Using a new computational approach, Sissa’s researchers were able to perform incredible calculations. In addition, according to their research, about 1% of ordinary matter (baryonic) is trapped in stellar-mass black holes.
How many black holes are there in the universe? This is one of the most relevant and pressing questions in modern astrophysics and cosmology. This interesting issue was recently raised by Sissa PhD. Student Alex Sicilia, under the guidance of Professor Andrea Labbe and Dr Lumen Boco, with other collaborators from SISSA and from other national and international institutions. In the first paper in a series recently published in astrophysics journal, The authors investigated the demographics of stellar-mass black holes, which are black holes with masses ranging from a few to hundreds of solar masses, that appear at the end of the life of massive stars.
The innovative character of this work is to combine detailed models of stellar and binary evolution with advanced recipes for star formation and mineral enrichment in individual galaxies. This is one of the first, and one of the most powerful, early ab accounts for stars
black hole-A black hole is a place in space where the pull of gravity is so strong not even light can escape it. Astronomers classify black holes into three categories by size: miniature, stellar, and supermassive black holes. Miniature black holes could have a mass smaller than our Sun and supermassive black holes could have a mass equivalent to billions of our Sun.-“>Black hole The function of mass through cosmic history. -” Alex Cecilia, first author of the studyAccording to new research, a large amount of about 1% of the normal (baryonic) matter in the universe is trapped in stellar-mass black holes. Amazingly, the researchers found that the number of black holes in the observable universe (a sphere about 90 billion light-years in diameter) is currently about 40 billion billion (that is, about 40 x 10).18, which is 4 followed by 19 zeros!)
A new method for counting the number of black holes
As the study authors explain: “This important result was obtained thanks to an original approach combining the latest stellar evolution code and the SEVN binary developed by SISSA researcher Dr. Mario Spira for the recipe for experimental physics related to the properties of galaxies, especially the rate of star formation, the amount of stellar mass, and the metallic interstellar medium (all of which are important components for determining the number and mass of stellar black holes.) By utilizing these important components independently approach consistent, thanks to their new computational approach, the researchers then deduced the number and mass distribution of stellar black holes throughout the history of the universe. Comments Alex Cecilia, first author For this study, he said, “The innovative character of this work lies in combining detailed models stellar and binary evolution with advanced recipes for star formation and mineral enrichment in individual galaxies. This is one of the first and most powerful beginner calculations of the mass function of a stellar black hole in cosmic history. “
What is the origin of the most massive stellar black holes?
Estimating the number of black holes in the observable universe is not the only problem scientists are investigating in this study. Working closely with Dr. Ugo Di Carlo and Professor Michela Mapelli of the University of Padua, they also explored the different formation channels of black holes with different masses, such as isolated stars, binary systems, and star clusters. According to their research, the most massive stellar black holes arise mainly from dynamic events in star clusters. In particular, the researchers show that such an event is needed to explain the mass function of black hole mergers as predicted from observations of gravitational waves by
LIGO-The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory supported by the National Science Foundation and operated by Caltech and MIT. It’s designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. It’s multi-kilometer-scale gravitational wave detectors use laser interferometry to measure the minute ripples in space-time caused by passing gravitational waves. It consists of two widely separated interferometers within the United States—one in Hanford, Washington and the other in Livingston, Louisiana.-“>Lego/ Virgo collaboration.Lumen Boco, co-author of the paper, comments: “Our work provides a robust theory for the generation of light seeds for supermassive (super) black holes at high redshift, and may serve as a starting point for investigating the origin of the ‘heavy’ origin. seeds,’ which we will follow up on in a future paper.
Interdisciplinary work carried out in the context of “BiD4Best – Application of Big Data for the Study of Black Hole Evolution”
Professor Andrea Lappé, Cecilia Supervisor and Thesis Coordinator of Ph.D. In Astrophysics and Cosmology at SISSA, he adds: “This research is truly interdisciplinary, covers aspects, and requires expertise in stellar astrophysics, galaxy formation and evolution, gravitational waves and multi-message astrophysics; therefore, it requires the collaborative efforts of the different members within the SISSA Astrophysics and Cosmology Group, and a strong network with external collaborators.”
Alex Sicilia’s work takes place in the context of the prestigious Innovative Training Network project “BiD4BEST – Application of Big Data for the Study of Black Hole Evolution” co-authored by Professor Andrea Lappi of SISSA (Project H2020-MSCAITN-2019 860744), funded by the European Union with a total about 3.5 million euros; It includes many academic and industrial partners, to offer Ph.D. Trained 13 early-stage researchers in the formation and evolution of black holes, utilizing advanced data science techniques.
Reference: “Black hole mass function through cosmic time. I. Star black holes and light seed distribution” by Alex Cecilia, Andrea Lappé, Lumen Pocco, Mario Spra, Ugo in de Carlo, Michela Mapelli, Francesco Shancar, David M. Alexander, Alessandro Bressan and Luigi Danes, 12 January 2022, Astrophysics Journal.
DOI: 10.3847 / 1538-4357 / ac34fb–
