Using the Dark Energy Spectroscopic Instrument (DESI), the team, which includes UK scientists, has uncovered the largest ever collection of dwarf galaxies hosting active black holes.
The study also identified a record number of potential intermediate-mass black holes, remnants of the first black holes formed in the early Universe.
UK contributions
Mounted in a telescope in Arizona, DESI is an advanced instrument designed to study how dark energy influences the expansion of the Universe. It can capture light from 5,000 galaxies simultaneously.
Led by the US Department of Energy Lawrence Berkeley National Laboratory, the project involves over 900 researchers from more than 70 institutions worldwide.
The Science and Technology Facilities Council (STFC) supports the UK component of the study, which includes researchers from:
- Durham University
- the University of Portsmouth
- University College London (UCL)
Pushing the limits of the known Universe
Rahma Alfarsy, from the University of Portsmouth’s Institute of Cosmology and Gravitation, said:
The findings from this project illustrate DESI’s potential to push the limits of the known Universe.
Having witnessed the development and outcomes of this brilliant work, we are really excited to see what else will be unearthed from DESI’s treasure trove of extra-galactic observations.
Uncovering black holes
Astrophysicists are confident that massive galaxies, like the Milky Way, harbour black holes at their centre, but detecting black holes in smaller, low-mass galaxies is more difficult.
Dwarf galaxies, being much smaller and dimmer, make this an even greater challenge, due to their size and the limitations of current instruments.
However, when black holes are actively ‘feeding’, consuming material like gas, dust and stars, they release huge amounts of energy, which makes them easier to detect and study.
New insights
Using early data from DESI, the team analysed data from 410,000 galaxies, including approximately 115,000 dwarf galaxies, which contain thousands to billions of stars, but very little gas.
Led by the University of Utah, this data enabled the team to study the relationship between black holes and the evolution of dwarf galaxies.
Solving cosmic mysteries
The team also identified 300 potential intermediate-mass black holes, the largest collection ever discovered.
Most black holes are either small (less than 100 times the mass of our Sun) or supermassive (more than one million times the mass of our Sun).
Intermediate-mass black holes sit between these extremes. They are thought to be remnants of the first black holes formed just after the Big Bang, and beginnings of supermassive black holes at the centre of large galaxies today.
Although rare and difficult to detect, this discovery will help unlock the mysteries of these elusive objects.
Important UK contributions
Alongside Durham University, UCL and the University of Portsmouth as full member institutions, UK involvement in DESI also includes individual researchers at:
- University of Cambridge
- The University of Edinburgh
- University of St Andrews
- University of Sussex
- University of Warwick
Designing and building
Durham University helped to design and build the fibre optic cable system, which funnels light onto the spectrograph.
UCL helped to design and build the telescope’s mirror optical corrector.
UK researchers have also played a key role in the analysis, modelling and interpretation of the data.
Unlocking secrets
This latest research builds on major findings published last year, which produced the largest 3D map of the Universe ever created, revealing how it has expanded over the past 11 billion years.
These advancements underscore how DESI is transforming our understanding the hidden wonders of the Universe and its evolution.
Further information
Read the full paper published in the ‘Astrophysical Journal’.
The DESI collaboration is honoured to be permitted to conduct scientific research on Iolkam Du’ag (Kitt Peak), a mountain with particular significance to the Tohono O’odham Nation.
Top image: Credit: murat4art, iStock, Getty Images Plus via Getty Images.