An undoubtedly essential stage in a galaxy’s life is when it begins to birth hot brand-new stars and brighten the night sky. However for years, scientists have actually struggled to find out precisely how these stars are born from the gas that remains in between galaxies, called the intergalactic medium. It’s been thought that there’s an early phase in galaxy development where hot gas builds up considerably, however stars have not yet begun forming. This has actually been described as a “dark stage,” and much like its name, its absence of starlight makes it near difficult to observe. However just recently, a group of scientists has actually recognized 6 “dark galaxy” prospects, which might close an important evolutionary space in galaxy development.
Led by Raffaella Anna Marino and Sebastiano Cantalupo of ETH Zurich’s Department of Physics, a group of scientists looked for these dark galaxies utilizing among deep space’s natural flashlights– quasars. Their work was released in The Astrophysical Journal on Might 23.
Referred to as the brightest things in deep space, quasars give off amazing quantities of ultraviolet light. This extreme energy triggers neighboring hydrogen atoms to give off fluorescent light, called the Lyman-alpha line. Because hydrogen is a crucial element in galaxy development, it’s thought to be present in all phases of stellar development, consisting of the dark stage. So if a dark galaxy remains in close distance to a brilliant quasar, event UV light will trigger the otherwise concealed item’s hydrogen to produce noticeable, fluorescent light.
Utilizing quasars to look for dark galaxies isn’t really a brand-new method, however discovering them at such far ranges was difficult in the past. Nevertheless, with the assistance of the Multi System Spectroscopic Explorer (MUSE) instrument, connected to the European Space Observatory (ESO)’s Large Telescope (VLT), the research study group had the ability to survey an area of remote quasars– one that had actually formerly been too far to see.