This galaxy helps unveiling history of universe

A new study has provided a deeper into the history of the universe, it has been revealed.

A map of ionized helium in the galaxy, IZw18, has just been published which indicates the presence of peculiar stars similar to the first that ever shone in the universe.

The first galaxies were formed some 13.3 billion years ago, mainly composed of hydrogen and helium, the primary elements that emerged from the Big Bang. Their study to date has been technically very challenging due to their great distance from us, but the observation of analogous galaxies in our vicinity has turned out to be an excellent shortcut.

The study has found a very large region in this small galaxy of ionized helium, which tends to be more frequent in very distant galaxies with low presence of metals. The ionization of helium implies the presence of objects emitting a radiation intense enough to knock electrons off the helium atoms.

Using the PMAS integral field spectrograph of the 3.5 meter telescope at the Calar Alto Observatory (CAHA), researchers have obtained the first detailed map of this region of IZw18 and have analyzed possible ionizing sources.

Conventional sources of ionization, such as Wolf-Rayet stars, very massive and with very violent stellar winds, or shocks generated by remnants of supernovae, cannot provide the energy necessary to explain the halo of ionized helium present on IZw18, so researchers considered other possibilities.

This study showed how it was possible to extract information about the history of the universe within Earth's own galactic vicinity.