HEL Why is it important to have range of tools that can measure all parts of the electromagnetic spectrum

This tiny slice of the universe, speckled with galaxies near and far, tells the story of galaxy evolution over cosmic time Among the 10,000 or so galaxies
pictured here are newborns, adolescents, adults and retirees Like looking through a vast collection of family photos, astronomers are poring over this
comprehensive image to see how galaxies grew up, matured, and aged
This portrait of our universe's history is called the Hubble Ultra Deep Field (or HUDF). It is a minuscule patch of sky first targeted by the Hubble Space
Telescope in 2002 and revisited over and over again since then. This version of the HUDF is extra special though It combines observations of the field
taken with Hubble's Advanced Camera for Surveys and the Wide Field Camera 3 from 2002 to 2012, providing one of the farthest views into the universe
we've ever seen Plus, it includes light not just from the visible part of the spectrum but from the invisible) infrared and ultraviolet ranges, too, giving us
different details of the story of how galaxies came to be
Infrared light lets us see the universe's youngest galaxies. These galaxies lie far far away from us, and as their light travels across the universe, it gets
stretched by the expansion of space Wavelengths of visible light grow longer becoming infrared light by the time it reaches us Combining Hubble's
observations of the HUDF in visible and infrared light a team of astronomers led by Garth Illingworth of the University of California identified more than
5,500 galaxies in a central portion of the field some so faint that they are just one ten-billionth the brightness of what the human eye can see Another
team headed by Richard Ellis of the California Institute of Technology (Caltech) used Hubble's infrared observations to find galaxies more than 13 billion
light-years away, when the universe was only about 400 million years old - or about three percent of its present age
Alternatively, to understand slightly older growing galaxies that are not so far away, observing in ultraviolet light is best The hottest and youngest stars
give off huge amounts of ultraviolet light making them easy to spot at those wavelengths of light Most recently, a team of astronomers led by Harry
Teplitz of Caltech used the ultraviolet-sensing abilities of Hubble's Wide Field Camera 3 to add the ultraviolet piece to this view of the HUDF With this
part of the galaxy evolution picture in hand, astronomers are investigating how galaxies grew through bursts of star formation and exactly where when
and how many stars formed over time
Because our atmosphere blocks or absorbs most infrared and ultraviolet light that reaches Earth only a telescope in space, like Hubble, can provide
such insights into the history of galaxies Without both infrared and ultraviolet light, the tale is incomplete.