Detecting Far Away Galaxies

Dropout Galaxy UVISTADR1 J100121.94+021937.6 — Three different images reveal galaxies in the area of Galaxy UVISTADR1 J100121.94+021937.6, which is visible only in the z filter image. Credit: Subaru HSC Survey, courtesy of the National Astronomical Observatory of Japan (NAOJ).

Unlike the nearby large spiral galaxy seen on the previous page, distant galaxies often look like smudges or blobs in images. Light from distant galaxies is shifted to longer wavelengths (redshifted) due to the expansion of the Universe. The light from the most distant galaxies is shifted so much that the galaxies are visible only in the longest infrared wavelength images.

Compare the images created from these filters and try to find the most distant galaxy.

Please answer all questions before continuing to the next page.