Weekly Update from the Open Journal of Astrophysics – 25/04/2026

So here we are again, on a Saturday morning, with another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further five papers, bringing the number in Volume 9 (2026) to 87 and the total so far published by OJAp up to 535.

I will continue to include the posts made on our Mastodon account (on Fediscience) to encourage you to visit it. Mastodon is a really excellent service, and a more than adequate replacement for X/Twitter (which nobody should be using); these announcements also show the DOI for each paper.

The first paper to report this week is “Bayesian Cosmic Void Finding with Graph Flows” by Leander Thiele (U. Tokyo, Japan). This was published on Monday 20th April in the folder Cosmology and Nongalactic Astrophysics. The paper presents a method using a deep graph neural network to identify cosmic voids in sparse galaxy surveys, improving upon traditional deterministic algorithms by considering the problem’s probabilistic nature. The overlay is here:

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

https://fediscience.org/@OJ_Astro/116435864086025246

The second paper for this week, published on Wednesday 22nd April in the folder Astrophysics of Galaxies, is “Sifting for a Stream: The Morphology of the 300S Stellar Stream” by Benjamin Cohen (U. Chicago, USA) and 20 others distributed around the world. This study analyzes the morphology of the $300S$ stellar stream, revealing three density peaks, a possible gap, and a kink, suggesting significant influence from the Large Magellanic Cloud on its structure.

The overlay for this one is here:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

https://fediscience.org/@OJ_Astro/116447005556180402

Next one up, the third paper of the week, is “IRMaGiC: Extending Luminous Red Galaxy Selection into the Infrared with Joint Rubin Observatory’s Large Survey of Space Time and Roman’s High Latitude Imaging Survey” by Zhiyuan Guo & Chris. W. Walter (Duke U., USA) and Eli S. Rykoff (Stanford U., USA) on behalf of the LSST Dark Energy Science Collaboration. This was published on Wednesday April 22nd in the folder Cosmology and Nongalactic Astrophysics. The paper introduces IRMaGiC, an algorithm that improves the selection and redshift estimation of Luminous Red Galaxies (LRGs) by incorporating infrared data, enhancing future cosmological surveys.

The overlay for this one is here:

The final, accepted version can be found on arXiv here and the Mastodon announcement is here:

https://fediscience.org/@OJ_Astro/116447067337351283

The fourth paper this week, published on Thursday April 23rd, is “The Diagnostic Temperature Discrepancy as Evidence for Non-Maxwellian Coronal Electrons” by Victor Edmonds (Final Stop Consulting, USA). This paper, in the folder Solar and Stellar Astrophysics, presents two methods of measuring electron temperature in the quiet solar corona yielding different results, suggesting non-Maxwellian electron velocity distributions may be responsible for the discrepancy.

The overlay is here:

The finally accepted version of this paper can be found here and the Mastodon announcement follows:

https://fediscience.org/@OJ_Astro/116452775389963618

The fifth and final paper for this week was published on Friday 24th April in the folder Astrophysics of Galaxies. The title is “Galaxy evolution in the post-merger regime. IV – The long-term effect of mergers on galactic stellar mass growth and distribution” by Sara L. Ellison (U. Victoria, Canada) and Leonardo Ferreira (Universidade Federal do Rio Grande, Brazil). This study uses a large sample of post-merger galaxies to demonstrate that galaxy mergers trigger significant and extended stellar mass growth in their central regions, independent of stellar population modelling.

The overlay is here:

You can find the authorized version of this paper on arXiv here and the Fediverse announcement is here:

https://fediscience.org/@OJ_Astro/116458316824739014

The overlay for this one is here:

You can find the officially-accepted version on arXiv here and the Mastodon announcement here:

https://fediscience.org/@OJ_Astro/116458316824739014

And that concludes this week’s update. I’ll do another one at the end of next week.

P.S. Thanks to the efforts of a member of our Editorial Board, the Open Journal of Astrophysics now has a Wikipedia page.

https://www.youtube.com/watch?v=yDAAlojz8NU

Kurzgesagt alimentando a mis pesadillas

#SpaceIsHard #SpaceIsScary #CosmicVoids #NightmareFuel #Science

Cosmic Voids: Where Dark Energy Dominates and Drives Universe Expansion

📰 Original title: Cosmic voids look empty but they may be tearing the universe apart

🤖 IA: It's clickbait ⚠️
👥 Usuarios: It's clickbait ⚠️

View full AI summary: https://killbait.com/en/cosmic-voids-where-dark-energy-dominates-and-drives-universe-expansion/?redirpost=6098156e-df6d-476b-b6f2-3200710c688c

#astronomy #cosmicvoids #darkenergy #universeexpansion

While the holy grail of #InhomogeneousCosmology is to explain #DarkEnergy as an epiphenomenon of the cosmologically recent formation epoch of #CosmicVoids and other #LargeScaleStructure, #YonadavBarryGinat and #PedroGFerreira have gone for a more modest goal: keeping the #CosmologicalConstant but tacking on void formation to get a sort-of #BeyondLCDM inhomogeneous model that better matches #DES and #DESI results [1].

#ArXiv_2601_20633
@cosmology #Cosmology #LCDM

[1] https://arxiv.org/abs/2601.20633

in the #arXiv

DESIVAST: A Catalog of Low-Redshift Voids using Data from the DESI DR1 Bright Galaxy Survey

by Hernan Rincon and co-authors
https://arxiv.org/abs/2411.00148

#Cosmology #Astronomy #Astrophysics #Astrodon #DESI #survey #DESIsurvey #galaxies #catalog #void #voids #cosmicvoids #voidfinder #SDSS #science #STEM #research

in the #arXiv

2D watershed void clustering for probing the cosmic large-scale structure

by Yingxiao Song and co-authors
https://arxiv.org/abs/2410.04898

#Cosmology #universe #voids #cosmicvoids #CosmicWeb #astronomy #astrophysics #astrodon #physics #space #science #research #STEM #watershed #clustering

Cosmography on the cover of Scientific American, with a feature article on cosmic voids

https://scientificamerican.com/issue/sa/2024/01-01/

#cosmology #cosmography #universe #astronomy #astrophysics #astrodon #space #science #research #void #voids #cosmicvoids #sciam #galaxies #cosmicweb

@civodul @khinsen

We use #CosmicVoids in [1][2], which in N-body sims are traced by low num-densities of particles => high noise. Full #Maneage controls + fixed seed rng's. We still have intramachine + (higher) intermachine randomness. Statistical upper limits to results OK. But still untraced sources of randomness.

Any clues for remaining randomness [2]?

#Reproducibility #ArXiv_2304_00591 #OpenScience

[1] Frozen record: https://zenodo.org/record/7792910

[2] Live git: https://codeberg.org/mpeper/lensing

#CosmicVoids should be detectable via their #GravitationalLensing effects.
Check this starting with a floppy-disk sized source snapshot [1].
#Reproducibility is via the #Maneage template of shell+make files.
Full research paper: [2][3][4][5]

[1] https://zenodo.org/record/7792910/files/lensing-e4f7af0-snapshot.tar.gz

[2] Preprint: https://arxiv.org/abs/2304.00591 #ArXiv_2304_00591

[3] Frozen record: https://zenodo.org/record/7792910

[4] Live git: https://codeberg.org/mpeper/lensing

[5] SWH: https://archive.softwareheritage.org/swh:1:rev:41507a706e16f04075c0c35853ddc226d3c72df5%3borigin=https://codeberg.org/mpeper/lensing

#Cosmology #OpenScience