Madison Walder
@madastro.bsky.social
(She/her) | Astrophysics PhD student @Uni of Surrey | determined to yee some haws while I'm here ✨
Reposted by Madison Walder
*Taps mic* Is this thing on?
My first first-author paper has finally been published!
If you are like in globular clusters, dwarf galaxies, or a new third object we are calling "Globular Cluster-like Dwarfs" look no further!, we present high resolution simulations where all three emerge naturally🧪🔭
My first first-author paper has finally been published!
If you are like in globular clusters, dwarf galaxies, or a new third object we are calling "Globular Cluster-like Dwarfs" look no further!, we present high resolution simulations where all three emerge naturally🧪🔭
Today, our EDGE simulations are in Nature with the brilliant @astroeth.bsky.social paper on the formation of globular clusters, the clumps of ancient stars that have puzzled astronomers for centuries. Turns out to happen all by itself when you crank up the resolution. www.nature.com/articles/s41...
September 10, 2025 at 4:20 PM
*Taps mic* Is this thing on?
My first first-author paper has finally been published!
If you are like in globular clusters, dwarf galaxies, or a new third object we are calling "Globular Cluster-like Dwarfs" look no further!, we present high resolution simulations where all three emerge naturally🧪🔭
My first first-author paper has finally been published!
If you are like in globular clusters, dwarf galaxies, or a new third object we are calling "Globular Cluster-like Dwarfs" look no further!, we present high resolution simulations where all three emerge naturally🧪🔭
Reposted by Madison Walder
Big news! @astroeth.bsky.social has his Nature paper on the Emergence of Globular Clusters out today! His simulations have globulars forming naturally, as well as some cool globular cluster like dwarfs! Check it out! 🔭🧪☄️
www.nature.com/articles/s41...
www.nature.com/articles/s41...
The emergence of globular clusters and globular-cluster-like dwarfs - Nature
The results from a state-of-the-art suite of hydrodynamical cosmological zoom-in simulations show how globular clusters naturally emerge in the Standard Cosmology and also reveal the existence of a ne...
www.nature.com
September 10, 2025 at 4:24 PM
Big news! @astroeth.bsky.social has his Nature paper on the Emergence of Globular Clusters out today! His simulations have globulars forming naturally, as well as some cool globular cluster like dwarfs! Check it out! 🔭🧪☄️
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Madison Walder
Congrats to @desisurvey.bsky.social - it's looking more & more like dark energy isn't Einstein's cosmological constant! If you've woken up to the news & are searching for the publications, they don't appear to be on arxiv 🤷♀️ but they are online. 🔭 #cosmology 🧪
ℹ️: data.desi.lbl.gov/public/paper...
ℹ️: data.desi.lbl.gov/public/paper...
![A graph of the evolution of the dark energy (vertical axis) as a function of time (redshift on the horizontal axis) - showing an offset from the cosmological constant (a flat horizontal line). Here is the figure caption from the paper:
FIG. 12. Comparison of the constraints on the equation of
state of dark energy using the CPL parametrization and a bin-
ning reconstruction approach, using DESI+CMB+DESY5.
The solid green line shows the best-fit w(z) based on w0 and
wa inference and the green contours around it represent the
68% and 95% confidence intervals. We also show in blue the
constraints from the binning approach [47], with the hori-
zontal bars indicating the bin width (which is fixed) and the
vertical bars representing the 1σ error. Additionally, we in-
clude in gray the 1D posterior for each binning parameter.
The ΛCDM limit corresponds to the horizontal gray dashed
line.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:ok3ms3dzop7gcwejp7lswhpi/bafkreiaa64kyfu7u5ber7u6kwk2zzkuet66j6o3l4lr5ftl5sef67pzham@jpeg)
March 20, 2025 at 7:27 AM
Congrats to @desisurvey.bsky.social - it's looking more & more like dark energy isn't Einstein's cosmological constant! If you've woken up to the news & are searching for the publications, they don't appear to be on arxiv 🤷♀️ but they are online. 🔭 #cosmology 🧪
ℹ️: data.desi.lbl.gov/public/paper...
ℹ️: data.desi.lbl.gov/public/paper...
Reposted by Madison Walder
The European Space Agency's Euclid space telescope is assembling the largest 3D map of the universe ever made.
The first section is now complete. Take a look at what happens when you zoom in... 🧪🔭
www.esa.int/Science_Expl...
The first section is now complete. Take a look at what happens when you zoom in... 🧪🔭
www.esa.int/Science_Expl...
October 20, 2024 at 4:18 PM
The European Space Agency's Euclid space telescope is assembling the largest 3D map of the universe ever made.
The first section is now complete. Take a look at what happens when you zoom in... 🧪🔭
www.esa.int/Science_Expl...
The first section is now complete. Take a look at what happens when you zoom in... 🧪🔭
www.esa.int/Science_Expl...
Oof it’s been a while since I posted, but for those at #EAS2024, I have a (virtual) talk today at 15:54 CEST in the s7e session! Come along if you want to hear me ramble about how we can use stellar streams to probe the dark matter in galaxies! 🌌 🔭🧪
July 2, 2024 at 9:26 AM
Oof it’s been a while since I posted, but for those at #EAS2024, I have a (virtual) talk today at 15:54 CEST in the s7e session! Come along if you want to hear me ramble about how we can use stellar streams to probe the dark matter in galaxies! 🌌 🔭🧪
Reposted by Madison Walder
Great to have a talk on ESA’s Fast mission ARRAKIHS. Small missions get much less attention but deliver awesome science on shorter timescales and in a reasonable budget. #SPIEastro
June 17, 2024 at 2:53 AM
Great to have a talk on ESA’s Fast mission ARRAKIHS. Small missions get much less attention but deliver awesome science on shorter timescales and in a reasonable budget. #SPIEastro
Oh absolutely, there is definitely a correlation between the amount of time I’ve spent in academia and the degradation of my ability think/communicate coherently
Academics and other folks who do brain-work: do you have intervals where you're convinced you've permanently lost the ability to think & write at a high level? Asking for the obvious reason (I'm in one right now and am trying to convince myself it's more anxiety than reality)
May 25, 2024 at 10:00 AM
Oh absolutely, there is definitely a correlation between the amount of time I’ve spent in academia and the degradation of my ability think/communicate coherently
THATS 👏 MY 👏 SUPERVISOR 👏
For the Euclid release, I made a fun movie of the globular cluster M10 (NGC 6254) showing its tidal disruption in the Milky Way. The frames are every 100000 years so it’s fun to watch the stars in the outskirts of the cluster. We can detect the tidal distortion with Euclid 🔭 youtu.be/2VMycoO3oU8?...
May 23, 2024 at 4:15 PM
THATS 👏 MY 👏 SUPERVISOR 👏
Shout out to the sun for letting me check this off my bucket list
May 11, 2024 at 10:08 AM
Shout out to the sun for letting me check this off my bucket list
Perks of moving somewhere greener:
1) the rain makes the green more green™️
2) i am blessed by the presence of these little guys
1) the rain makes the green more green™️
2) i am blessed by the presence of these little guys
April 28, 2024 at 12:11 PM
Perks of moving somewhere greener:
1) the rain makes the green more green™️
2) i am blessed by the presence of these little guys
1) the rain makes the green more green™️
2) i am blessed by the presence of these little guys
Reposted by Madison Walder
At Indiana University. Admirable af.
April 26, 2024 at 4:54 PM
At Indiana University. Admirable af.
Crazy how this never happened to the preachers verbally assaulting students for wearing yoga pants on college campuses 🤔
Now that snipers are trained on peaceful students and professors are being hog-tied by masked men with assault rifles, it'd be great to hear from all the people who made "free speech on US campuses" their life's mission every time they met a student with blue hair.
April 26, 2024 at 1:05 PM
Crazy how this never happened to the preachers verbally assaulting students for wearing yoga pants on college campuses 🤔
We 👏 should 👏 talk 👏 more 👏 about 👏 streams 👏
The Rubin Observatory @vrubinobs.bsky.social
will use six different colour filters to detect stellar streams that are around five times more distant than is currently possible. Find out more: rubinobservatory.org/news/rubin-r... #astronomy
IMG: RubinObs/NOIRLab/NSF/AURA/J. daSilva, M. Zamani
will use six different colour filters to detect stellar streams that are around five times more distant than is currently possible. Find out more: rubinobservatory.org/news/rubin-r... #astronomy
IMG: RubinObs/NOIRLab/NSF/AURA/J. daSilva, M. Zamani
April 24, 2024 at 11:20 PM
We 👏 should 👏 talk 👏 more 👏 about 👏 streams 👏
Reposted by Madison Walder
It's #FeatureFriday! Meet Nora Shipp, stellar streams extraordinaire ✨
Stellar streams are the torn-apart remnants of small galaxies or star clusters around the Milky Way—they hold clues about its history, and the dark matter that surrounds it.
www.youtube.com/watc...
Stellar streams are the torn-apart remnants of small galaxies or star clusters around the Milky Way—they hold clues about its history, and the dark matter that surrounds it.
www.youtube.com/watc...
Rubin Observatory will Reveal Dark Matter’s Ghostly Disruptions of Stellar Streams - YouTube
In this video, Nora Shipp, Postdoctoral fellow at Carnegie Mellon University and Co-convener of the Dark Matter Working Group in the Rubin/LSST Dark Energy S...
www.youtube.com
April 19, 2024 at 10:49 PM
It's #FeatureFriday! Meet Nora Shipp, stellar streams extraordinaire ✨
Stellar streams are the torn-apart remnants of small galaxies or star clusters around the Milky Way—they hold clues about its history, and the dark matter that surrounds it.
www.youtube.com/watc...
Stellar streams are the torn-apart remnants of small galaxies or star clusters around the Milky Way—they hold clues about its history, and the dark matter that surrounds it.
www.youtube.com/watc...
Reposted by Madison Walder
Very excited to see my student Tariq Hilmi submit this paper https://arxiv.org/abs/2404.02953 with the S5 team. We explored how well we can recover subhalo properties from a realistic stream model. TLDR: we can do it pretty well for a 10^7 Msun perturbed even with present-day observables 1/ 🔭🧪
Inferring dark matter subhalo properties from simulated...
In the cold dark matter paradigm, our Galaxy is predicted to contain >10000 dark matter subhaloes in the $10^5-10^8M_\odot$ range which should be completely devoid of stars. Stellar streams are...
arxiv.org
April 5, 2024 at 10:46 AM
Very excited to see my student Tariq Hilmi submit this paper https://arxiv.org/abs/2404.02953 with the S5 team. We explored how well we can recover subhalo properties from a realistic stream model. TLDR: we can do it pretty well for a 10^7 Msun perturbed even with present-day observables 1/ 🔭🧪
Reposted by Madison Walder
The Event Horizon Telescope has measured the *polarized* radiation from our friendly neighborhood black hole, Sgr A*! Press release: eventhorizontelescope.org/blog/astrono..., papers in next skeet 🔭🧪
March 27, 2024 at 1:10 PM
The Event Horizon Telescope has measured the *polarized* radiation from our friendly neighborhood black hole, Sgr A*! Press release: eventhorizontelescope.org/blog/astrono..., papers in next skeet 🔭🧪
Reposted by Madison Walder
From the Astrobites collaboration: The genocide in Gaza demands our attention and our action. As astronomers and members of the global scientific community, we cannot ignore the immense suffering and devastation inflicted upon our colleagues. 🔭
astrobites.org/2024/03/27/a...
astrobites.org/2024/03/27/a...
Astrobites Statement on the Educational Siege in Gaza
The genocide in Gaza demands our attention and our action. As astronomers and members of the global scientific community, we cannot ignore the immense suffering and devastation inflicted upon our c…
astrobites.org
March 27, 2024 at 4:52 PM
From the Astrobites collaboration: The genocide in Gaza demands our attention and our action. As astronomers and members of the global scientific community, we cannot ignore the immense suffering and devastation inflicted upon our colleagues. 🔭
astrobites.org/2024/03/27/a...
astrobites.org/2024/03/27/a...
Reposted by Madison Walder
“Save Chandra” website now up with explanation of the budgetary threat to this Great Observatory, some necessary corrections regarding current mission capabilities and operating costs, and - most important - ways that you can help. 🧪 🔭 🛰️ Spread widely!
Act Now | Save the Chandra X-ray Observatory
Ask that Congress #SaveChandra! | The Chandra X-ray Observatory, one of
NASA's last Great Observatories, has revolutionized our understanding of
the Universe, mapped black holes across cosmic time, ...
www.savechandra.org
March 16, 2024 at 5:21 PM
“Save Chandra” website now up with explanation of the budgetary threat to this Great Observatory, some necessary corrections regarding current mission capabilities and operating costs, and - most important - ways that you can help. 🧪 🔭 🛰️ Spread widely!
MAGICAL
A Full Plankton Moon - ©
Petr Horálek /
Institute of Physics in Opava
- Photo
- HD Photo
- About Astronomy Picture Of the Day
#astrophotos
Maintained by @shinyakato.dev
🔭 READ MORE 🔭
Petr Horálek /
Institute of Physics in Opava
- Photo
- HD Photo
- About Astronomy Picture Of the Day
#astrophotos
Maintained by @shinyakato.dev
🔭 READ MORE 🔭
March 12, 2024 at 11:48 AM
MAGICAL
oh to be a tiny tree frog in a giant rainforest. no job, no insecurities, only wet.
March 6, 2024 at 12:17 PM
oh to be a tiny tree frog in a giant rainforest. no job, no insecurities, only wet.
Reposted by Madison Walder
there are a few fundamental rules that commuters absolutely MUST learn to survive in the UK. The first is to internalise the concept of "keep left" designed to help keep foot traffic efficient in both directions, then do your absolute best to do the exact OPPOSITE.
March 4, 2024 at 7:10 AM
there are a few fundamental rules that commuters absolutely MUST learn to survive in the UK. The first is to internalise the concept of "keep left" designed to help keep foot traffic efficient in both directions, then do your absolute best to do the exact OPPOSITE.
Reposted by Madison Walder
Paper alert! My student, Noushin Karim, has been searching for globular clusters around the M81 group dwarf galaxy, IC 2574. She has found 23 candidates, and 1 looks a bit Omega-Cen-like. 🔭🧪 arxiv.org/abs/2402.16955
February 28, 2024 at 9:52 AM
Paper alert! My student, Noushin Karim, has been searching for globular clusters around the M81 group dwarf galaxy, IC 2574. She has found 23 candidates, and 1 looks a bit Omega-Cen-like. 🔭🧪 arxiv.org/abs/2402.16955
It's paper day!!✨Very happy to announce that my first paper is (finally) on the arXiv today! Check it out if you want to find out how we can use stellar streams living in the outskirts of galaxies to learn about their dark matter halos! 🔭🧪 arxiv.org/abs/2402.13314
Probing the dark matter haloes of external galaxies with stellar streams
Stellar streams have proven to be powerful tools for measuring the Milky Way's gravitational potential and hence its dark matter halo. In the coming years, Vera Rubin, Euclid, ARRAKIHS, and NGRST...
arxiv.org
February 22, 2024 at 10:58 AM
It's paper day!!✨Very happy to announce that my first paper is (finally) on the arXiv today! Check it out if you want to find out how we can use stellar streams living in the outskirts of galaxies to learn about their dark matter halos! 🔭🧪 arxiv.org/abs/2402.13314
Can confirm Michelle is great!! Go apply!!!!
10 days left to apply for my open position! If you love dwarf galaxies and are on the job market, get in touch 🔭🧪✨
For those interested in a post-doctoral position working with me on dwarf galaxies, the job is also live on AAS now :) If you have any questions, please reach out 🔭🧪 jobregister.aas.org/ad/a807ca27
February 9, 2024 at 6:29 PM
Can confirm Michelle is great!! Go apply!!!!
Reposted by Madison Walder
After the Nancy Grace Roman Space Telescope launches—by May 2027—astronomers will use its images to explore what exists between looping tendrils of stars that are pulled from globular clusters to potentially reveal dark matter in greater detail than ever before: www.stsci.edu/contents/new...
January 24, 2024 at 6:13 PM
After the Nancy Grace Roman Space Telescope launches—by May 2027—astronomers will use its images to explore what exists between looping tendrils of stars that are pulled from globular clusters to potentially reveal dark matter in greater detail than ever before: www.stsci.edu/contents/new...