Stars undergoing explosions in “zombie” galaxies generate cosmic dust that has the potential to give rise to planets and even life, as per recent findings by scientists.
Elliptical galaxies, often referred to as “red and dead” or “zombie” galaxies, are composed of aging stars that lack the necessary energy for the explosive supernovae events crucial for planet formation. Despite this, studies conducted by Cardiff University have uncovered a significant presence of dust in these seemingly lifeless galaxies.
To investigate the origin of this unexpected cosmic dust, astronomers analyzed the aftermath of a low-energy supernova in an elliptical galaxy located more than 300 million light years away. The researchers discovered that when the original star, part of a binary system, exploded, the resulting shock wave interacted with material ejected by both itself and its companion star, leading to the formation of dust particles.
These findings shed light on a novel source of cosmic dust particles, believed to serve as the building blocks for celestial bodies like planetesimals, rocky planets, and potentially life forms throughout the universe.
Professor Haley Gomez, the Head of Cardiff University’s School of Physics and Astronomy, highlighted the significance of this discovery, noting the substantial amount of cosmic dust equivalent to 1 percent of the Sun’s mass produced just 1,041 days post-explosion in the elliptical galaxy.
The research team employed various space-based telescopes, including Nasa’s Spitzer and Neowise missions, along with ground-based observatories in China, South America, and Australia, to monitor the evolution of the zombie supernova explosion over a three-year period. Data analysis revealed a decrease in visible light from the supernova over time, indicating the dust’s ability to obscure the luminosity while emitting a brighter infrared glow.
The study emphasizes the necessity of interaction between the supernova’s ejecta and a companion star, typically a younger and slightly more massive star, to facilitate substantial dust production. This contrasts previous assumptions that dust formation primarily occurred in Type II supernovae, which result from the core collapse of massive stars.
Professor Andy Howell from Las Cumbres Observatory and the University of California Santa Barbara underscored the significance of dust formation as a process of gas cooling and condensation, ultimately leading to the formation of planetesimals and planets. This continuous cycle of creation following stellar demise underscores the intricate balance of life and death in the cosmic realm.
The research findings, published in Nature Astronomy, mark a significant advancement in understanding the mechanisms behind cosmic dust formation and its role in shaping planetary systems within galaxies.