A team of astronomers including assistant professor Kate Whitaker at the University of Massachusetts Amherst reports today that they have by chance discovered faint traces of a huge galaxy never seen before, dating from the early universe. Likening the finding to photographing footprints of the mythical Yeti, the authors, led by postdoctoral fellow Christina Williams at the University of Arizona, say the scientific community once regarded such monster galaxies as folklore because there was no evidence for them, until now.
The authors say the discovery provides new insights into the first growing steps of some of the biggest galaxies in the universe. Details appear in the current Astrophysical Journal.
Whitaker, an expert in early galaxy formation and evolution, says, “These otherwise hidden galaxies are truly intriguing; it makes you wonder if this is just the tip of the iceberg, with a whole new type of galaxy population just waiting to be discovered.”
For this work, the astronomers used the ALMA – the Atacama Large Millimeter Array –a collection of 66 radio telescopes located in the high mountains of Chile. In new observations with extremely sensitive detection limits, Williams noticed a faint blob of light. “It was very mysterious,” she says, “but the light seemed not to be linked to any known galaxy at all. When I saw this galaxy was invisible at any other wavelength, I got really excited, because it meant that it was probably really far away and hidden by clouds of dust.”
Read more at University of Massachusetts at Amherst
Image: A team of astronomers at UMass Amherst, the University of Arizona and Swinburne University report that they have by chance discovered faint traces of a huge galaxy. The galaxy is undergoing an explosion of star formation, lighting up the gas surrounding the galaxy. Thick clouds of dust obscure most of the light, causing the galaxy to look dim and disorganized, very different from those seen today. (Credit: James Josephides, Swinburne Astronomy Productions, Christina Williams, University of Arizona and Ivo Labbé, Swinburne University)