Fan et al published a paper several years ago that has since garnered over 200 citations, many of them recent. The authors studied the spectra of three objects at z~6 and determined that the objects are quasars, each with masses of several billions of Suns, residing in massive hosts, each with a lower mass limit of 10 trillion Suns. To top it off, the spectra of these objects indicate that they have super-solar metallicities. http://www.journals.uchicago.edu/AJ/journal/issues/v122n6/201316/201316.text.html [Broken] I have a question for the denizens of General Astronomy and Cosmology: Does the observation of extremely massive objects with super-solar metallicity at z~6 pose enough problems with the heirarchical model of structure formation to falsify the Big Bang theory? If not, at what epoch would such observations falsify the BB?