Weekly Update from the Open Journal of Astrophysics – 09/05/2026

It’s Saturday once again, so time for 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 99 and the total so far published by OJAp up to 547. We didn’t quite make it to a hundred for the year last week, but will do so with the next paper.

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 “Formation of Close Binaries through Massive Black Hole Perturbations and Chaotic Tides” by Howard Hao-Tse Huang and Wenbin Lu (University of California at Berkeley, USA). This one was published on Wednesday 6th May 2026 in the folder Astrophysics of Galaxies. The paper presents a model of massive black hole-binary systems, showing that repeated tidal interactions can lead to the creation of hyper-velocity stars and other nuclear transients.

The overlay for this paper is here

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

https://fediscience.org/@OJ_Astro/116526323790020433

The second paper for this week, also Wednesday 6th May, but in the folder Cosmology and Nongalactic Astrophysics is “Detection of supernova magnitude fluctuations induced by large-scale structure” by Andrew Nguyen (Swinburne Institute of Technology, Australia) and 58 others based all around the world. This study uses supernovae and galaxy velocities to measure the universe’s structure growth rate, confirming the Planck LambdaCDM model prediction. The methodology is validated and shows potential for future research.

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/116526449130876366

Next one up, the third paper of the week, also published on Wednesday 6th May in the folder Cosmology and Nongalactic Astrophysics is “Comparing cosmic shear nulling methods for Stage-IV surveys” by Naomi Clare Robertson and Alex Hall (University of Edinburgh, UK). This study compares three strategies for reducing baryon feedback impact on cosmic shear measurements. All methods effectively mitigate bias, with varying degrees of efficiency and information preservation.

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/116526251813375105

The fourth paper this week, published on Thursday May 7th, is “Egent: An Autonomous Agent for Equivalent Width Measurement” by Yuan-Sen Ting & Serat Mahmud Saad (Ohio State University, USA), Fan Liu (National Astronomical Observatories, Beijing, China), and Yuting Shen (Georgia Institute of Technology, USA). Egent is an autonomous agent that combines multi-Voigt profile fitting with large language model visual inspection for efficient, automated analysis of raw flux spectra, validated against expert measurements. This one is in the folder Instrumentation and Methods for Astrophysics. The associated software can be found here.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116531924397498394

The fifth and final article of this week was published on Friday 8th May in the folder Astrophysics of Galaxies. The title is “DiffstarPop: A generative physical model of galaxy star formation history” and it is by Alex Alarcon (Institute of Space Sciences, Barcelona, Spain), Andrew P. Hearin , Matthew R. Becker & Gillian Beltz-Mohrmann (Argonne National Laborarory, USA), and Andrew Benson & Sachi Weerasooriya (Carnegie Observatories, USA). DiffstarPop is a model that accurately and rapidly reproduces statistical distributions of galaxy star formation histories (SFH), using parameters related to galaxy formation physics.

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/116537709130989142

Here endeth this week’s update. There shall be another next Saturday.

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

#arXiv251007673v2 #arXiv251027604v3 #arXiv251111965v2 #arXiv251201270v2 #arXiv251215604v2 #AstrophysicsOfGalaxies #BaryonicFeedback #blackHoleBinaries #cosmicShear #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #DiamondOpenAccessPublishing #Egent #EquivalentWidth #galaxyEvolution #hyperVelocityStars #InstrumentationAndMethodsForAstrophysics #nuclearTransients #OpenAccess #OpenAccessPublishing #peculiarVelocities #supernovae #VoigtProfiles #weakGravitationalLensing

Wow 98,000 peculiar velocities

The DESI DR1 Peculiar Velocity Survey: Fundamental Plane Catalogue
by C.E. Ross and co-authors
https://arxiv.org/abs/2512.03226

For comparison: the Great Attractor was discovered with 400 PVs, Laniakea with 8000 PVs, South Pole Wall with 18,000 PVs

#Cosmicflows #Cosmology #DESI #Laniakea #GreatAttractor #SouthPoleWall #science #news #astrodon #arXiv #galaxies #peculiarvelocities

The velocity field in the local supercluster.

A Local Supercluster velocity field model is considered which includes galaxy deceleration by spherically symmetric density enhancement and Local Group random motion with respect to nearby galaxies, and whose free parameters are adjusted to minimize scatter about the IR luminosity-H I velocity width relation. This adjustment yields a best estimate for the amplitude of the deceleration pattern at the Local Group position of 250 + or - 64 km/sec, and a total velocity toward the Virgo cluster of 331 + or - 41 km/sec. Potential systematic errors have been minimized through the selective pruning of the sample used, and Monte Carlo experiment calibration of the remaining systematic errors. A significant reduction in residual amplitudes is found upon testing for differential rotation about the center of the Supercluster. The derived total velocity with respect to the Supercluster shows better agreement with the velocity inferred from the 3 K background dipole anisotropy than has been previously obtained.

NASA/ADS

Introducing the Mass Hyperplane (MH), to measure the peculiar velocities of 2496 galaxies at z < 0.12 from the GAMA sample

by Mustafa Burak Dogruel and co-authors
https://arxiv.org/abs/2405.10866

#Cosmology #galaxies #MassHyperplane #TullyFisher #FundamentalPlane #cosmicflows #PeculiarVelocities #Hubble #HubbleConstant #GAMA #arXiv #astroph #astronomy #astrophysics #astrodon #science #STEM

Galaxy And Mass Assembly (GAMA): Stellar-to-Dynamical Mass Relation II. Peculiar Velocities

Empirical correlations connecting starlight to galaxy dynamics (e.g., the fundamental plane (FP) of elliptical/quiescent galaxies and the Tully--Fisher relation of spiral/star-forming galaxies) provide cosmology-independent distance estimation and are central to local Universe cosmology. In this work, we introduce the mass hyperplane (MH), which is the stellar-to-dynamical mass relation $(M_\star/M_\mathrm{dyn})$ recast as a linear distance indicator. Building on recent FP studies, we show that both star-forming and quiescent galaxies follow the same empirical MH, then use this to measure the peculiar velocities (PVs) for a sample of 2496 galaxies at $z<0.12$ from GAMA. The limiting precision of MH-derived distance/PV estimates is set by the intrinsic scatter in size, which we find to be $\approx$0.1~dex for both quiescent and star-forming galaxies (when modeled independently) and $\approx$0.11~dex when all galaxies are modeled together; showing that the MH is as good as the FP. To empirically validate our framework and distance/PV estimates, we compare the inferred distances to groups as derived using either quiescent or star-forming galaxies. A good agreement is obtained with no discernible bias or offset, having a scatter of $\approx$0.05~dex $\approx$12\% in distance. Further, we compare our PV measurements for the quiescent galaxies to the previous PV measurements of the galaxies in common between GAMA and the Sloan Digital Sky Survey (SDSS), which shows similarly good agreement. Finally, we provide comparisons of PV measurements made with the FP and the MH, then discuss possible improvements in the context of upcoming surveys such as the 4MOST Hemisphere Survey (4HS).

arXiv.org