English: This image shows the winding green filaments observed by the NASA/ESA Hubble Space Telescope within eight different galaxies. The ethereal wisps in these images were illuminated, perhaps briefly, by a blast of radiation from a quasar — a very luminous and compact region that surrounds a supermassive black hole at the centre of a galaxy. In each of these eight images a quasar beam has caused once-invisible filaments in deep space to glow through a process called photoionisation. Oxygen, helium, nitrogen, sulphur and neon in the filaments absorb light from the quasar and slowly re-emit it over many thousands of years. Their unmistakable emerald hue is caused by ionised oxygen, which glows green. The Hubble team found a total of twenty galaxies that had gas ionised by quasars; those featured here are (from left to right on top row) the Teacup (more formally known as 2MASX J14302986+1339117), NGC 5972, 2MASX J15100402+0740370 and UGC 7342, and (from left to right on bottom row) NGC 5252, Mrk 1498, UGC 11185 and 2MASX J22014163+1151237.
This file is in the public domain because it was created by NASA and ESA. NASA Hubble material (and ESA Hubble material prior to 2009) is copyright-free and may be freely used as in the public domain without fee, on the condition that only NASA, STScI, and/or ESA is credited as the source of the material. This license does not apply if ESA material created after 2008 or source material from other organizations is in use.
NASA, ESA, Galaxy Zoo Team and W. Keel (University of Alabama, USA)
来源
ESA/Hubble
简短标题
Hubble spies eight green filaments lit up by past quasar blasts
图像标题
This image shows the winding green filaments observed by the NASA/ESA Hubble Space Telescope within eight different galaxies. The ethereal wisps in these images were illuminated, perhaps briefly, by a blast of radiation from a quasar — a very luminous and compact region that surrounds a supermassive black hole at the centre of a galaxy. In each of these eight images a quasar beam has caused once-invisible filaments in deep space to glow through a process called photoionisation. Oxygen, helium, nitrogen, sulphur and neon in the filaments absorb light from the quasar and slowly re-emit it over many thousands of years. Their unmistakable emerald hue is caused by ionised oxygen, which glows green. The Hubble team found a total of twenty galaxies that had gas ionised by quasars; those featured here are (from left to right on top row) the Teacup (more formally known as 2MASX J14302986+1339117), NGC 5972, 2MASX J15100402+0740370 and UGC 7342, and (from left to right on bottom row) NGC 5252, Mrk 1498, UGC 11185 and 2MASX J22014163+1151237.