9567 showed the highest antioxidant activity measured by both DPPH and FRAP assays (6294.67 19.44 and 6846.91 2.13 g TE/g d.w., respectively). Furthermore, Lactiplantibacillus plantarum CECT 748T had the highest antidiabetic activity (52.15% 0.67% inhibition of alpha-amylase activity), attributable to the polyphenols. According to the results, submerged fermentation by lactic acid bacteria led to an interesting increase of the polar compounds’ extractability of avocado seeds, consequently improving the bioactivities of the extracts, which could then be used for food nutraceutical or cosmetic purposes.Project RTI2018-099835-A-I00MCIN/AEI/ 10.13039/501100011033/FEDER, “Una manera de hacer Europ