E.P.A. Cancels Talk on Climate Change by Agency Scientists by LISA FRIEDMAN


By LISA FRIEDMAN

Organizers of a Monday conference on the Narragansett Bay were told three E.P.A. scientists would not be allowed to present their work.

Published: October 22, 2017 at 01:39PM

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Two Black Holes Dancing in 3C 75

What’s happening at the center of active galaxy 3C 75? The two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away. Astronomers conclude that these two supermassive black holes are bound together by gravity in a binary system in part because the jets’ consistent swept back appearance is most likely due to their common motion as they speed through the hot cluster gas at 1200 kilometers per second. Such spectacular cosmic mergers are thought to be common in crowded galaxy cluster environments in the distant universe. In their final stages the mergers are expected to be intense sources of gravitational waves. via NASA http://ift.tt/2gWCW4t

Lynds Dark Nebula 183

Beverly Lynds Dark Nebula 183 lies a mere 325 light-years away, drifting high above the plane of our Milky Way Galaxy. Obscuring the starlight behind it when viewed at optical wavelengths, the dark, dusty molecular cloud itself seems starless. But far infrared explorations reveal dense clumps within, likely stars in the early stages of formation as enhanced regions of the cloud undergo gravitational collapse. One of the closest molecular clouds, it is seen toward the constellation Serpens Caput. This sharp cosmic cloud portrait spans about half a degree on the sky. That’s about 3 light-years at the estimated distance of Lynds Dark Nebula 183. via NASA http://ift.tt/2x9BMbW

A Beautiful Trifid

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. But the red emission region roughly separated into three parts by obscuring dust lanes is what lends the Trifid its popular name. Pillars and jets sculpted by newborn stars, below and left of the emission nebula’s center, appear in famous Hubble Space Telescope close-up images of the region. The Trifid Nebula is about 40 light-years across. Just too faint to be seen by the unaided eye, it almost covers the area of the Moon in planet Earth’s sky. via NASA http://ift.tt/2xPeO9M