... Keck spectroscopy and Spitzer Space Telescope analysis of the outer disk of the Triangulum SpiralGalaxy M33 . ... In an earlier study of the spiralgalaxy M33, we photometrically identified arcs or outer spiral arms of intermediate age (0.6 ...
... of NLSy1s galaxies - as it is usually done in comparative studies -, together with the well known observational biases, naturally favors the selection of sources with low black hole masses and high Eddington ratios that are hosted by blue spiralgalaxies ...
... to locate dense interstellar (IS) clouds in the Galaxy and probe a line-of-sight ... with each other and broadly correspond to the expected locations of spiral arms ...