University of Tsukuba | Center for Computational Sciences

Solving the Mysteries of the Universe with Computational Astrophysics
Supermassiveblackholesandjets
Supermassive black holes and jets
Every galaxy is thought to contain a supermassive black hole (SMBH) at its center. Their existence is deduced indirectly
through their gravitational interactions with surrounding stars and gas. SMBH have also been predicted to cast shadows
outlined by a ring of confined light. Sometimes, SMBH launch magnetized powerful jets.
Recently, the Event
Horizon Telescope(EHT) captured the firstimage of a black holeshadow confirming theexistence of asupermassive blackhole at the center ofM87.

Synthetic image withpolarization vectorsof the M87 SMBH shadow

Volume render of jet- galactic disc system

We succeeded in producing a synthetic image (above) of theblack hole shadow through a combination of generalrelativistic magnetohydrodynamic simulations and radiativetransfer of polarized light, predicting regions of linearlypolarized light. New EHT observations of polarized light canreveal the topology of the magnetic fields around the SMBH.

The powerful jets from SMBH at the centers ofgalaxies interact strongly with the interstellar
medium of the galaxy. We captured thesecomplicated effects with relativistic hydrodynamic
simulations showing how the turbulence andoutflows generated through the interactions affectthe star formation history of a galaxy.

Tsunetoe, Mineshige, Ohsuga, Kawashima, Akiyama, submitted PASJ

Mukherjee, Wagner, Bicknell, Silk, Sutherland, MNRAS 2018

4Arata et al.

Galaxy formation in the early, distant universe – simulations meet observations
Observing galaxies in the distant, early universe is challenging as they become rarer and fainter, but recent observationsat infrared and ultraviolet wavelengths of massive, gas- and dust-rich galaxies with extreme star-formation rates arechallenging our theoretical understanding of the formation of some of the earliest galaxies.
We implemented a new recipe for the energy and momentum injection due
to supernovae in our cosmological smooth-particle hydrodynamics code,with which we modelled with unprecedented detail galactic winds driven bysupernovae. The simulations successfully reproduced complex observations,e.g., the distribution of metals (all elements other than hydrodgen andhelium) in isolated galaxies.
Shimizu, Todoroki, Yajima, Nagamine, 2019, MNRAS, 484, 2632

Infrared surface brightness of asimulated high-redshift galaxy

We performed multi-waveband radiative transfer calculations through highresolution cosmological hydrodynamical simulations that follow the formationand evolution of the first galaxies. We produced synthetic observational
images of what the galaxies would look like in the infrared and UV. The
infrared and UV brightness can vary tremendously in response to the energetic
feedback by supernovae.
Arata, Yajima, Nagamine, Khochfar, Li, 2019, MNRAS, 488, 2629

F i g u r e 1 . M ap s of the m ain galaxy in H alo-11 run at z ⇠ 6. Top panels: Colum n density of gas ( left) , stars ( m iddle) and dust ( right) .
panels:D ust tem p erature ( left) , surface brightness of the rest-fram e U V continuum ( m iddle) andthe observed-fram e sub-m m
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continuum ( right) . T he pix el size is ⇠ 0.02 arcsec. T he spatial scale of 5 kp c ( physical) is displayed in the b ottom left panel.