In the Dark2d ago

Weekly Update from the Open Journal of Astrophysics – 06/06/2026

Another Saturday, 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 119 and the total so far published by OJAp up to 567.

I will continue to include the posts made on our Mastodon account (on Fediscience); these announcements also show the DOI for each paper.

The first paper to report this week, published on Tuesday 2nd June, is “The impact of the formation channel on gravitational-wave-galaxy cross-correlations” by Kabir Chakravarti (Chennai Mathematical Institute, India) and Federico R Urban (CEICO-FZU, Czech Republic). This article, published in the folder Cosmology and Nongalactic Astrophysics, explores how uncertainties in binary formation affect the cross-correlation signal between gravitational wave events and galaxy catalogues, finding that time-delay distribution significantly impacts the signal.

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/116679308847047911

The second paper for this week, also published on Tuesday 2nd June but in the folder High-Energy Astrophysical Phenomena, is “Transient X-ray Sources as Extremely Eccentric Mass-Transfer Binaries with Compact Companions” by Jonathan I Katz and Michael A Nowak (Washington University, St Louis, USA). This article suggests that X-ray transients, similar to tidal disruption events, are produced in eccentric stellar-compact object binaries, with their frequency gradually increasing over time.

The overlay for this one looks like this:

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

https://fediscience.org/@OJ_Astro/116679395198117735

Next one up, the third paper of the week, also published on Tuesday 2nd June in the folder High-Energy Astrophysical Phenomena is “Resolving the (Debate About) Nozzle Shocks in Tidal Disruption Events” by Zachary L. Andalman & Eliot Quataert (Princeton U., USA), Eric R. Coughlin (Syracuse U. USA) and C. J. Nixon (U. Leeds, UK). This paper presents a model to understand the role of nozzle shocks in the circularization of stellar debris during a tidal disruption event when a star approaches a supermassive black hole (SMBH)

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/116679426224933831

The fourth paper this week, published on Wednesday 3rd June in the folder Cosmology and Nongalactic Astrophysics, is “Validating Digital Twins of the Local Universe with the Thermal Sunyaev-Zel’dovich Signal” by Richard Stiskalek (University of Oxford, UK) and Harry Desmond (University of Portsmouth, UK). The thermal Sunyaev-Zel’dovich effect and constrained simulations are used to analyze the thermal pressure of ionized gas in galaxy clusters and produce a set of digital twins for cosmological study.

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/116684470440285496

The fifth and final paper this week, published on Thursday 4th June in the folder Cosmology and Nongalactic Astrophysics is “Photon (Non)Conservation in the Reduced Speed of Light Approximation and How to (Almost) Fix It” by Nickolay Y. Gnedin (University of Chicago, USA). The “Reduced Speed of Light” approximation in cosmological simulations can lead to photon non-conservation, and while some missing photons can be counted, adding them back is challenging.

The overlay for this one is here:

The officially accepted version of this paper can be found on arXiv here and Mastodon announcement here

https://fediscience.org/@OJ_Astro/116691566968428861

And that concludes this week’s update. I’ll do another one next Saturday.

#arXiv251202094v2 #arXiv251208928v2 #arXiv260115935v2 #arXiv260214825v2 #arXiv260223474v2 #BayesianOriginReconstructionFromGalaxies #BinaryBlackHoles #BORG #cosmologicalSimulations #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #DiamondOpenAccessPublishing #gravitationalWaves #HighEnergyAstrophysicalPhenomena #massTransferBinaries #nozzleShocks #OpenAccess #OpenAccessPublishing #reducedSpeedOfLightApproximation #supermassiveBlackHoles #thermalSunyaevZeldovichEffect #tidalDisruptionEvent #XRayTransients
MPI for Gravitational Physics3d ago

Only one month left! On July 4th the 11th Open Day at our gravitational-wave detector GEO600 will take place.

ℹ️ https://www.geo600.org/openday2026

Just drop by GEO600 south of Hanover, Germany, between 12:00 and 16:00 CEST, talk to our researchers, and get insights into a cutting-edge research facility.

P.S.: Last chance to see! This Open Day will be the last as GEO600 will cease operations at the end of this year.

#SciComm #Astronomy #GravitationalWaves #Hanover #Sarstedt

MPI for Gravitational PhysicsJun 1

📣 New title image 🖼️

The image shows the spectrograms of all loud gravitational-wave events from the observing run O4b, which are listed in the new GWTC-5.0 catalog.

Researchers at the @mpi_grav contribute to discoveries in the largest gravitational-wave catalog ever compiled.

➡️ https://www.aei.mpg.de/1449649/the-new-lig

GWTC-5 is the largest gravitational-wave catalog, with 161 new events, totaling 390 confirmed detections since 2015.

Picture: Derek Davis / University of Rhode Island / LIGO-Virgo-KAGRA

#GWTC5 #GravitationalWaves #BlackHoles #Astrophysics #Astrodon #Astronomy

MPI for Gravitational PhysicsMay 28

👉 Unser Tipp für dieses (und die kommenden) Wochenende(n) in Berlin ✨

„nach unten biegen - eine Ausstellung an den Grenzen von Wissenschaften und Künsten zur Schwerkraft“ in der Ruine der Künste Berlin

🚩 Hittorfstr. 5, 14195 Berlin-Dahlem

📅 Eröffnung der Ausstellung: 31. Mai 15-18 Uhr

📅 danach immer samstags und sonntags bis 26. Juli zwischen 15 und 18 Uhr geöffnet

#Wissenschaft #Physik #Science #Physics #Kunst #Berlin #MastoArt #Gravitationswellen #GravitationalWaves

MPI for Gravitational PhysicsMay 27

The new LIGO-Virgo-KAGRA catalog sets records in precision gravitational-wave astronomy – Researchers at the @mpi_grav contribute to discoveries in the largest gravitational-wave catalog ever compiled.

➡️ https://www.aei.mpg.de/1449649/the-new-ligo-virgo-kagra-catalog-sets-records-in-precision-gravitational-wave-astronomy

The @LIGO Virgo KAGRA collaboration releases the largest gravitational-wave catalog, GWTC-5, with 161 new events, totaling 390 confirmed detections since 2015.

The catalog contains many astrophysical highlights: the gravitational-wave source with the most precise sky localization, the first measurement of three gravitational-wave tones from a black hole, evidence for the existence of second-generation black holes, and new measurements of how fast the Universe is expanding.

Picture: Derek Davis / University of Rhode Island / LIGO-Virgo-KAGRA

#GWTC5 #GravitationalWaves #BlackHoles #Astrophysics #Astrodon #Astronomy

Daniel FischerMay 23
Thick Lunar Crust Amplifies Deci-Hertz Gravitational-Wave Signal: https://arxiv.org/abs/2601.16567 -> We’re Going to Steal the Moon (For #GravitationalWaves): https://astrobites.org/2026/05/23/were-going-to-steal-the-moon-for-gravitational-waves/
Thick Lunar Crust Amplifies Deci-Hertz Gravitational-Wave Signal

Gravitational waves (GWs) in the $0.01\sim1$ Hz band encode unique signatures of the early universe and merging compact objects, but they are beyond the reach of existing observatories. Theoretical models suggest that the Moon could act as a resonant detector, but the unknown influence of its rugged surface and heterogeneous interior poses a challenge to the accurate modeling of its response. Here, we address this long-standing uncertainty by constructing the first high-resolution, two-dimensional model of the lunar GW response, more realistic than previous ones. We achieve this by combining high-fidelity spectral-element simulations with the analytical power of normal-mode perturbation theory, thereby resolving topographical effects down to 2 km grid spacing while maintaining the capacity to discern global free-oscillation patterns. This dual-methodology approach not only recovers the expected predominant quadrupole ($l=2$) oscillation mode, but also exposes a systematic signal amplification in thick-crust regions. This enhancement is traced by our normal-mode analysis to a mode-coupling process, in which the original quadrupolar oscillation induced by the passing GW distributes energy into a series of higher-order modes, the hybridized eigenmodes of a laterally heterogeneous Moon. In certain narrow frequency ranges, we observe up to tenfold amplification spanning into the deci-hertz band, highlighting the power of numerical simulations in resolving these structurally fine-tuned features for designing future detectors. Our work establishes the Moon as a resonant GW detector albeit its complex topographical structures, and the resulting amplification maps provide quantitative guide for the optimal landing site selection.

arXiv.org
Miro CollasMay 22

Possible Detection of Dark Matter in a Black Hole Collision Event - YouTube
https://www.youtube.com/watch?v=noI0HE-7c-A

#Astronomy #Cosmology #GravityWaves #GravitationalWaves #DarkMatter #BlackHoles

Possible Detection of Dark Matter in a Black Hole Collision Event

YouTube
Byte-PulseMay 18

🔬 Massive Black Holes Grow Differently, Study Finds

Forget what you thought about massive black holes. New Cardiff University research says they're not from collapsing stars, but cosmic collisions. Big shake-up for astronomy.

https://byte-pulse.net/article/massive-black-holes-grow-differently-study-finds

#blackholes #astronomy #gravitationalwaves #cosmology

Daniel FischerMay 15
Scalar fields around black hole binaries in LIGO-Virgo-KAGRA: https://arxiv.org/abs/2510.17967 -> A new way to spot signs of dark matter: https://news.mit.edu/2026/new-way-spot-signs-dark-matter-0512 - #GravitationalWaves emitted by colliding #BlackHoles may bear imprints of #DarkMatter, which physicists could detect with a new model.
Scalar fields around black hole binaries in LIGO-Virgo-KAGRA

Light scalar particles arise naturally in many extensions of the Standard Model and are compelling dark-matter candidates. Gravitational interactions near black holes can trigger the growth of dense scalar configurations that, if sustained during inspiral, alter binary dynamics and imprint signatures on gravitational-wave signals. Detecting such effects would provide a novel probe of fundamental physics and dark matter. Here we develop a semi-analytic waveform model for binaries in scalar environments, validate it against numerical relativity simulations, and apply it in a Bayesian analysis of the LIGO-Virgo-KAGRA catalog. We obtain physically meaningful upper limits on scalar densities around most compact binaries. For GW190728 and GW190814, vacuum lies outside the $95\%$ credible region. When including superradiance priors, GW190728 shows tentative evidence for a scalar environment with a Bayes factor of $\ln \mathrm{B}^{\rm env}_{\rm vac} \approx 3.5$, consistent with a light scalar of mass $\sim10^{-12}\,\mathrm{eV}$.

arXiv.org
LIGOMay 14

"On the application of astrophysical signals to gravitational-wave detector calibration" — an artistic interpretation of our latest science with #GW240925 and #GW250207 by @ASleepyWanderer

For the first time, we have used the signals from binary black holes to check the precise calibration of our detectors

#Astrodon #ArtSci #GravitationalWaves