Jiaxuan Li

218 posts

Jiaxuan Li banner
Jiaxuan Li

Jiaxuan Li

@AstroJacobLi

李嘉轩, graduate student at Princeton. Understand galaxies using telescopes and supercomputers.

Princeton, NJ Katılım Mayıs 2018
532 Takip Edilen453 Takipçiler
Sabitlenmiş Tweet
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
Please check out our discovery of a dwarf planet candidate that might challenge the Planet 9/Planet X hypothesis! Shout out to @SihaoCheng who discovered this object and Eritas Yang who really helped interpret its intriguing orbit.
Institute for Advanced Study (IAS)@the_IAS

🔭 RESEARCH NEWS: A small team, led by Sihao Cheng from the Institute’s School of Natural Sciences, has discovered a new trans-Neptunian object at the edge of our solar system that is potentially large enough to qualify as a dwarf planet, like Pluto: instituteforadvancedstudy.info/4kv8CLx

English
1
1
12
788
Jiaxuan Li retweetledi
NSF-DOE Rubin Observatory
NSF-DOE Rubin Observatory@VRubinObs·
Lights, camera, action! 🎬 The world's largest digital camera has been installed at NSF–DOE Rubin Observatory! 🤩 The LSST Camera was the final major component of the observatory. With it in place, Rubin officially enters its final phase of testing! 🔗: rubinobservatory.org/news/lsst-came…
English
7
68
180
10.8K
Jiaxuan Li retweetledi
NSF-DOE Rubin Observatory
NSF-DOE Rubin Observatory@VRubinObs·
Scrub a dub 🫧 ...except no scrubbing the delicate observatory optics! We don't use cloths or lens cleaner to clean the giant camera lenses. Instead, our summit staff use a high-speed stream of carbon dioxide "snow" to push debris off of the glass surface.
English
4
44
193
22.9K
Song Huang
Song Huang@dr_guangtou·
So I won this "Good Educator & Friend of the Students" award this year. I am deeply humbled by this recognition...but maybe I should choose a different photo if I know it is going to be used in the official announcement 😂
Song Huang tweet media
English
3
0
30
844
Astro Plot of the Week
Astro Plot of the Week@PlotAstro·
Speaking of the Olympiad, did you participate in an Astronomy Olympiad? I did! 🥈😀
English
6
0
13
2.4K
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
Wow!!
Yuan-Sen Ting 丁源森@TingAstro

The Payne just got a major upgrade. Led by @rozanski_t and his heroic and painstaking effort, the verdict is final -- Transformer-based emulators significantly outperform existing methods by capturing long-range spectral information. Bonus: We now include wavelength as input, allowing output spectra on any grid without predefined ranges—a game-changer for precision RV, binaries, or stellar mass black holes. Like in NLP, our Transformer model boasts: a) Better scaling with training steps and dataset size—more compute means continued improvement with no plateau in sight b) Improved interpretability—attention between tokens reveals clean representations of elemental species, showing the model learned to focus on transitions from the same species for better emulation. @rozanski_t has even more exciting ideas in the pipeline that didn't make it into this paper. Reach out to him and learn more!

QST
0
0
2
382
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
@yujing_qin No worries, I don't mind if you share it with me😝
English
0
0
0
96
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
@wcerny_astro Thanks for the idea! Actually we just got the g-band data with IMACS yesterday! I'll try to do a "standard" TRGB with those data and check the distance.
English
0
0
1
66
William (Will) Cerny
William (Will) Cerny@wcerny_astro·
@AstroJacobLi Awesome find and great work, Jiaxuan! I had a silly idea: out of curiosity, could you try a "single-band" TRGB? i.e., if you were to assume the brightest stars you see are giants at the tip and that M_i_TRGB ~ -4, do you recover roughly the same distance?
English
1
0
2
48
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
Paper day! We found a new quiescent dwarf galaxy that is very isolated. This galaxy "Hedgehog" has a stellar mass of ~10^6 Msun and is at a distance of 2.4 Mpc. This lonely little dwarf has *no neighbors* within 1 Mpc, and is not forming stars. 🌌✨ arxiv.org/abs/2406.00101
Jiaxuan Li tweet media
English
2
2
56
4K
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
This galaxy was discovered on May 1st, and the paper was submitted 30 days later! Thank you to Jenny, Scott, and @DanieliShany for making this happen! Thank you to the DELVE team whose data enabled this discovery, and @bmutlupakdil who generously helped us with follow-ups!
English
0
0
6
358
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
Hedgehog might be a backsplash galaxy from its nearest galaxy group CenA, but it could also be a reionization fossil. More observations (e.g., velocity, gas) are needed to pin down its origin and evolution history. Of course, it would be great to get SFH from HST or even JW!
Jiaxuan Li tweet media
English
1
0
3
309
Jiaxuan Li
Jiaxuan Li@AstroJacobLi·
@jwuphysics Thanks! Looking forward to catching up with you in the future!
English
0
0
1
60
John F. Wu
John F. Wu@jwuphysics·
Fantastic work finding another quiescent, isolated, dwarf galaxy! I'm sorry my visit to Princeton last week was so brief that I didn't get to hear about this wonderful result.
Jiaxuan Li@AstroJacobLi

Paper day! We found a new quiescent dwarf galaxy that is very isolated. This galaxy "Hedgehog" has a stellar mass of ~10^6 Msun and is at a distance of 2.4 Mpc. This lonely little dwarf has *no neighbors* within 1 Mpc, and is not forming stars. 🌌✨ arxiv.org/abs/2406.00101

English
2
1
6
809

Keşfet

@dr_guangtou @dartmouth @YBeletsky @ESO @PlotAstro @yujing_qin @wcerny_astro @elonmusk