Karan Akbari
Astrophysics researcher: X-ray timing and spectroscopy of black hole binaries, simulation-based inference and machine learning for astronomy, periodicity searches in large surveys, and simulations.
Play
Interactive 3D toys built from my papers and code. They run in the browser.
Inside an X-ray binaryZoom from the whole binary to the black hole, and find the signals we'd actually see from Earth.
Take its pulseFind out if the disc really heats up and cools down every beat.
Spot the binaryFind the quasars that hide a real pair of black holes, without falling for the fakes.
The fit that can't tellPut a small error in a simulated X-ray detector's energy scale and watch the spectral fit absorb it.
The chirpFollow a pair of black holes to the merger and see which detector could hear it.
Research
Below is what I've worked on so far.
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Published · ApJ
A black hole with a heartbeat
GRS 1915+105 is a black hole that flares every 50 to 100 seconds.
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Published · ApJ
Looking for two black holes orbiting each other
If two supermassive black holes are orbiting each other, the light should go up and down with the orbit.
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Neural networks can fit an X-ray spectrum in milliseconds, which is great, as long as the data looks like what they trained on.
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Preprint
One star or two?
A white dwarf next to a normal star adds some extra blue light to the spectrum, so you can find these pairs in Gaia data.
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Side project · stopped, might come back
Could something alive be made of plasma?
If something really lived on the surface of the Sun, it would probably have to be made of the stellar plasma too.
The papers are on the Research page. The code for most of this, plus other projects, is on the Code page.
Now
- WritingA paper on supermassive black hole binaries in the TNG simulations.
- WritingA new paper on the GRS 1915+105 heartbeat.
- AnalysisWith Sudip Bhattacharyya, on which X-ray time lags you can actually measure when one detector is good at energies and another is good at timing.
Quotes I like
“Whatever you do, don't reveal all your techniques in a YouTube video, you fool, you moron.”
“Disobedience, in the eyes of anyone who has read history, is man’s original virtue.”
Notes
- The 2% that was actually 55%A dead end from the Gaia paper
- Things I learned doing researchCheck your inputs, zero is a result, good fits can be wrong
- Space things I likeThe Eagle Nebula and GRS 1915+105
All four are on the Notes page.