An international team of astronomers led by SRAP member Dr Cristina Martínez-Lombilla (School of Physics at UNSW Science) has used a new technique to study the faint light between galaxies, known as “intra-group light,” shedding light on the stars within it.
Dr Cristina Martínez-Lombilla (School of Physics at UNSW Science).
The researchers successfully detected and characterized the intra-group light, which is approximately 50 times fainter than the darkest night sky on Earth. By analyzing the properties of the stray stars between galaxies, the team found that the intra-group light is younger and less metal-rich compared to the surrounding galaxies.
They also discovered that the orphan stars in the intra-group light appear to have a different origin, resembling the nebulous “tail” of a more distant galaxy. This indicates that these stars were likely stripped from their home galaxies due to tidal stripping caused by the gravitational pull of massive satellite galaxies.
Light ‘between’ the galaxies – the ‘intra-group light’ – however dim, is radiated from stars stripped from their home galaxy. Image credit: Cristina Martínez-Lombilla (School of Physics at UNSW Science)
The study provides valuable insights into the interaction history and evolution of groups of galaxies and paves the way for future analyses of intra-group light using advanced telescopes.
UNSW has published today a media release about this research, with the title “Astronomers observe intra-group light – the elusive glow between distant galaxies”. The research article has been published in the prestigious research journal “Monthly Notices of the Royal Astronomical Society” (MNRAS).