# astro: black holes (as Q-ball-type saturons) could admit multi-vortex dynamics

<< Theoretical physicists argue that black holes admit vortex structures >>

Img << Sketch of a black hole endowed with multiple vortices. Colors denote the orientation, with the associated trapped magnetic field lines in black. Credit: Dvali et al. >>️

<< Recently, a new quantum framework for black holes, namely in terms of Bose-Einstein condensates of gravitons (the quanta of gravity itself), has been introduced, (..) Up until our article was published, rotating black holes have not been thoroughly studied within this framework. However, they might not only exist, but also be the rule rather than the exception. >> Florian Kühnel. 

️

Ingrid Fadelli. Theoretical physicists argue that black holes admit vortex structures. Phys.org. Sep 09, 2022. 

https://phys.org/news/2022-09-theoretical-physicists-black-holes-vortex.html

AA << argue that black holes admit vortex structure. This is based both on a graviton-condensate description of a black hole as well as on a correspondence between black holes and generic objects with maximal entropy compatible with unitarity, so-called saturons. (They) show that due to vorticity, a Q-ball-type saturon of a calculable renormalizable theory obeys the same extremality bound on the spin as the black hole. Correspondingly, a black hole with extremal spin emerges as a graviton condensate with vorticity. (..) Next, (AA) show that in the presence of mobile charges, the global vortex traps a magnetic flux of the gauge field. This can have macroscopically observable consequences. >>

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Gia Dvali, Florian Kuhnel, Michael Zantedeschi. Vortices in Black Holes. Phys. Rev. Lett. 129, 061302. Aug 3, 2022.  

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.061302

Also

keyword 'black hole' in FonT  

https://flashontrack.blogspot.com/search?q=black+hole

Keywords: astro, astrophysics, black hole, rotating black hole, vortex, vorticity

# gst: a rocking shadow dance: the broken disk.

AA << reveal a new phenomenon dubbed the "rocking shadow" effect that describes how disks in forming planetary systems are oriented, and how they move around their host star. The effect also gives clues as to how they might evolve with time. >>

<< Protoplanetary disks are often thought to be shaped like dinner plates—thin, round and flat. However, recent telescope images from the Atacama Large Millimeter/Submillimeter Array (ALMA) show that this is not always the case. Some of the disks seen by ALMA have shadows on them, where the part of the disk closest to the star blocks some of the stellar light and casts a shadow onto the outer part of the disk. From this shadow pattern, it can be inferred that the inner part of the disk is oriented completely differently to the outer part, in what is called a broken disk. >>️️

<< As the inner disk moved through the gravitational pull of the central star, the shadow it cast moved across the outer disk. But instead of the shadow pattern moving around the disk like a clock-hand as expected, it rocked back and forth with a see-saw-like motion. So although the inside disk kept turning in the same direction, its shadow looked like it was rocking forwards and backwards. >>

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Examining rocking shadows in protoplanetary disks. Royal Astronomical Society. Jul 15, 2022.

https://phys.org/news/2022-07-shadows-protoplanetary-disks.html

Rocking shadows in broken 

circumbinary discs. 

https://youtu.be/-0kAqc-sObY

The National Astronomy Meeting (NAM) 2022. The University of Warwick, 11th. Jul 15, 2022.

https://nam2022.org/

keywords: gst, astro, shadow, rocking shadow, broken disc

# astro: eight new echoing black hole binaries (in Milky Way)

<< Scattered across our Milky Way galaxy are tens of millions of black holes—immensely strong gravitational wells of spacetime, from which infalling matter, and even light, can never escape. Black holes are dark by definition, except on the rare occasions when they feed. As a black hole pulls in gas and dust from an orbiting star, it can give off spectacular bursts of X-ray light that bounce and echo off the inspiraling gas, briefly illuminating a black hole's extreme surroundings. >>

<< In a study appearing (..) in the The Astrophysical Journal, (AA) report (..) eight new echoing black hole binaries in our galaxy. Previously, only two such systems in the Milky Way were known to emit X-ray echoes. >>️

 << Kara (Erin Kara) and her colleagues are using X-ray echoes to map a black hole's vicinity, much the way that bats use sound echoes to navigate their surroundings. (..)  As a side project, Kara is working with MIT education and music scholars, Kyle Keane and Ian Condry, to convert the emission from a typical X-ray echo into audible sound waves. >>️️

Jennifer Chu. Search reveals eight new sources of black hole echoes. MIT.  May 2, 2022. 

https://phys.org/news/2022-05-reveals-sources-black-hole-echoes.html

https://youtu.be/iIeIag2Ji8k

Jingyi Wang, Erin Kara, et al. The NICER "Reverberation Machine": A Systematic Study of Time Lags in Black Hole X-Ray Binaries. ApJ. 930, 18. May 2, 2022. 

https://iopscience.iop.org/article/10.3847/1538-4357/ac6262

Also

keyword 'black hole' in FonT

https://flashontrack.blogspot.com/search?q=black+hole

keyword 'waves' in FonT

https://flashontrack.blogspot.com/search?q=waves

keyword 'onda' in Notes 

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=onda

Keywords: astro, black hole, echoes, waves

# astro: going beyond a performance by Frank Zappa (or a speech by – for example – a political entity), two speeds of sound found on Mars

AA << find that atmospheric sounds extend measurements of pressure variations down to 1,000 times smaller scales than ever observed before, revealing a dissipative regime extending over 5 orders of magnitude in energy. Using point sources of sound (Ingenuity rotorcraft, laser-induced sparks), (AA) highlight two distinct values for the speed of sound that are ~10 m/s apart below and above 240 Hz, a unique characteristic of low-pressure CO2-dominated atmosphere. (They) also provide the acoustic attenuation with distance above 2 kHz, allowing to elucidate the large contribution of the CO2 vibrational relaxation in the audible range. >>

Maurice, S., Chide, B., Murdoch, N. et al. In situ recording of Mars soundscape. Nature. doi: 10.1038/ s41586-022-04679-0. Apr 1, 2022. 

https://www.nature.com/articles/s41586-022-04679-0

<< All of these factors would make it difficult for two people to have a conversation only five meters (16 feet) apart >> Sylvestre Maurice.

Juliette Collen and Daniel Lawler. First audio recorded on Mars reveals two speeds of sound. Phys.org. Apr 1, 2022. 

https://phys.org/news/2022-04-audio-mars-reveals.html

NASA Perseverance Rover Captures 

Puff, Whir, Zap Sounds from Mars 

https://youtu.be/lX5iVyfF3N0

Also

Frank Zappa 

https://www.zappa.com/

image from  

https://www.zappa.com/sites/g/files/aaj776/f/styles/suzuki_breakpoints_image_tablet_16x9/public/news/202104/Zappa88-Home-banner-03.jpg

keywords: astro, mars, acoustics, sound, speed of sound, dissipative regimes, music, jazz, freejazz

# astro: aprops of horrific encounters, how to survive inside a (virtual) black hole

<< As (eight stars skirt a black hole 1m times the mass of the Sun) approach, all are stretched and deformed by the black hole's gravity. Some are completely pulled apart into a long stream of gas, a cataclysmic phenomenon called a tidal disruption event. Others are only partially disrupted, retaining some of their mass and returning to their normal shapes after their horrific encounters. >>

<< These simulations, (..) are the first to combine the physical effects of Einstein's general theory of relativity with realistic stellar density models. The virtual stars range from about one-tenth to 10 times the Sun's mass. >>

<< The division between stars that fully disrupt and those that endure isn't simply related to mass. Instead, survival depends more on the star's density. >>

Jeanette Kazmierczak. Scientists fling model stars at a virtual black hole to see who survives. NASA's Goddard Space Flight Center. Nov 26, 2021.

https://phys.org/news/2021-11-scientists-stars-virtual-black-hole.html

<< This paper introduces a series of papers presenting a quantitative theory for the tidal disruption of main-sequence stars by supermassive black holes (the pericenter-dependence of tidal disruption properties for eight stellar masses (..) and six black hole masses (..). >>

Taeho Ryu, Julian Krolik, et al. Tidal Disruptions of Main-sequence Stars. I. Observable Quantities and Their Dependence on Stellar and Black Hole Mass. ApJ 904 98. Nov 25, 2020.

https://iopscience.iop.org/article/10.3847/1538-4357/abb3cf

Also

keyword 'black hole' | 'astro' in FonT

https://flashontrack.blogspot.com/search?q=black+hole

https://flashontrack.blogspot.com/search?q=astro

keywords: astro, blackhole, tidal disruption, survival, surviving

# astro: the effect of Yarkovsky acceleration to direct the asteroid Apophis (towards us, hypothetically)

<< A University of Hawai Institute for Astronomy (IfA) astronomer has revealed critical new findings linked to a large asteroid expected to pass extremely close to Earth. Dave Tholen and collaborators have announced the detection of Yarkovsky acceleration on the near-Earth asteroid Apophis. This acceleration arises from an extremely weak force on an object due to non-uniform thermal radiation. This force is particularly important for the asteroid Apophis, as it affects the probability of an Earth impact in 2068. >>

Massive asteroid subject of new findings. Oct 26, 2020. 

https://www.hawaii.edu/news/2020/10/26/new-massive-asteroid-findings

"2068" –Massive Asteroid Apophis on Path for Earth Impact. Oct 27, 2020.

https://dailygalaxy.com/2020/10/2068-massive-asteroid-apophis-on-path-for-earth-impact

Also

il ciottolo Apophis. Notes. May 05, 2006 (quasi-stochastic poetry). 

https://inkpi.blogspot.com/2006/05/2001-il-ciottolo-apophis.html

A wicked list in the dino-killing range; waiting for new entries. FonT. Jun 29, 2017. 

https://flashontrack.blogspot.com/2017/06/s-astro-wicked-list-in-dino-killing.html

A few hints of our presence. Notes. Oct 13, 2006 (quasi-stochastic poetry)

https://inkpi.blogspot.com/2006/10/2073-few-hints-of-our-presence.html