HAWK-I peers through the dust

The European Space Observatory’s Very Large Telescope (VLT) has capture the central part of the Milky Way with spectacular resolution and found evidence of a burst of star formation so intense that it resulted in over a hundred thousand supernova explosions.

In a paper published in the journal Nature Astronomy, a research team led by the Institute of Astrophysics of Andalusia in Spain reports that about 80% of the stars in the galaxy’s central region formed in its early years, between eight and 13.5 billion years ago. 

This was followed by about six billion years during which very few stars were born. This was brought to an end by an intense burst of star formation around one billion years ago.

“The conditions in the studied region during this burst of activity must have resembled those in ‘starburst’ galaxies, which form stars at rates of more than 100 solar masses per year,” says Francisco Nogueras-Lara, who is now based at the Max Planck Institute for Astronomy in Germany. 

“This burst of activity, which must have resulted in the explosion of more than a hundred thousand supernovae, was probably one of the most energetic events in the whole history of the Milky Way.” 

To capture this high-resolution image, the researchers used broadband filters J (centred at 1250 nanometres, in blue), H (1635 nanometres, in green), and Ks (2150 nanometres, in red), to cover the near infrared region of the electromagnetic spectrum. 

By observing in this range of wavelengths, the HAWK-I instrument on the VLT can peer through the dust, allowing it to see certain stars in the central region of our galaxy that would otherwise be hidden.