Advancing UK Aerospace, Defence, Security & Space Solutions Worldwide
  • Home
  • /
  • Space
  • /
  • Hidden galaxies may hold answers about Universe

Space

Hidden galaxies may hold answers about Universe

A team of scientists led by RAL Space, operated by the Science and Technology Facilities Council (STFC) and Imperial College London, has created the deepest ever image of the Universe in long far-infrared wavelengths, using newly processed data from the Herschel Space Observatory to reveal almost 2,000 distant galaxies, that could help answer key questions about our Universe.

Above: Image of countless stars against a blue background.
Courtesy STFC RAL Space    

The resulting image is called the Herschel-SPIRE Dark Field.

The research suggests the existence of a population of ‘hidden’ galaxies that could account for the missing energy in the Universe’s infrared light budget.

Advertisement
Leonardo RT

Dr Chris Pearson from STFC RAL Space, lead author of one of two papers published today in Monthly Notices of the Royal Astronomical Society, said: "This work has pushed the science with Herschel to its absolute limit, probing far below what we can normally discernibly see and potentially revealing a completely new population of galaxies that are contributing to the very faintest light we can observe in the universe."

Creating the deep image
Approximately half of our Universe remains hidden from direct observation, obscured by intervening cosmic dust.

To build a complete picture of the Universe and its evolution, astronomers must observe across multiple wavelengths of light, like long far-infrared wavelengths observed by Herschel’s SPIRE (Spectral and Photometric Imaging REceiver) instrument.

Above: SPIRE in a RAL Space cleanroom.
Courtesy STFC RAL Space

Dr Pearson explained: "The SPIRE instrument routinely stared at a single patch of ‘dark sky’ every month or so for the duration of its mission in space in order to monitor and measure its performance

"Our paper published today has taken each of these single observations – 141 images in total – stacking them on top of each other to create a final image known as the ‘Herschel-SPIRE Dark Field’.

"This new image will provide insight into the faintest galaxies in the cosmos that contribute to the infrared background light emitted by the universe, allowing scientists to drill down to the individual sources responsible for all the infrared light we see from space."

Importance of infrared observations
Dr Pearson highlighted the importance of observing the Universe in infrared light: "When we look at starlight through normal telescope, we are only able to read half of the story of our Universe, the other half is hidden, obscured by intervening dust.

"In fact, roughly half of the energy output of the Universe is from starlight that has been absorbed by dust and re-emitted as cooler infrared radiation. To fully understand the evolution of our Universe we need to observe the sky in both optical and longer wavelength infrared light."

Unexpected increase in galaxies
The analysis revealed possible evidence of a previously undiscovered population of faint galaxies hidden in the image blur, too faint to be detected by conventional methods. This unexpected increase in the number of galaxies is not predicted by current models.

Advertisement
Gulfstream RT

If proven to exist, this new population may provide the missing piece to account for all remaining infrared energy observed in the Universe.

Dr David Clements, astrophysicist at Imperial College, said: "These results show just how valuable the Herschel archive is. We’re still getting great new results more than 10 years after the satellite stopped operating.

"What we can’t get, though, is more data at these wavelengths to follow up these fascinating new results. For that we need the next generation far-IR mission, PRIMA, currently being proposed to NASA."

The next-generation far-IR mission
Dr Clements continues: "What we can’t get, though, is more data at these wavelengths to follow up these fascinating new results. For that we need the next generation far-IR mission, PRIMA, currently being proposed to NASA."

The Probe far-Infrared Mission for Astrophysics (PRIMA) is being supported by a UK consortium including:

  • RAL Space
  • the University of Sussex
  • Imperial College London
  • Cardiff University

It would involve the use of a 1.8m telescope optimised for far-infrared imaging and spectroscopy, bridging the gap between existing observatories such as the James Webb Space Telescope and radio telescopes.

PRIMA is one of two proposals shortlisted for NASA’s next $1 billion (£772 million) probe mission. NASA will confirm its final mission selection in 2026.

Advertisement
Babcock LB
UK launches tender for space debris removal

Space

UK launches tender for space debris removal

3 July 2025

The UK Space Agency has launched a major new procurement process to tackle the growing threat of space debris, initiating a £75.6 million tender for the nation’s first mission to actively remove defunct satellites from orbit.

Boeing appoints Stephen Parker as CEO of BDS

Defence Security Space

Boeing appoints Stephen Parker as CEO of BDS

3 July 2025

Boeing today announced Stephen (Steve) Parker as president and chief executive officer of its Defense, Space & Security (BDS) business, effective immediately. Parker has served as interim leader of the Boeing business unit since September 2024.

UK students to launch international space mission

Space

UK students to launch international space mission

3 July 2025

A team of students from the University of Surrey, the University of Portsmouth and the University of Southampton are working to fit equipment they designed, made and tested to a suborbital launch vehicle which aims to launch 900km into space.

Airbus-built Sentinel-4 launched onboard MTG weather satellite

Space

Airbus-built Sentinel-4 launched onboard MTG weather satellite

2 July 2025

The European Space Agency (ESA) and its partners have confirmed the successful launch of the Airbus-built Sentinel-4, a cutting-edge air quality monitoring instrument hosted on the third generation Meteosat (MTG-S1) weather satellite.

Advertisement
Teledyne
Teledyne CIS120 sensors launch on GOSAT-GW

Space

Teledyne CIS120 sensors launch on GOSAT-GW

1 July 2025

Teledyne Technologies Incorporated, a provider of advanced imaging solutions, has confirmed that two CIS120 sensors designed and manufactured by Teledyne Space Imaging will play a major part in the third in a series of Japanese climate change and Earth observation satellite missions.

Expleo’s science-based climate action targets approved by SBTi

Aerospace Defence Space

Expleo’s science-based climate action targets approved by SBTi

27 June 2025

Expleo's near and long-term science-based emissions reduction targets have been validated by the Science Based Targets initiative (SBTi).

Advertisement
DSEI 2025