Pengfei Li
@pengfeili.bsky.social
Assistant professor at Nanjing University. Humboldt fellow previously @AIP. Work on dynamics of galaxies and galaxy clusters.
Pinned
A (dark matter) Space Oddity:
We have an exciting new paper led by @pengfeili.bsky.social: arxiv.org/abs/2511.17705
He used the best data on the Milky Way rotation curve from Gaia to infer not the current, but the *primordial* dark-matter halo of the Galaxy.
And it is quite odd. 🧪🔭☄️
1/6
We have an exciting new paper led by @pengfeili.bsky.social: arxiv.org/abs/2511.17705
He used the best data on the Milky Way rotation curve from Gaia to infer not the current, but the *primordial* dark-matter halo of the Galaxy.
And it is quite odd. 🧪🔭☄️
1/6
The odd primordial halo of the Milky Way implied by Gaia. A shallow core, but a steep decline
Primordial dark matter halos are well understood from cold dark matter-only simulations. Since they can contract significantly as baryons settle into their centers, direct comparisons with observed ga...
arxiv.org
Please check the great summary of our new paper, inferring the primordial dark matter halos from observations.
Here is the press release.
Nanjing Univ. press release: Our Galaxy’s Primordial Dark Matter Halo is a Major Oddity
astronomy.nju.edu.cn/EN/NewsEvent...
Article by Li et al.: www.aanda.org/10.1051/0004...
astronomy.nju.edu.cn/EN/NewsEvent...
Article by Li et al.: www.aanda.org/10.1051/0004...
天文与空间科学学院 News & Events
Scientists reverse-engineer our Galaxy’s primordial dark matter halo for the first time, and it is nothing like cold dark matter halos.
astronomy.nju.edu.cn
November 27, 2025 at 3:37 AM
Here is the press release.
Please check the great summary of our new paper, inferring the primordial dark matter halos from observations.
A (dark matter) Space Oddity:
We have an exciting new paper led by @pengfeili.bsky.social: arxiv.org/abs/2511.17705
He used the best data on the Milky Way rotation curve from Gaia to infer not the current, but the *primordial* dark-matter halo of the Galaxy.
And it is quite odd. 🧪🔭☄️
1/6
We have an exciting new paper led by @pengfeili.bsky.social: arxiv.org/abs/2511.17705
He used the best data on the Milky Way rotation curve from Gaia to infer not the current, but the *primordial* dark-matter halo of the Galaxy.
And it is quite odd. 🧪🔭☄️
1/6
The odd primordial halo of the Milky Way implied by Gaia. A shallow core, but a steep decline
Primordial dark matter halos are well understood from cold dark matter-only simulations. Since they can contract significantly as baryons settle into their centers, direct comparisons with observed ga...
arxiv.org
November 27, 2025 at 3:32 AM
Please check the great summary of our new paper, inferring the primordial dark matter halos from observations.
Reposted by Pengfei Li
New press release about our new paper led by my PhD student Mariana Pouseiro Júlio! 🔭🧪☄️
English version here: www.aip.de/en/news/dark...
English version here: www.aip.de/en/news/dark...
October 27, 2025 at 10:45 AM
New press release about our new paper led by my PhD student Mariana Pouseiro Júlio! 🔭🧪☄️
English version here: www.aip.de/en/news/dark...
English version here: www.aip.de/en/news/dark...
Reposted by Pengfei Li
Paper day! My PhD student Mariana Júlio, with @readdark.bsky.social, @pengfeili.bsky.social and others, studies the internal dynamics of dwarf galaxies and finds they don't agree with the Radial Acceleration Relation, challenging the dark matter alternative MOND.
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
The radial acceleration relation at the EDGE of galaxy formation: testing its universality in low-mass dwarf galaxies
A tight correlation between the baryonic and observed acceleration of galaxies has been reported over a wide range of mass ($10^8 < M_{\rm bar}/{\rm M}_\odot < 10^{11}$) - the Radial Acceleration Rela...
arxiv.org
October 9, 2025 at 8:55 AM
Paper day! My PhD student Mariana Júlio, with @readdark.bsky.social, @pengfeili.bsky.social and others, studies the internal dynamics of dwarf galaxies and finds they don't agree with the Radial Acceleration Relation, challenging the dark matter alternative MOND.
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
arxiv.org/abs/2510.06905
🔭☄️🧪
1/7
Reposted by Pengfei Li
Jamie‘s new Nature Astronomy paper on how M31‘s satellite galaxy system is much more asymmetric than typically expected from cosmological simulations is now out on the arXiv, too. 🔭
arxiv.org/abs/2504.08047
arxiv.org/abs/2504.08047
Andromeda's asymmetric satellite system as a challenge to cold dark matter cosmology
The Andromeda galaxy is surrounded by a strikingly asymmetrical distribution of satellite dwarf galaxies aligned towards the Milky Way. The standard model of cosmology predicts that most satellite gal...
arxiv.org
April 14, 2025 at 6:55 AM
Jamie‘s new Nature Astronomy paper on how M31‘s satellite galaxy system is much more asymmetric than typically expected from cosmological simulations is now out on the arXiv, too. 🔭
arxiv.org/abs/2504.08047
arxiv.org/abs/2504.08047
#Paperday New paper accepted by A&A on the mass measurements and comparisons for eROSITA clusters is available at arxiv.org/abs/2411.09735. One result that might be particularly useful is the spatially resolved mass-velocity dispersion relation. A thread summarizes the paper.
November 18, 2024 at 2:56 PM
#Paperday New paper accepted by A&A on the mass measurements and comparisons for eROSITA clusters is available at arxiv.org/abs/2411.09735. One result that might be particularly useful is the spatially resolved mass-velocity dispersion relation. A thread summarizes the paper.
Reposted by Pengfei Li
Now out: Episode 3 of the dwarf galaxies and cosmology video series produced by AIP PhD students Mariana P. Júlio and Jamie K. Kanehisa. This one interviews Paris Observatory's Yanbin Yang and AIP's Humboldt Fellow @pengfeili.bsky.social on the topic of Dark Matter.
www.youtube.com/watch?v=Z6IU...
www.youtube.com/watch?v=Z6IU...
Dark Matter • IAUS379 | Dr. Pengfei Li & Dr. Yanbin Yang
Dr. Pengfei Li, postdoctoral researcher at the Leibniz Institute for Astrophysics Potsdam (AIP), Germany, and Dr. Yanbin Yang from the Paris Observatory, Fra...
www.youtube.com
February 6, 2024 at 2:28 PM
Now out: Episode 3 of the dwarf galaxies and cosmology video series produced by AIP PhD students Mariana P. Júlio and Jamie K. Kanehisa. This one interviews Paris Observatory's Yanbin Yang and AIP's Humboldt Fellow @pengfeili.bsky.social on the topic of Dark Matter.
www.youtube.com/watch?v=Z6IU...
www.youtube.com/watch?v=Z6IU...
Reposted by Pengfei Li
Check out Ep2 of the interview series on dwarf galaxies, the Local Group & cosmology, shot at our IAU symposium. 🔭🧪 This one interviews the fantastic Tony Sohn about measuring the motion of galaxies. Produced by AIP PhD students J.K. Kanehisa & M.P. Júlio [email protected] youtu.be/vTAbQw78GIE
Measuring the motion of galaxies • IAUS379 | Dr. Tony Sohn
Dr. Tony Sohn from the Space Telescope Science Institute, USA, talks about measuring the motion of galaxies that are millions of light years away and of star...
youtu.be
January 11, 2024 at 11:59 AM
Check out Ep2 of the interview series on dwarf galaxies, the Local Group & cosmology, shot at our IAU symposium. 🔭🧪 This one interviews the fantastic Tony Sohn about measuring the motion of galaxies. Produced by AIP PhD students J.K. Kanehisa & M.P. Júlio [email protected] youtu.be/vTAbQw78GIE
Reposted by Pengfei Li
Want to learn about astrophysics from international experts? 🔭🧪 Check out this new series of interviews shot at our IAU Symposium #IAUS379. The first video on "Dwarf Galaxies" featuring the fantastic @runningastronomer.bsky.social is online now (next one in January):
www.youtube.com/watch?v=iQJI...
www.youtube.com/watch?v=iQJI...
The smallest galaxies in the Universe • IAUS379 | Dr. Michelle Collins
Dr. Michelle Collins, University of Surrey, UK, answers questions on dwarf galaxies, the smallest and most abundant galaxies in the Universe. Discover what t...
www.youtube.com
December 13, 2023 at 1:12 PM
Want to learn about astrophysics from international experts? 🔭🧪 Check out this new series of interviews shot at our IAU Symposium #IAUS379. The first video on "Dwarf Galaxies" featuring the fantastic @runningastronomer.bsky.social is online now (next one in January):
www.youtube.com/watch?v=iQJI...
www.youtube.com/watch?v=iQJI...