Weekly Update from the Open Journal of Astrophysics – 13/09/2025
It’s Saturday again, so it’s time for another summary of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published seven new papers, which brings the number in Volume 8 (2025) up to 134, and the total so far published by OJAp up to 369. We seem to be emerging for the slight late-summer hiatus we have experienced over the last few weeks.
Anyway, the first paper to report this week is “Observing the Sun with the Atacama Large Aperture Submillimeter Telescope (AtLAST): Forecasting Full-disk Observations” by Mats Kirkaune & Sven Wedemeyer (U. Oslo, Norway), Joshiwa van Marrewijk (Leiden U., Netherlands), Tony Mroczkowski (ESO, Garching, Germany) and Thomas W. Morris (Yale, USA). This paper discusses possible strategies and parameters for full-disk observations of the Sun using the proposed Atacama Large Aperture Submillimeter Telescope (AtLAST). It was published on Tuesday 9th September 2025 in the folder Solar and Stellar Astrophysics.
The overlay is here:
You can make this larger by clicking on it. The officially accepted version of this paper can be found on the arXiv here.
The second paper this week, published on Wednesday 10th September in the folder Cosmology and NonGalactic Astrophysics, is “The exact non-Gaussian weak lensing likelihood: A framework to calculate analytic likelihoods for correlation functions on masked Gaussian random fields” by Veronika Oehl and Tilman Tröster (ETH Zurich, Switzerland). This paper shows how to calculate likelihoods for the correlation functions of spin-2 Gaussian random fields defined on the sphere in the presence of a mask with applications to weak gravitational lensing.
The overlay is here:
and you can find the final accepted version on arXiv here.
Next one up, the third paper this week, is “Subspace Approximation to the Focused Transport Equation. II. The Modified Form” by B. Klippenstein and Andreas Shalchi (U. Manitoba, Canada). This was also published on 10th September 2025 in the folder Solar and Stellar Astrophysics. It is about solving the focused transport equation analytically and numerically using the subspace method in two or more dimensions.
You can find the final accepted version on arXiv here.
The fourth paper of this week was also published on Wednesday 10th September. It is “Mass models of galaxy clusters from a non-parametric weak-lensing reconstruction” by Tobias Mistele (Case Western Reserve U., USA), Federico Lelli (INAF, Firenze, Italy), Stacy McGaugh (Case Western), James Schombert (U. Oregon, USA) and Benoit Famaey (Université de Strasbourg, France). Published in the folder Cosmology and NonGalactic Astrophysics, it presents new, non-parametric deprojection method for weak gravitational lensing applied to a sample of galaxy clusters. The overlay is here:
You can find the officially accepted version on arXiv here.
The fifth paper of the week is “A Swift Fix II: Physical Parameters of Type I Superluminous Supernovae” by Jason T. Hinkle & Benjamin J. Shappee (U. Hawaii, USA) and Michael A. Tucke (Ohio State, USA). This one was published on Thursday 11th September 2025 in the folder High-Energy Astrophysical Phenomena. The paper uses recalibrated Swift photometry to recompute peak luminosities and other properties of a sample of superluminous Type I supernovae. The overlay is here:
You can find the official accepted version on arXiv here.
Paper No. 6 for this week is “Detailed Microwave Continuum Spectra from Bright Protoplanetary Disks in Taurus” by Caleb Painter (Harvard, USA) and 11 others, too numerous to mention by name, based in the USA, Germany, Mexico and Taiwan. This one was published in the folder marked Solar and Stellar Astrophysics on September 11th 2025. It presents new observations sampling the microwave (4-360 GHz) continuum spectra from eight young stellar systems in the Taurus region. The overlay is here:
The final version can be found on arXiv here.
The last paper for this update is “On Soft Clustering For Correlation Estimators” by Edward Berman (Northeastern University, USA) and 13 others based in the USA, France, Denmark and Finland and Cosmos-Web:The JWST Cosmic Origins Survey. This was published on Friday 12th September 2025 in the folder Instrumentation and Methods for Astrophysics. It presents an algorithm for estimating correlations that clusters objects in a probabilistic fashion, enabling the uncertainty caused by clustering to be quantified simply through model inference. The overlay is here:
You can find the final version on arXiv here.
And that’s all the papers for this week. I’ve noticed a significant recent increase in the number of papers in Solar and Stellar Astrophysics, which means we’re broadening our impact across the community. Which is nice.
P.S. I found out last week that, according to NASA/ADS, papers in OJAp have now accumulated over 5000 citations.
#arXiv230903270v3 #arXiv240708718v2 #arXiv250406174v3 #arXiv250513145v2 #arXiv250613716v2 #arXiv250711801v2 #arXiv250721268v2 #AtacamaLargeApertureSubmillimeterTelescope #AtLAST #CorrelationFunctions #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #FocusedTransportEquation #galaxyClusters #InstrumentationAndMethodsForAstrophysics #MicrowaveSpectroscopy #OpenJournalOfAstrophysics #ProtoplanetaryDisk #protoplanetaryDisks #SolarAndStellarAstrophysics #solarObservations #Spin2Fields #StatisticalMethods #strongGravitationalLensing #SuperluminousSupernovae #SWIFT #TheOpenJournalOfAstrophysics #weakGravitationalLensing
Weekly Update from the Open Journal of Astrophysics – 12/07/2025
It’s Saturday morning again, so it’s time again for an update of papers published at the Open Journal of Astrophysics. Since the last update we have published seven new papers, which brings the number in Volume 8 (2025) up to 92, and the total so far published by OJAp up to 327.
This was a slightly strange week, starting with the fact that there were no new arXiv announcements on Monday 7th July because of the 4th July holiday in the USA on Friday so no papers were published that day. We were not able to publish any papers on Wednesday 9th July either because Crossref was offline for 24 hours that day while its data was migrated into the cloud. Our publishing process requires a live connection with Crossref to deposit metadata upon publication so we can’t publish while that service is down. Fortunately the update seems to have gone well and normal services resumed the following day. That partially accounts for the fact that four of this week’s papers were published on 10th July.
Anyway, The papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.
The first paper to report is “The Jackknife method as a new approach to validate strong lens mass models” by Shun Nishida & Masamune Oguri (Chiba University, Japan) , Yoshinobu Fudamoto (Steward Observatory, USA) and Ayari Kitamura (Tohoku University, Japan). This article, which is in the folder marked Cosmology and NonGalactic Astrophysics, describes and application of the Jackknife statistical resampling techique to gravitational lensing by removing lensed images and recalcualting the mass modelIt was published on Tuesday 8th July 2025. The overlay is here:
The officially-accepted version can be found on arXiv here.
The second paper is “Low redshift post-starburst galaxies host abundant HI reservoirs” by Sara Ellison (U. Victoria, Canada) and 10 others based in China, UK, Spain, USA and Canada. This one was also published oon Tuesday 8th July but in the folder Astrophysics of Galaxies. This paper uses 21cm observations of a sample of post-starburst galaxies, to show that they contain large reservoirs of neutral hydrogen. Here is the overlay:
You can find the final version of the manuscript on arXiv here.
Next one up, one of four published on Thursday 10th July, is “Predicting the number density of heavy seed massive black holes due to an intense Lyman-Werner field” by Hannah O’Brennan (Maynooth University, Ireland) and 7 others based in Ireland, USA and Italy. This paper presents an exploration of the scenario for black hole formation driven by Lyman-Werner photons (i.e. ultraviolet radiation in the range 11.2 to 13.6 eV). It is in the folder marked Cosmology and NonGalactic Astrophysics, and the overlay is here:
You can read the final accepted version on arXiv here.
The fourth paper this week, and the second published on 10th July, is “Chemical Abundances in the Metal-Poor Globular Cluster ESO 280-SC06: A Formerly Massive, Tidally Disrupted Globular Cluster” by Sam A. Usman (U. Chicago, USA) and 8 others based in the USA, Canada and Australia. This paper, which is in the folder Astrophysics of Galaxies, presents a detailed spectroscopic study of the chemical abundances in a Milky Way globular cluster ESO 280-SC06. The overlay is here:
The officially accepted version of the paper can be read here.
Next one up, also published on 10th July and also in the folder marked Astrophysics of Galaxies is “Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory” by Kabelo Tsiane (U. Michigan) and 9 others on behalf of the LSST Dark Energy Science Collaboration.
The overlay is here:
You can find the officially-accepted version of the paper on arXiv here.
The penultimate paper for this week, and the last of the batch published on 10th July, is “Systematically Measuring Ultra-Diffuse Galaxies. VIII. Misfits, Miscasts, and Miscreants” by Dennis Zaritsky, Richard Donnerstein, and Donghyeon J. Khim (Steward Observatory, U. Arizona, USA). This paper presents a morphological study of weird and wonderful galaxies as part of an effort to Systematically Measure Ultra-Diffuse Galaxies (the SMUDGes survey). It is in the folder marked Astrophysics of Galaxies. The overlay is here:
You can find the officially-accepted version of the paper on arXiv here.
The last article published this week is “Differential virial analysis: a new technique to determine the dynamical state of molecular clouds” by Mark R. Krumholz (ANU, Australia), Charles J. Lada (Harvard, USA) & Jan Forbrich (U. Herts, UK). This paper presents simple analytic models of supported and collapsing molecular clouds, tested using full 3D simulations and applied to observed clouds in Andromeda. It is in the folder marked Astrophysics of Galaxies and was published yesterday, i.e on Friday 11th July 2025. Here is the overlay
You can find the officially-accepted version on arXiv here.
And that’s all the papers for this week. I will, however, take this opportunity to mention that a while ago I was interviewed about the Open Journal of Astrophysics by Colin Stuart on behalf of the Foundational Questions Institute; the write-up of the interview can be found here.
#arXiv250116474v2 #arXiv250200574v2 #arXiv250303066v2 #arXiv250416203v2 #arXiv250500553v2 #arXiv250524755v2 #arXiv250615664v2 #AstrophysicsOfGalaxies #blackHoles #chemicalAbundances #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #DiamondOpenAccessPublishing #differentialVirialAnalysis #globularCluster #JackknifeResampling #LymanWernerRadiation #massiveBlackHoles #MilkyWay #OpenJournalOfAstrophysics #SMUDgesSurvey #StatelliteGalaxies #strongGravitationalLensing #TheOpenJournalOfAstrophysics #ultraDiffuseGalaxies #VeraCRubinObservatory
Weekly Update from the Open Journal of Astrophysics – 12/04/2025
Time for the weekly Saturday morning update of papers published at the Open Journal of Astrophysics. Since the last update we have published four new papers, which brings the number in Volume 8 (2025) up to 37 and the total so far published by OJAp up to 272.
In chronological order of publication, the four papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.
The first paper to report is “Searching for new physics using high precision absorption spectroscopy; continuum placement uncertainties and the fine structure constant in strong gravity” by Chung-Chi Lee (Big Questions Institute (BQI), Sydney, Australia), John K. Webb (Cambridge, UK), Darren Dougan (BQI), Vladimir A. Dzuba & Victor V. Flambaum (UNSW, Australia) and Dinko Milaković (Trieste, Italy).
This presents a discussion of the problem of continuum placement in high-resolution spectroscopy, which impacts significantly on fine structure constant measurements, and a method for mitigating its effects. The paper is in the folder Solar and Stellar Astrophysics and was published on Tuesday 8th April 2025. The overlay is here:
You can find the officially-accepted version of the paper on arXiv here.
The second paper to announce, also published on 8th April 2025, is “Deciphering Spatially Resolved Lyman-Alpha Profiles in Reionization Analogs: The Sunburst Arc at Cosmic Noon” by Erik Solhaug (Chicago, USA), Hsiao-Wen Chen (Chicago), Mandy C. Chen (Chicago), Fakhri Zahedy (University of North Texas), Max Gronke (MPA Garching, Germany), Magdalena J. Hamel-Bravo (Swinburne, Australia), Matthew B. Bayliss (U. Cincinatti), Michael D. Gladders (Chicago), Sebastián López (Universidad de Chile), Nicolás Tejos (Universidad Católica de Valparaíso, Chile).
This paper, which presents a study of the Lyman-alpha emission properties of a gravitationally-lensed galaxy at redshift z=2.37, appears in the folder Astrophysics of Galaxies. It was published
You can read the officially accepted version of this paper on arXiv here.
The third paper of the week is “On the progenitor of the type Ia supernova remnant 0509-67.5” by Noam Soker (Technion, Haifa, Israel). This one was published on Wednesday 9th April 2025 in the folder High-Energy Astrophysical Phenomena. The author discusses possible ideas for the origin of a supernova that exploded inside a planetary nebula.
Here is the overlay:
You can find the officially accepted version of this paper on arXiv here.
Last (but certainly) not least for this week, published on April 11th 2025, we have “Are Models of Strong Gravitational Lensing by Clusters Converging or Diverging?” by Derek Perera (U. Minnesota), John H Miller Jr & Liliya L. R. Williams (U. Minnesota, USA), Jori Liesenborgs (Hasselt U., Belgium), Allison Keen (U. Minnesota), Sung Kei Li (Hong Kong University), Marceau Limousin (Aix Marseille Univ., France). This papers study various models of a strong gravitational lensing system, the results suggesting that lens models are neither converging to nor diverging from a common solution for this system, regardless of method.
Here is the overlay:
The official published version can be found on the arXiv here.
That’s all the papers for this week. By way of a postscript I’ll just mention that the gremlins that have affected submissions to Crossref (which we rely on for registering the article metadata) have now been resolved and normal services have been restored.
#arXiv240910604v5 #arXiv241001849v2 #arXiv241105083v2 #arXiv250304709v2 #AstrophysicsOfGalaxies #CosmicNoon #DiamondOpenAccess #DiamondOpenAccessPublishing #fineStructureConstant #HighEnergyAstrophysicalPhenomena #HighResolutionSpectroscopy #PlanetaryNebula #reionization #SolarAndStellarAstrophysics #strongGravitationalLensing #SupernovaRemnant #TheOpenJournalOfAstrophysics
Another interesting strong lensing discovery by @NASAWebb : https://arxiv.org/abs/2504.03571
"if a bottom-heavy IMF for elliptical gals is employed, stellar mass estimations increase and can account for the majority of the lensing mass (up to ∼83\%), reducing the need for dark matter"!
We present the discovery, and initial lensing analysis, of a high-redshift galaxy-galaxy lensing system within the JWST-PEARLS/HST-TREASUREHUNT North Ecliptic Pole Time Domain Field (designated NEPJ172238.9+655143.1). The lensing geometry shears a $z=3.6\pm0.1$ star-forming galaxy into a near-Einstein ring with a radius of 0\farcs92, consisting of 4 primary images, around a foreground massive elliptical galaxy at $z=1.258\pm0.005$. The system is fortuitously located within the NIRISS F200W footprint of the PEARLS survey, enabling spectroscopic identification of the 8500A TiO band in the foreground galaxy and allowing tight constraints to be placed on the redshift of the background galaxy based on its continuum detection and lack of strong emission lines. We calculate magnification factors of $2.6<μ<8.4$ for the four images and a total lensing mass of $(4.08 \pm 0.07)\times10^{11}M_\odot$. SED fitting of the foreground elliptical galaxy within the Einstein radius reveals a stellar mass of $\sim1.26\times10^{11}M_\odot$, providing a mass/light ratio of 3.24. Employing simple scaling relations and assumptions, an NFW dark matter halo is found to provide the correct remaining mass within $0.12^{+0.21}_{-0.09}$dex. However, if a bottom-heavy IMF for elliptical galaxies is employed, stellar mass estimations increase and can account for the majority of the lensing mass (up to $\sim$83\%), reducing the need for dark matter. This system further demonstrates the new discovery space that the combined wavelength coverage, sensitivity and resolution of JWST now enables.
These results raise the question where we can track down dark matter? What do we know in the least model-dependent way?
For strong lensing, the question has an answer, look at this video for a recent summary:
https://youtu.be/5FyaoYsCSVg?si=zmokA8g3XPCkoQwF
#astrophysics #astronomy #StrongGravitationalLensing #Cosmology #DarkMatter
2) the Bullet cluster is a more complicated structure than a binary system of two big dark-matter clumps that are offset to the baryons:
arxiv.org/abs/2503.21870
Masses were reduced and bounds on SIDM were set. Looks like we need less dark matter if the structure is more complex!
...and there is also a method to constrain dark matter properties purely from the multiple images, see this NASA press release for more:
https://science.nasa.gov/missions/hubble/double-galaxy-mystifies-hubble-astronomers/
#astrophysics #astronomy #StrongGravitationalLensing #Cosmology #DarkMatter
Today was progress-day for lensing!
1) A1689 at z=0.183 is elongated along the line of sight:
arxiv.org/abs/2503.22316
I hope there will be studies of A3827, too. The latter is only at z=0.1 and it seems that the thickness also affects the strong lensing effects:
arxiv.org/abs/2306.11779
#astrophysics #astronomy #StrongGravitationalLensing #Cosmology #DarkMatter
That's quite an interesting read today: new lensing survey data released with 100 strong-lensing galaxy-scale cases:
https://arxiv.org/abs/2503.08777
https://arxiv.org/abs/2503.08782
https://arxiv.org/abs/2503.08785 (congrats @astronat !)
We present the COSMOS-Web Lens Survey (COWLS), a sample of over 100 strong lens candidates from the $0.54$\,deg$^2$ COSMOS-Web survey, discovered using exquisite James Webb Space Telescope (JWST) imaging across four wavebands. Following two rounds of visual inspection, over 100 candidates were ranked as `high confidence' or `likely' by at least $50\%$ of inspectors. The COWLS sample has several notable properties: (i) magnified source galaxies spanning redshifts $z \sim 0.1$ to $z \sim 9$, which therefore extend into the epoch of reionisation; (ii) the highest-redshift lens galaxies known, pushing galaxy density profile evolution studies beyond $z \sim 2$; (iii) all lenses are distributed within a contiguous $0.54$\,deg$^2$ region, allowing for joint strong and weak lensing analyses; and (iv) a subset exhibits lensed source emission ray-traced near the lens galaxy centers, enabling studies of supermassive black holes and dust absorption. A key innovation of our approach is the use of lens modelling to aid in identifying lenses that may otherwise be missed. This paper is accompanied by the first COWLS public release, providing JWST NIRCam imaging in four bands, lens models, pixelized source reconstructions and lens redshift estimates : https://github.com/Jammy2211/COWLS_COSMOS_Web_Lens_Survey
Through a wine glass, darkly…
Usually I disapprove of using a wine glass for any purpose other than drinking wine, but here’s a very neat short video by Phil Marshall explaining how you can use a one to simulate a strong gravitational lens such as the system that produced the wonderful Einstein ring recently discovered by Euclid. More specifically it shows how perfect alignment leads to a ring whereas other configurations can produce multiple images or arcs.
https://www.youtube.com/watch?v=IXfUk4Eltkg
If you’re planning to try this at home, please remember to empty your glass beforehand.
#Euclid #PhilMarshall #strongGravitationalLensing #wineGlass
German Virtual Observatory
In the Dark
Gravity Grinch
