- First images of light from objects in the Universe are now recorded and split into thousands of colour components
- 4MOST will investigate the formation and evolution processes of stars and planets, the Milky Way and other galaxies and black holes
- Unprecedented collection of data resulting from investment by UK universities will put them at the global forefront of scientific exploration
A new four metre Multi-Object Spectroscopic Telescope (also known as 4MOST) has reached a milestone by capturing its 'first light' - meaning that it has recorded the first images of light from objects in the Universe and, importantly, split the light into 18,000 colour components.
The 4MOST science team consists of more than 700 investigators from universities and research institutes around the world. Among the nine UK universities involved are the University of Portsmouth and the University of Southampton .
The majority of telescopes in the world can only collect spectra (measurements of the dynamics and chemical composition of objects of interest) for one object at a time.
But, 4MOST has been equipped with over 2,400 fibres, each one the size of a human hair and with its own articulated arm so that when 4MOST points somewhere on the night sky, each fibre can move on to a galaxy or star of interest to measure its spectrum. This is where light from our objects of interest is spread out in order of wavelength, in a similar way to how light through a prism is ordered from red to blue.
This makes 4MOST capable of unravelling the light of 2,400 celestial objects at one time, allowing astronomers to study their detailed chemical composition and properties.
I am most excited by the overwhelming amount of data that will arrive from the number of telescopes across the world that the UK universities have invested in. Not only will this put us at the global forefront of scientific exploration, but it will also enable us to lead with the technical achievements necessary to analyse these observations
Dr Chris Frohmaier from the University of Portsmouth's Institute of Cosmology and Gravitation, Deputy Extragalactic Project Scientist for 4MOST and the Deputy Prinicipal Investigator of TiDES
By analysing the detailed rainbow-like colours of thousands of objects every 10-20 minutes, 4MOST will build a catalogue of temperatures, chemical compositions, velocities and many more physical parameters of tens of millions of objects spread across the entire Southern sky.
Much of the exploration and scientific analysis of the images is being undertaken by a collaboration within the 4MOST project, titled the 'Time-Domain Extragalactic Survey (TiDES)', of which the universities of Portsmouth and Southampton are founding members.
Dr Chris Frohmaier, from the University of Portsmouth's Institute of Cosmology and Gravitation , is the Deputy Extragalactic Project Scientist for 4MOST and the Deputy Prinicipal Investigator of TiDES. He developed the survey strategy and simulations for TiDES and has written the algorithms that will enable 4MOST to observe the largest ever spectroscopic sample of supernovae.
Commenting on the TiDES project, he said: "4MOST will enable us to collect spectra for the largest explosions in the Universe at unprecedented volumes and scale. These explosions, known as supernovae, will allow us to measure vast distances across the cosmos and study the mysterious force known as Dark Energy that is causing the accelerating expansion of the Universe.
"I am most excited by the overwhelming amount of data that will arrive from the number of telescopes across the world that the UK universities have invested in. Not only will this put us at the global forefront of scientific exploration, but it will also enable us to lead with the technical achievements necessary to analyse these observations."
Dr Phil Wiseman from the University of Southampton said: "4MOST is poised to crack the universe's biggest secrets. We'll be getting the most precise measurement ever of dark energy, the mysterious force tearing the cosmos apart.
"Through our TiDES work, we're building the largest catalogue of supermassive blackhole masses and unlocking the secrets of the universe's rapid evolution. By weighing a massive catalogue of 1,000 monster blackholes and observing 10,000 lensed galaxies, we will finally understand the engine driving cosmic expansion and galaxy growth."
TiDES will enable a better understanding of how stars evolve and die and contribute to the most precise measurements of the effects of a mysterious force, known as Dark Energy, on cosmic expansion and the fundamental make up of our Universe. It will also make high-precision measurements of the masses of almost 1,000 active supermassive black holes, and 10,000 strongly gravitationally lensed galaxies.
Ultimately this will transform the understanding of how galaxies and black holes grow together, unblocking the mystery of what drives the expansion and evolution of the Universe.
The project will collect the largest ever spectroscopic sample of supernovae, exploiting another of the UK's investments in astronomy in doing so - membership of the Legacy Survey of Space and Time (LSST) at the Vera C. Rubin Observatory.
Once fully operational, 4MOST will investigate the formation and evolution processes of stars and planets, the Milky Way and other galaxies, black holes and other exotic objects, and of the Universe as a whole.
4MOST is installed on the VISTA telescope (the Visible and Infrared Survey Telescope for Astronomy) at the European Southern Observatory's (ESO) Paranal Observatory in Chile. This gives a view of the sky of 2.5 degrees diameter - five times larger than the diameter of the moon.
More about the 'first light' observation
One of the objects dominating the First Light observation of 4MOST is the elongated galaxy NGC253, also called the Sculptor or Silver Coin galaxy. Except for the Magellanic Clouds, it is the galaxy with the largest apparent diameter in the southern sky with nearly the same diameter as the moon, only much fainter.
It was discovered by Caroline Herschel in 1783, is at a distance of about 11.5 million lightyears, and is known to currently form a lot of new stars.
The 4MOST observations also capture a super star cluster, various hot and cold stars and their movements, and gas glowing from newly formed stars in this galaxy.
The other large object seen in the field is the Globular Cluster NGC288, a very dense group of about 100,000 very old stars in the outskirts of the Milky Way. It formed about 13.5 billion years ago in the very earliest phases of the formation of the Milky Way. Its stars contain very small amounts of most chemical elements heavier than hydrogen and helium, reflecting its pristine composition.
Next to these two very large objects, 4MOST obtained spectra of more than 2,000 other objects in its first science observation. These include spectra of a large variety of bright and faint stars in our Milky Way and allow scientists to determine their temperature, mass, diameter, velocity, age and evolutionary stage, as well as their chemical composition.
Beyond the Milky Way, spectra of a pair of overlapping galaxies at 900 million lightyears were obtained, as well as spectra of more than a thousand other galaxies near and far - up to 10 billion light years - to determine their distance, internal velocity, star formation history or the mass of their central black hole.
