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The Galaxy Zoo citizen science website invites anyone with an Internet connection to participate in research by classifying galaxies from the Sloan Digital Sky Survey. As of April 2009, more than 200,000 volunteers had made more than 100 million galaxy classifications. In this paper, we present results of a pilot study into the motivations and demographics(More)
Galaxy formation is significantly modulated by energy output from supermassive black holes at the centers of galaxies which grow in highly efficient luminous quasar phases. The timescale on which black holes transition into and out of such phases is, however, unknown. We present the first measurement of the shutdown timescale for an individual quasar using(More)
Isotopic abundance ratios 24 Mg: 25 Mg: 26 Mg are derived for 20 stars from high-resolution spectra of the MgH AX 0-0 band at 5140Å. With the exception of the weak G-band giant HR 1299, the stars are dwarfs that sample the metallicity range-1.8 < [Fe/H] <0.0. The abundance of 25 Mg and 26 Mg relative to the dominant isotope 24 Mg decreases with decreasing(More)
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