Cosmological red shift free#

This ionized gas then recombines with free electrons to form atomic Hydrogen.

This means that the energetic photons they emit strip the molecular hydrogen in the surrounding gas of its electrons, thereby ionizing the gas. This line arises when massive bright stars we call O type stars ionize the hydrogen gas around them. There are a few spectral features that are especially important in MOSDEF galaxies. One such feature is Hα which can be found in the red part of the visible spectrum. In the lower part of the plot we have collapsed the spatial portion of the spectrum and are left with the 1D spectrum, where our spectral features appear as spikes. The top portion of the plot shows us the two dimensional spectrum, where the spectral features appear as black/white/black patterns. Figure 1: An example spectrum of a MOSDEF star forming galaxy. In the MOSDEF survey we use MOSFIRE, a multi-object near-infrared spectrometer on the Keck I Telescope in Hawaii to measure spectra of galaxies between 9.5 and 12.5 billion light years away.

Even galaxies that are 9 billion light years away have element footprints we can see using a spectrometer here on Earth. We call these patterns spectral features. Due to the cool nature of quantum mechanics (click here for more info), each element in the periodic table can only absorb or emit energy at specific wavelengths, which translates to distinct patterns in each element’s spectrum. A very useful tool in the study of far away galaxies is a spectrometer, an instrument that allows us to measure a spectrum, or the brightness of our light source at each wavelength.