134 research outputs found
Clustering of binary black hole mergers: a detailed analysis of the EAGLE+MOBSE simulation
No full textWe perform a detailed study of the cosmological bias of gravitational gave
(GW) events produced by binary black hole mergers (BBHM). We start from a BBHM
distribution modeled inside the EAGLE hydrodyamical simulation using the
population synthesis code MOBSE. We then compare our findings with predictions
from different Halo Occupation Distribution (HOD) prescriptions and find
overall agreement, provided that the modeled properties of host galaxies and
halos in the semi-analytical treatment match those in the simulations. By
highlighting the sources of these discrepancies, we provide the stepping stone
to build future more robust models that prevent the shortcoming of both
simulation-based and analytical models. Finally, we train a neural network to
build a simulation-based HOD and perform feature importance analysis to gain
intuition on which host halo/galaxy parameters are the most relevant in
determining the actual distribution and power spectrum of BBHM. We find that
the distribution of BBHM in a galaxy does not only depend on its size, star
formation rate and metallicity, but also by its kinetic state
Mass and Rate of Hierarchical Black Hole Mergers in Young, Globular and Nuclear Star Clusters
No full textHierarchical mergers are one of the distinctive signatures of binary black hole (BBH) formation through dynamical evolution. Here, we present a fast semi-analytic approach to simulate hierarchical mergers in nuclear star clusters (NSCs), globular clusters (GCs) and young star clusters (YSCs). Hierarchical mergers are more common in NSCs than they are in both GCs and YSCs because of the different escape velocity. The mass distribution of hierarchical BBHs strongly depends on the properties of first-generation BBHs, such as their progenitor’s metallicity. In our fiducial model, we form black holes (BHs) with masses up to ∼103 M⊙ in NSCs and up to ∼102 M⊙ in both GCs and YSCs. When escape velocities in excess of 100 km s−1 are considered, BHs with mass >103 M⊙ are allowed to form in NSCs. Hierarchical mergers lead to the formation of BHs in the pair instability mass gap and intermediate-mass BHs, but only in metal-poor environments. The local BBH merger rate in our models ranges from ∼10 to ∼60 Gpc−3 yr−1; hierarchical BBHs in NSCs account for ∼10−2–0.2 Gpc−3 yr−1, with a strong upper limit of ∼10 Gpc−3 yr−1. When comparing our models with the second gravitational-wave transient catalog, we find that multiple formation channels are favored to reproduce the observed BBH population
Stellar feedback from black-hole high-mass X-ray binaries in galaxy formation models
No full textIn recent years, many works have suggested the role of black-hole high-mass X-ray binaries (BH-HMXB) as potential sources of heating and re-ionization in the interstellar and intergalactic medium. Furthermore, because of the suggested increase of their production rate and X-ray luminosity with decreasing metallicity, BH-HMXBs could be relevant to explain the thermal and ionization history of the Universe at its early stages. As observations indicate, a meaningful amount of the energy released by these sources could be deposited in the local interstellar medium, suggesting that BH-HMXB could modify star forming regions on the host galaxy. In this work, we study the kinetic BH-HMXB feedback using hydrodynamical cosmological simulations which also include SNe feedback. Our preliminary results suggest that BH-HMBXs feedback is not efficient at modifying the star formation activity. However, due the complexity of the problem and the wide dynamical range needed to describe properly different physical events, there are still different schemes to explore. In the future, we will study the role of BH-HMXBs in high numerical resolution simulations at high redshifts, and how the energy is released into the interstellar medium.Fil: Artale, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Tissera, Patricia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Pellizza González, Leonardo Javier. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaXIV Latin American Regional IAU MeetingFlorianópolisBrasilUniversidade Federal de Santa Catarin
Alignment of the central galaxies with the environment
No full textIn this work, we combine ellipticity and major axis position angle measurements from the Sloan Digital Sky Server Data Release 16 with the group finder algorithm of Rodriguez & Merchan to determine the alignment of the central galaxies with the surrounding structures and satellite galaxies lying in their group. We use two independent methods: a modified version of the two- point cross-correlation function and the angle between the central galaxy orientation and the satellite galaxies relative position. The first method allows us to study the inner and outer regions of the cluster, while the second method provides information within the haloes. Our results show that central galaxies present anisotropy in the correlation function up to ∼10 h -1 Mpc , which becomes ∼10 per cent stronger for the brightest ones ( 0.1 M r < -21.5). When we split the galaxy sample by colour, we find that red central galaxies are the main contributors to this anisotropy. We also show that this behaviour does not depend on the group mass or central galaxy ellipticity . Finally , our results are in agreement with previous findings, showing that the two-point cross-correlation function is a good tracer of the galaxy alignments using all galaxies and not only those of the group to which it belongs. In addition, this feature allows us to explore the behaviour of the alignment on larger scales.Fil: 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: Artale, Maria Celeste. 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. Università di Padova; Italia. Istituto Nazionale di Fisica Nucleare; Itali
Anisotropic correlation functions as tracers of central galaxy alignments in simulations
No full textMotivated by observational results, we use IllustrisTNG hydrodynamical numerical simulations to study the alignment of the central galaxies in groups with the surrounding structures. This approach allows us to analyse galaxy and group properties not available in observations. To perform this analysis, we use a modified version of the two-point cross-correlation function and a measure of the angle between the semimajor axes of the central galaxies and the larger structures. Overall, our results reproduce observational ones, as we find large-scale anisotropy, which is dominated by the red central galaxies. In addition, the latter is noticeably more aligned with their group than the blue ones. In contrast to the observations, we find a strong dependence of the anisotropy on the central galaxy with mass, probably associated with the inability of observational methods to determine them. This result allows us to link the alignment to the process of halo assembly and the well-known dependence of halo anisotropy on mass. When we include the dark matter distribution in our analysis, we conclude that the galaxy alignment found in simulations (and observations) can be explained by a combination of physical processes at different scales: the central galaxy aligns with the dark matter halo it inhabits, and this, in turn, aligns with the surrounding structures at large scales.Fil: 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; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; 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; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Artale, Maria Celeste. Universidad Andrés Bello; Chile. Università di Padova; Italia. Istituto Nazionale di Fisica Nucleare; Italia. Purdue University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Andrews, Moira. Purdue University; Estados Unidos. Universidad Nacional de Cordoba. Facultad de Ciencias de la Comunicación.; Argentin
Stellar feedback from high-mass X-ray binaries in cosmological hydrodynamical simulations
No full textWe explored the role of X-ray binaries composed by a black hole and a massive stellar companion [black hole X-ray binaries (BHXs)] as sources of kinetic feedback by using hydrodynamical cosmological simulations. Following previous results, our BHX model selects metal-poor stars (Z = [0, 10−4]) as possible progenitors. The model that better reproduces observations assumes that an ∼20 per cent fraction of low-metallicity black holes are in binary systems which produces BHXs. These sources are estimated to deposit ∼1052 erg of kinetic energy per event. With these parameters and in the simulated volume, we find that the energy injected by BHXs represents ∼30 per cent of the total energy released by Type II supernova and
BHX events at redshift z ∼ 7 and then decreases rapidly as baryons get chemically enriched. Haloes with virial masses smaller than ∼1010 M (or Tvir 105 K) are the most directly affected ones by BHX feedback. These haloes host galaxies with stellar masses in the range 107–108 M. Our results show that BHX feedback is able to keep the interstellar medium warm, without removing a significant gas fraction, in agreement with previous analytical calculations. Consequently, the stellar-to-dark matter mass ratio is better reproduced at high redshift. Our model also predicts a stronger evolution of the number of galaxies as a function of the stellar mass with redshift when BHX feedback is considered. These findings support previous claims that the BHXs could be an effective source of feedback in early stages of galaxy evolution.Fil: Artale, Maria Celeste. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Tissera, Patricia Beatriz. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Pellizza González, Leonardo Javier. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomia; Argentin
A loucura como crítica ao patriarcado em Celeste de Maria Benedita Bormann
No full textEste artigo analisa o romance Celeste (1893), de Maria Benedita Bormann (Délia), com foco na representação da loucura como crítica social ao patriarcado vigente no Brasil do século XIX. A pesquisa propõe uma reavaliação da obra à luz da teoria foucaultiana sobre a loucura enquanto construção social, articulada às normas morais e de gênero impostas às mulheres. A análise busca compreender como a instabilidade psíquica da protagonista encena simbolicamente a ruptura com os padrões idealizados de feminilidade, funcionando como um dispositivo de resistência aos modelos hegemônicos de subjetividade. Considerando o contexto da época em que o romance se passa e a emergência do discurso médico e jurídico sobre o corpo feminino, o artigo destaca como a marginalização da autora e de sua personagem revela a tensão entre desejo e repressão. A leitura crítica propõe, assim, resgatar a relevância de Celeste como uma obra literária que desafia os limites do aceitável em sua época, tanto em termos de forma quanto de conteúdo, reposicionando Maria Benedita Bormann no panorama da literatura brasileira oitocentista.This article analyzes the novel Celeste (1893) by Maria Benedita Bormann (Délia), focusing on the representation of madness as a social critique of the prevailing patriarchy in 19th-century Brazil. The research proposes a reevaluation of the work in light of Foucaultian theory on madness as a social construct, articulated with the moral and gender norms imposed on women. The analysis seeks to understand how the protagonist\u27s psychic instability symbolically stages a rupture with idealized standards of femininity, functioning as a device of resistance to hegemonic models of subjectivity. Considering the context of the time in which the novel is set and the emergence of medical and legal discourse on the female body, the article highlights how the marginalization of the author and her character reveals the tension between desire and repression. The critical reading thus proposes to rescue the relevance of Celeste as a literary work that challenged the limits of the acceptable in its time, both in terms of form and content, repositioning Maria Benedita Bormann in the panorama of 19th-century Brazilian literature
The galaxy size – halo mass scaling relations and clustering properties of central and satellite galaxies
No full textIn this work, we combine size and stellar mass measurements from the Sloan Digital Sky Server (SDSS) with the group finder algorithm of Rodriguez & Merchán in order to determine the stellar and halo mass-size relations of central and satellite galaxies separately. We show that, while central and satellite galaxies display similar stellar mass-size relations, their halo mass-size relations differ significantly. As expected, more massive haloes tend to host larger central galaxies. However, the size of satellite galaxies depends only slightly on halo virial mass. We show that these results are compatible with a remarkably simple model in which the size of central and satellite galaxies scales as the cubic root of their host halo mass, with the normalization for satellites being ∼30 per cent smaller than that for central galaxies, which can be attributed to tidal stripping. We further check that our measurements are in excellent agreement with predictions from the IllustrisTNG hydrodynamical simulation. In the second part of this paper, we analyse how the clustering properties of central and satellite galaxies depend on their size. We demonstrate that, independently of the stellar mass threshold adopted, smaller galaxies are more tightly clustered than larger galaxies when either the entire sample or only satellites are considered. The opposite trend is observed on large scales when the size split is performed for the central galaxies alone. Our results place significant constraints for halo-galaxy connection models that link galaxy size with the properties of their hosting haloes.Fil: 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: Montero Dorta, Antonio D.. Universidade de Sao Paulo; Brasil. Universidad Técnica Federico Santa María; ChileFil: Angulo, Raul E.. Ikerbasque, Basque Foundation For Science; España. Donostia International Physics Center; EspañaFil: Artale, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Innsbruck; AustriaFil: 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; Argentin
Baryons Shaping Dark Matter Haloes
No full textIn this work we aim at investigating the effects of baryons on the dark matter (DM) haloes structure, focusing on the correlation between the presence and importance of stellar discs and the halo shapes. We study the properties of a subsample of DM haloes from Fenix and eagle cosmological simulations. We inspect the central regions of haloes in the mass range [10.9 − 992.3] × 1010 M at z = 0, comparing the hydrodynamic runs and their dark matter only (DMo) counterparts. Our results indicate that baryons have a significant impact on the shape of the inner halo, mainly within ∼ 20 percent of the virial radius. We find haloes to be more spherical when hosting baryons. While the impact of baryons depends on the mass of the haloes, we also find a trend with morphology which suggests that the way baryons are assembled is also relevant in agreement with previous works. Our findings also indicate that disc galaxies preferentially form in haloes whose DMo counterparts were originally more spherical and with stronger velocity anisotropy. The presence of baryons alter the orbital structure of the DM particles of the haloes, which show a decrease in their velocity anisotropy, towards more tangentially biased orbits. This relative decrease is weaker in the case of disc-dominated galaxies. Our results point out to a cosmological connection between the final morphology of galaxies and the intrinsic properties of their DM haloes, which gets reinforce by the growth of the discs.Fil: Cataldi, Pedro Anselmo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Pedrosa, Susana Elizabeth. Universidad Autónoma de Madrid. Facultad de Ciencias; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Tissera, Patricia Beatriz. Pontificia Universidad Católica de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Artale, Maria Celeste. Universidad de Innsbruck; Austria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin
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