Hubble finds oldest known spiral galaxy
JUL 19, 2012
DOI: 10.1063/PT.5.026180
Los Angeles Times : Most galaxies from the earliest period of galactic formation, about 3 billion years after the Big Bang, have irregular shapes. BX442, one of more than 300 galaxies examined by a team of astronomers using the Hubble Space Telescope, is an exception. Initially thinking the spiral appearance was caused by the alignment of two galaxies, the astronomers turned to spectra images from the W. M. Keck Observatory in Hawaii. The images showed that the 10.7-billion-year-old BX442 was, in fact, a rotating grand-design spiral galaxy. Current theories don’t predict that this form of spiral galaxy, with well-defined arms, should form so early in the universe. One possible explanation is the gravitational influence of a nearby dwarf galaxy, which simulations show could produce the spiral appearance.
© 2012 American Institute of Physics
