Pareidolia / X-ray Emission in Dual AGNs
a collaboration between Ariane Ben Eli, Alexander Hiller, and John Staunton
Pareidoliamedium: magnetized iron, sand, paint, light
Several pages into John's paper entitled Evolution of Extended X-ray Emission in Dual Active Galactic Nuclei (DAGN), I found images or representations of the DAGN that were described in the paper. I was immediately struck by the recognizable figures I saw in the images—a butterfly, a bird of prey, a tree frog, the figure of a woman emerging from mist. Of course, I thought of the man in the moon, or the rabbit in the moon—pareidolia—the tendency to see recognizable figures or patterns in objects. The entomologist who announced he had identified insects on Mars was experiencing pareidolia. If you watch the video I created in response to the paper, you might experience pareidolia, too. Ariane Ben Eli is a very serious artist. She has a very serious interest in astronomy that dates back to a childhood in Tucson, Arizona, a city surrounded by telescopes. The lenses inside the original Mars rover, and also inside the Hubble space telescope also originated in Tucson. Switching from painting to video for this project was a welcome challenge, as Ariane has become somewhat of an armchair epidemiologist and infectious disease expert in the last few weeks, and she would happily substitute thinking about dual active galactic nuclei for Covid-19 any day.
Alexander Hiller is a GS student studying screenwriting and narrative. He loves space and hopes to combine all his loves into one giant film. See him on twitter @hillerthriller |
Evolution of Extended X-ray Emission in Dual Active Galactic Nuclei(this research paper is not yet published, but the abstract below can be found online!)
We investigate the physical properties of the extended X-ray emission in a sample of nearby dual Active Galactic Nuclei (dual AGNs): Mrk 266, Mrk 463, NGC 6240 and Arp 220. We find that the dual AGNs in an intermediate merger stage, Mrk 266 and Mrk 463, have shock heated gas, which is the result of accelerating cold gas, with temperatures greater than 0.9 keV or star forming regions with temperatures below 0.9 keV. Late stage mergers show similar soft X-ray spectra, but have an additional hard X-ray power law as a result of reflection and scattering of AGN outflows on hot ions. We conclude that the extended emission of dual AGNs varies with merger stage, with intermediate stages characterized by heated gas emitting in the soft X-ray regime, while late stage systems are characterized by AGN outflows contributing to the hard X-ray regime. These results are also consistent with the simple analytic model put forward here, using results from magnetohydrodynamics and radiative processes. Further analysis of larger dual AGN samples could confirm this as the general process by which X-rays are emitted in these events. John Staunton is a senior undergraduate at Columbia College majoring in physics. He wants to study gravity and its effects in black holes and the early universe in graduate school.
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