Sihao Cheng

I am a postdoc studying astrophysics at the Institute for Advanced Study at Princeton. I love classical music, kendo, and anime.

[Siyu Yao @Yao__Siyu]

Our new paper just came out!
More scientists are seeing the promise of finding real-world features with ML+XAI. We examine what scientists mean when they talk about features here, and how this can be useful/misleading.
https://t.co/mPv5OCRBCK

[Sihao Cheng @SihaoCheng]

@dr_guangtou @RAS_Journals In overleaf, you may just type the Chinese characters in the line of authors, but then include the line of "\maketitle" inside the Chinese environment, like below:
\begin{CJK}{UTF8}{gkai}
\maketitle
\end{CJK}
instead of doing it for the line of explicit author names.

[Song Huang @dr_guangtou]

Have to say, the price of insulin in the U.S always triggers me...It feels like murder given how cheap it can be and how critical it is to a large population...

[Song Huang @dr_guangtou]

So @BBCNews did a short documentary about Covid-19 and Wuhan...In the opening scene, they put Wuhan like 1000 miles away from where it really is...

That yellow spot is Wuhai, Inner Mongolia (乌海); not Wuhan (武汉)

You may say negligence, I say arrogance

[Sihao Cheng @SihaoCheng]

A boring footnote: our logic chain is: high velocity -> 22Ne -> C/O core -> merger, not directly high velocity -> merger, because the merger delay (less than the extra cooling delay) is not important on the Q branch (but important above the branch) 8/8

[Sihao Cheng @SihaoCheng]

Do we really understand the cooling of white dwarfs? Yes, and no. Thanks to Gaia DR2, an amazing feature called the "Q branch" on the HR diagram is revealed. We show that this huge branch is connected to an anomaly of white dwarf cooling: https://t.co/9wkPF87gAj (updated) 1/8

[Sihao Cheng @SihaoCheng]

So, we have shown a cooling anomaly and proposed a possible explanation. Should we say that we understand or not understand the white dwarf cooling now? 7/8

[Sihao Cheng @SihaoCheng]

@jotajotahermes @arxiv @crohnslifter @astrowizicist @kenjshen I agree with you. Moreover, according to Kilic et al. (2018) LP 93-21 has [C/He] ~ -3.5, similar to other DQ white dwarfs on the Q branch. So, maybe it is really a very old white dwarf having just finished its long stay on the Q branch.

[Sihao Cheng @SihaoCheng]

@astrocrash @jotajotahermes The energy release also depends on the density change between the two materials. The O sedi. replaces some C by O in the core, and 22Ne settling some C/O by 22Ne. I think for a given pressure, the density change of C->O replacement is tiny, but for C/O->22Ne, it is much larger.

[Sihao Cheng @SihaoCheng]

@fisherastro @jotajotahermes It might be a bit boring but at least the DQs on the Q branch are not magnetic, different from the hot-DQs. I show the magnetic and non-magnetic DQs in figure 8 of the paper JJ mentioned (https://t.co/9wkPF8oRrR). By the way I have a new webpage now https://t.co/idpexBIgNs