#galaxy-formation — Public Fediverse posts

Weekly Update from the Open Journal of Astrophysics – 18/04/2026

It is Saturday morning, and therefore time for yet another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 82 and the total so far published by OJAp up to 530.

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 “Beyond Spherical geometry: Unraveling complex features of objects orbiting around stars from its transit light curve using deep learning” by Ushasi Bhowmick & Shivam Kumaran (Indian Space Research Institute, Ahmedabad, India). This study uses deep neural networks to predict the shape of objects orbiting stars based on their transit light curves, demonstrating the potential to extract geometric information from these systems. It was published on Monday 13th April in the folder Earth and Planetary Astrophysics and the overlay can be seen here:

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

https://fediscience.org/@OJ_Astro/116395992732332356

The second paper for this week, also published on Monday 13th April Apil in the folder but in the folder Astrophysics of Galaxies, is “statmorph-lsst: Quantifying and correcting morphological biases in galaxy surveys” by Elizaveta Sazonova (U. Waterloo, Canada) and an international cast of 18 others. This paper presents an investigation of potential biases in quantitative morphology metrics used in galaxy evolution studies, proposing two new measurements to resolve biases, and provides a related Python package (statmorph-lsst), which can be found here on github.

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/116396069424189312

Next one up, the third paper of the week, one of four published on Friday 17th April, is “Disentangling the galactic and intergalactic components in 313 observed Lyman-alpha line profiles between redshift 0 and 5” by Siddhartha Gurung-López (Universitat de València, Spain) and 7 others based in Spain and Germany. Published in the folder Astrophysics of Galaxies, this paper uses the zELDA package to analyze Lyman-alpha photons from star-forming galaxies, revealing IGM effects dominate Lyman-alpha observability at high redshifts, while galactic outflows become more important at lower z.

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/116418831864134501

The fourth paper this week, also published on Friday 17th April is “Using Symbolic Regression to Emulate the Radial Fourier Transform of the Sérsic Profile for Fast, Accurate and Differentiable Galaxy Profile Fitting” by Tim B. Miller (Northwestern University, USA) and Imad Pasha (Yale University, USA). This one is published in the folder Instrumentation and Methods for Astrophysics: it develops an emulator for galaxy profile fitting in Fourier space, improving speed by 2.5 times with minimal accuracy loss, aiding in managing increasing data flow.

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/116418855010158656

The fifth paper for this week is “The THESAN project: Lyman-alpha emitters as probes of ionized bubble sizes” by Meredith Neyer (MIT, USA) and 6 others based in the USA, Colombia, Canada, Japan and UK. The study uses THESAN simulations to explore how Lyman-alpha emitters (LAEs) trace ionized bubble sizes during the Epoch of Reionization, providing a framework for interpreting LAE surveys. This was published on Friday 17th April in the folder Astrophysics of Galaxies.

The overlay for this one 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/116418887225003954

The sixth and final paper for this week is “Closed-Form Statistical Relations Between Projected Separation, Semimajor Axis, Companion Mass, and Host Acceleration” by Timothy D Brandt (Space Telescope Science Institute, USA). This was published on Friday 17th April in the folder Solar and Stellar Astrophysics. In this paper the author derives statistical relationships between radial velocity, a companion’s mass, and projected separation, useful for calculations requiring derivatives. The results are verified with empirical comparisons to existing literature.

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/116418938017199814

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

P.S. Just a reminder, for those of you into LinkedIn, that we now have a page there.

The #COLIBRE project - calibrating subgrid feedback in cosmological simulations that include a cold gas phase / Cosmological hydrodynamical #simulations of #GalaxyFormation and evolution: https://academic.oup.com/mnras/article/548/1/stag300/8650960 / https://academic.oup.com/mnras/article/548/1/stag375/8650959 -> New simulations reveal the cold, dusty reality of galaxy formation: https://www.astronomie.nl/nieuws/en/new-simulations-reveal-the-cold-dusty-reality-of-galaxy-formation-4807

Weekly Update from the Open Journal of Astrophysics – 11/04/2026

With permission, I have time for yet another Saturday morning 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 76 and the total so far published by OJAp up to 524.

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 “Lagrangian versus Eulerian Methods for Toroidally-Magnetized Isothermal Disks” by Yashvardhan Tomar and Philip F. Hopkins (California Institute of Technology, USA). This study re-evaluates previous research on toroidally-magnetized disks, using two Lagrangian methods. The results suggest that sustained midplane toroidal fields in recent simulations are not a numerical artefact. It was published on Tuesday April 7th 2026 in the folder High-Energy Astrophysical Phenomena.

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/116362395042011770

The second paper for this week, published on Wednesday 8th Apil in the folder Instrumentation and Methods for Astrophysics, is “Teaching Astronomy with Large Language Models” by Yuan-Sen Ting and Teaghan O’Briain (Ohio State University, USA). The paper introduces AstroTutor, an AI-enhanced astronomy tutoring system, to improve undergraduate astronomy education and AI literacy. It found that structured AI integration can enhance learning and critical evaluation skills. The primary classification on arXiv for this paper is physics.ed-ph but it is cross-listed on astro-ph which qualifies it for consideration.

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/116368195945602700

Next one up, the third paper of the week, also published on Wednesday 8th April, is “Statistical Predictions of the Accreted Stellar Halos around Milky Way-Like Galaxies” by J. Sebastian Monzon & Frank C. van den Bosch (Yale University, USA) and Martin P. Rey (University of Bath, UK). This one was published in the section Astrophysics of Galaxies; it describes new model to track formation of stellar halos in Milky Way-like galaxies, revealing their sensitivity to the fate of the largest satellite and whether accretion is early or late.

The overlay for this one is here:

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

The fourth paper this week, published on Thursday 9th April is “A Tale of Tails: Star Formation and Stripping in Jellyfish Galaxies in the Strong Lensing Cluster MACS J0138.0-2155” by Catherine C. Gibson, Jackson H. O’Donnell and Tesla E. Jeltema (UC Santa Cruz, USA). This investigates the effects of ram-pressure stripping on four galaxies, focusing on their stellar and gas kinematics, star formation rates, and galactic structure and is published in the folder marked Astrophysics of Galaxies.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116374103962641944

The fifth and final paper for this week is “Investigating ionising sources and the complex interstellar medium of GHZ2 at z=12.3” by M. Castellano (INAF Osservatorio Astronomico di Roma, Italy) and 29 others based all around the world. This was also published on Thursday 9th April in the folder Astrophysics of Galaxies. The paper uses deep observations of galaxy GHZ2 to explore the sources of ionising radiation and interstellar medium properties at cosmic dawn. Findings suggest a stratified environment and a hard ionising radiation component.

The overlay for this one is here:

The officially-accepted version of this one can be found on arXiv here and the Mastodon announcement is here

https://fediscience.org/@OJ_Astro/116374246020924265

That concludes this week’s update. I’ll do another one at the end of next week, when the Easter vacations will be over.

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

It may be the Easter weekend, but it’s still time for a Saturday morning update of activity at the Open Journal of Astrophysics. Since the last update we have published a further four papers, bringing the number in Volume 9 (2026) to 71 and the total so far published by OJAp up to 519. This update coimpletes the first quarter of 2026, which suggests that if we continue to publish at the same rate we’ll reach about 280 for the year.

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 “Testing halo models for constraining astrophysical feedback with multi-probe modeling: I. 3D Power spectra and mass fractions” by Pranjal R. S. (U. Arizona, USA), Shivam Pandey Johns Hopkins U., USA), Dhayaa Anbajagane (U. Chicago, USA), Elisabeth Krause (U. Arizona) and Klaus Dolag (Max Planck Institute for Astrophysics, Germany). This paper was published on Tuesday March 31st in the folder Cosmology and Nongalactic Astrophysics.

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/116322295318460212

The second paper for this week, also published on Tuesday March 31st in the folder Cosmology and Nongalactic Astrophysics, is “Validation of the DESI-DR1 3×2-pt analysis: scale cut and shear ratio tests” by Ni Putu Audita Placida Emas (Swinburne University of Technology, Australia) and an international cast of 56 others. This study validates the combined analysis of galaxy clustering and weak gravitational lensing data from various surveys, ensuring accurate tests of the standard cosmological model using future Stage-IV surveys

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/116322348900996677

Next one up, the third paper of the week, also published on Tuesday March 31st in the folder Cosmology and Nongalactic Astrophysics, is “Differentiable Stochastic Halo Occupation Distribution with Galaxy Intrinsic Alignments” by Sneh Pandya and Jonathan Blazek (both of Northeastern University, USA). This is a paper introducing diffHOD-IA, a differentiable model for galaxy population analysis that incorporates intrinsic alignments and halo occupation distribution. It’s validated against existing models and can be used in next-generation weak-lensing analyses.

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/116322403314492269

The fourth and final paper this week, published on Wednesday April 1st (but not a joke), is “The Growth of Dust in Galaxies in the First Billion Years with Applications to Blue Monsters” by Desika Narayanan (U. Florida, USA) and 11 others based in the USA and Europe. This one is in the folder Astrophysics of Galaxies; it presents a simulation-based study of dust accumulation in early galaxies via supernovae production and rapid growth on tiny dust grains, with local density and grain size being important factors.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116328145696781139

And that concludes the update for this week. I’ll do another next week, but I’m expecting a fairly low number of papers owing to the Easter vacation.

#Reproducibility in numerical #GalaxyFormation with #Maneage [1] - ongoing lab course [2]. A 5-yr old reproducible paper (Roukema+Peper2021) [3] was not as trivially reproducible as hoped, but now seems OK in 2026 with commit 024d1f21 [4] maneage #AstroRelatedPython updates [5].

@cosmology @makhlaghi

[1] https://maneage.org

[2] https://cosmo.torun.pl/Cosmo/GalaxyFormationCourse

[3] https://ui.adsabs.harvard.edu/abs/2021MNRAS.505.1223P = https://arxiv.org/abs/2010.03742 = https://zenodo.org/records/4699702

[4] https://codeberg.org/boud/elaphrocentre/commit/17c7d9033abda74fe5e8bf029119565b8a0be2ce

[5] https://savannah.nongnu.org/task/index.php?16740

Weekly Update from the Open Journal of Astrophysics – 07/02/2026

It’s Saturday once more so time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further six papers, bringing the number in Volume 9 (2026) to 24 and the total so far published by OJAp up to 472.

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 announcement also show the DOI for each paper.

The first paper to report this week is “The Impact of Star Formation and Feedback Recipes on the Stellar Mass and Interstellar Medium of High-Redshift Galaxies” by Harley Katz (U. Chicago, USA), Martin P. Rey (U. Oxford, UK), Corentin Cadiou (Lund U., Sweden) Taysun Kimm (Yonsei U., Korea) and Oscar Agertz (Lund). This paper was published on Monday 2nd February 2026 in the folder Astrophysics of Galaxies. It introduces MEGATRON, a new model for galaxy formation simulations, highlighting that feedback energy controls star formation at high redshift and highlighting the importance of the interstellar medium.

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/116000695648050758

The second paper is “Photometric Redshifts in JWST Deep Fields: A Pixel-Based Alternative with DeepDISC” by Grant Merz (U. Illinois at Urbana-Champaign) and 6 others, all based in the USA. This paper was published on Monday February 2nd 2026 in the folder Instrumentation and Methods for Astrophysics. This paper explores the effectiveness of the DeepDISC machine learning algorithm in estimating photometric redshifts from near-infrared data, demonstrating its potential for larger image volumes and spectroscopic samples

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/116000777572439111

Next, published on Wednesday 4th February in the folder Astrophysics of Galaxies, is “Inferring Interstellar Medium Density, Temperature, and Metallicity from Turbulent H II Regions” by Larrance Xing (U. Chicago, USA), Nicholas Choustikov (U. Oxford, UK), Harley Katz (U. Chicago) and Alex J. Cameron (DAWN, Denmark). This paper argues that supersonic turbulenc affects the interpretation of H II region properties, potentially impacting inferred metallicity, ionization, and excitation from in nebular emission lines, motivating more extensive modelling.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116011384659092223

The fourth paper this week, also published on Wednesday 4th February, but in the folder Solar and Stellar Astrophysics, is “A Systematic Search for Big Dippers in ASAS-SN” by B. JoHantgen, D. M. Rowan, R. Forés-Toribio, C. S. Kochanek, & K. Z. Stanek (Ohio State University, USA), B. J. Shappee (U. Hawaii, USA), Subo Dong (Peking University), J. L. Prieto Universidad Diego Portales, Chile) and Todd A. Thompson (Ohio State). This study identifies 4 new dipper stars and 15 long-period eclipsing binary candidates using ASAS-SN light curves and multi-wavelength data, categorizing them based on their characteristics.

Here is the overlay:

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

https://fediscience.org/@OJ_Astro/116011460612040834

Fifth, and next to last this week we have “Unveiling the drivers of the Baryon Cycles with Interpretable Multi-step Machine Learning and Simulations” by Mst Shamima Khanom, Benjamin W. Keller and Javier Ignacio Saavedra Moreno (U. Memphis, USA). This paper was published on Thursday 5th February 2026 in the folder Astrophysics of Galaxies. This study uses machine learning methods to understand how galaxies lose or retain baryons, highlighting the relationship between baryon fraction and various galactic measurements.

The overlay is here:

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

https://fediscience.org/@OJ_Astro/116016883984380622

Finally for this week we have “The Bispectrum of Intrinsic Alignments: II. Precision Comparison Against Dark Matter Simulations” by Thomas Bakx (Utrecht U., Netherlands), Toshiki Kurita (MPA Garching, Germany), Alexander Eggemeier (U. Bonn, Germany), Nora Elisa Chisari (Utrecht) and Zvonimir Vlah (Ruđer Bošković Institute, Croatia). This paper was accepted in December, but publication got delayed by the Christmas effect so was published on February 6th 2026, in the folder Cosmology and Nongalactic Astrophysics. This study uses N-body simulations to accurately measure three-dimensional bispectra of halo intrinsic alignments and dark matter overdensities, providing a method to determine higher order shape bias parameters.

The overlay is here:

You can find the published version of the article here, and the Mastodon announcement is here:

https://fediscience.org/@OJ_Astro/116022562915557971

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

A Cosmic Miracle?

A while ago (last May, in fact) I posted an article about a galaxy with an apparent spectroscopic redshift of 14.44. The paper to which that post related had been submitted to the Open Journal of Astrophysics and I haven’t mentioned that paper again until now as the paper was then, so to speak, sub judice. Well, as of today, the paper is now published and will feature in tomorrow’s traditional Saturday roundup of publications at the journal.

This paper was in fact accepted for publication before Christmas, but it took until this morning for the final accepted article to reach the arXiv. Rather awkwardly, the Space Telescope Science Institute issued a press release about this paper on 28th January 2026 stating that the paper was published in the Open Journal of Astrophysics, when that statement was not accurate. As Editor-in Chief of the Open Journal of Astrophysics, I was subsequently contacted by a number of journalists asking where they could find the paper on the OJAp platform. Since it hadn’t been published then I had to say they couldn’t, so a number of pieces (including, for example, this one in Scientific American) have appeared based on the STSCi press release without links to the final version of the paper. It would have been far better, in my opinion, to have delayed the press release until the paper was actually published.

Anyway, thanks to me getting up at 6am today, it’s now published so there’s no real harm done.

The fediscience announcement is here:

https://fediscience.org/@OJ_Astro/115982837486159819

For reference, here is the key plot showing the spectrum from which the galaxy’s redshift is determined. It is rather noisy, but the Lyman break seems convincing and there are some emission lines that offer corroborative evidence:

#arXiv250511263v2 #Cosmology #galaxyFormation #highRedshiftGalaxy #LymanBreak #z1444

Weekly Update from the Open Journal of Astrophysics – 04/10/2025

It’s Saturday again, so it’s time for a summary of the week’s new papers at the Open Journal of Astrophysics. Since the last update we have published five more papers, which brings the number in Volume 8 (2025) up to 146, and the total so far published by OJAp up to 381. At this rate Volume 8 will contain around 190 by the end of 2025.

Anyway, here are this week’s papers, starting with three published on Monday 29th September 2025.

The first paper is “Cosmic Multipoles in Galaxy Surveys II: Comparing Different Methods in Assessing the Cosmic Dipole” by Vasudev Mittal, Oliver T. Oayda and Geraint F. Lewis (U. Sydney, Australia). This is in the folder Cosmology and Nongalactic Astrophysics. It presents a comparison of methods for determining the number count dipole from cosmological surveys with a discussion of the implications for the known discordance with the CMB diple.

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, also published on Monday 29th September, is “SDSS-C4 3028: the Nearest Blue Galaxy Cluster Devoid of an Intracluster Medium” by Shweta Jain (University of Kentucky, USA) and 11 others based in the USA, Australia and Korea. This describes a galaxy cluster with an unusually high fraction (about 63%) of star-forming galaxies which may be a result of ram pressure stripping; the article is in the folder Astrophysics of Galaxies.

The corresponding overlay is here:

You can find the officially accepted version on arXiv here.

The third one this week, published on also published on Monday 29th September but in the folder Earth and Planetary Astrophysics, is “Comparing the Architectures of Multiplanet Systems from Kepler, K2, and TESS Data” by Robert L Royer and Jason H. Steffen (University of Nevada, USA).  This paper explores the trends seen in exoplanet survey data, including Kepler, TESS, and K2 including many planetary systems with multiple planets.

The overlay is here:

You can find the officially-accepted version on arXiv here.

The next one up is “Seeding Cores: A Pathway for Nuclear Star Clusters from Bound Star Clusters in the First Billion Years” by Fred Angelo Batan Garcia (Columbia University, USA), Massimo Ricotti (University of Maryland, USA) and Kazuyuki Sugimura (Hokkaido University, Japan). This paper was published on Thursday 2nd October in the folder Astrophysics of Galaxies. This is about modelling the formation of Nuclear Star Clusters using cosmological radiation-hydrodynamic simulations, with discussion of the implications for seeding supermassive black holes and the little red dots seen by JWST.

The corresponding overlay is here:

You can find the officially accepted version of this one on arXiv here.

The fifth and last one for this week, published on Friday 3rd October 2025, is “Efficient semi-analytic modelling of Pop III star formation from Cosmic Dawn to Reionization” by Sahil Hegde and Steven R. Furlanetto (University of Californi Los Angeles, USA).  This is also in the folder marked Astrophysics of Galaxies. It uses a self-consistent analytic model to trace the formation of the first stars from their birth through the first billion years of the universe’s history. complementing semi-analytic and computational methods.

You can find the officially-accepted version of this paper on arxiv here.

That concludes the report for this week. I’ll post another update next Saturday.

#arXiv250308779v2 #arXiv250620654v3 #arXiv250719581v2 #arXiv250920651v1 #arXiv250922523v1 #AstrophysicsOfGalaxies #cosmicDipoles #CosmologyAndNonGalacticAstrophysics #DiamondOpenAccess #EarthAndPlanetaryAstrophysics #GalaxyCluster #galaxyFormation #galaxySurveys #JWST #Kepler #LittleRedDots #MultiplanetSystems #nuclearStarClusters #OpenAccessPublishing #OpenJournalOfAstrophysics #PopulationIIIStars #ramPressureStripping #SDSSC42028 #semiAnalyticGalaxyFormation #TheOpenJournalOfAstrophysics

Galaxies and Black Holes in the First Billion Years

Trying to catch up on recent developments in galaxy formation? I can heartily recommend an excellent review article on the subject by Richard Ellis which you can find on the arXiv here. The abstract reads:

 I present written notes from three lectures given at the 54th Saas-Fee Advanced Course of the Swiss Society of Astrophysics and Astronomy in January 2025 entitled “Galaxies and Black Holes in the First Billion Years as seen by the JWST”. I focused my lectures on progress in studies of cosmic reionisation, the properties of galaxies in the reionisation era, topics related to the redshift frontier and the search for Population III stars. The lectures were given to graduate students in astrophysics and cover both pedagogical material as well as observational results from the first two and half years of JWST science operations. The pace of discovery with JWST is, of course, rapid and so my lectures discuss long-term goals, analysis methods and their assumptions and limitations in the hope that the underlying material will retain value in the near future. In this written version, the visual material is that presented at Saas-Fee in January 2025 but I have provided updates on progress from the literature up to August 2025. The material is aimed at early career researchers and should not be considered as a scholarly review of the entire JWST literature on high redshift galaxies.

It’s quite a long article (65 pages) but nicely written and well worth reading, as it is full of information about recent advances as well as historical insights. Talking of which, there’s a picture on page 41 taken at a meeting in Durham in 1988 called The Epoch of Galaxy Formation that I attended while I was still a graduate student:

Richard Ellis himself is in the front row, left of centre with light-coloured trousers, checked shirt and hands in pockets. I’m in the picture too, but I’ll leave it up to you to find me!

A poll was held among the delegates at that meeting about various questions to do with galaxy formation. The majority opinions revealed by these votes nearly all turned out to be utterly wrong! That’s progress, I guess…

#arXiv250816948 #blackHoles #Cosmology #galaxyFormation #JWST #RichardEllis

Oldest Galaxy That Formed 280 million Years After The Big Bang Has Been Identified And Proves Yet Again How Unimaginably Large The Universe Really Is » TwistedSifter

COSMOS-Web From our tiny part of space, it can be hard to image exactly how much is out…
#NewsBeep #News #Science #AU #Australia #BigBang #cosmos-web #distantgalaxy #galaxy #galaxyformation #Jameswebbspacetelescope #JWST #MilkyWay #mom-z14 #singletopic #Space #top #Universe
https://www.newsbeep.com/au/89919/

A galaxy at redshift z=14.44?

This morning’s arXiv mailing presented me with a distraction from examination marking in the form of a paper by Naidu et al. with this abstract:

This paper has been submitted to the Open Journal of Astrophysics. I usually feel a bit conflicted in situations when a paper has been submitted for editorial review. I am posting it here for two reasons: one is that I am not the Editor responsible for this paper; the other is that the arXiv submission specifically says “Submitted to the Open Journal of Astrophysics. Comments greatly appreciated and warmly welcomed!”. In order to generate flagging it here to encourage people to comment, either through the box below or by contacting the authors.

For reference, here is the key plot showing the spectrum from which the redshift is determined. It is rather noisy, but the Lyman break seems reasonably convincing and there are some emission lines that appear to offer corroborative evidence:

You might want to read this article (abother OJAp paper) which contains this plot showing how galaxies at redshift z>10 challenge the standard model:

Please read the paper and comment if you wish!

#arXiv250511263 #Cosmology #galaxyFormation #highRedshiftGalaxy #LymanBreak #z1444

R.I.P. Jerry Ostriker (1937-2025)

Once again I find myself using this blog to pass on sad news. This time it is of the death of renowned astrophysicist Jerry Ostriker (pictured left in 2012), who passed away on Monday 6th April 2025 just a week before his 88th birthday.

Jeremiah Paul Ostriker (to give his full name) was an extremely energetic, versatile and influential theorist who worked on a wide range of problems in diverse areas of astrophysics and produced a number of classic papers. Close to my own specialism I would quote two in particular: one written with Jim Peebles in 1973 about the stability of galactic disks; and the other with Martin Rees in 1977 about the role of gas cooling and fragmentation in determining the size of galaxies and clusters. He also did much to establish the use of hydrodynamic simulations in cosmology and was an early adopter of the current standard cosmological model, including a cosmological constant. He worked on many other things too, including pulsars and galactic nuclei.

I only met Jerry Ostriker a few times, mainly at conferences – where he was never shy to contribute to discussions after talks – but also once back in the 1990s when I was a visitor Princeton (where he was Professor). I didn’t have much time to talk to him then as he always seemed to be on the go, so I never really got to know him personally. After spending most of his career in Princeton, including a spell as Provost, in 2001 Ostriker moved to Cambridge for a short stint as Plumian Professor, before returning to Princeton.

There is a very nice obituary of Jerry Ostriker by Dennis Overbye in the New York Times.

Rest in peace, Jerry Ostriker

#Astrophysics #Cosmology #galaxyFormation #JeremiahPOstriker #JerryOstriker #Princeton

#LCDM #GalaxyFormation #EarlyGalaxies #Illustris
"Old galaxies in the early universe"

<<it isn’t a resounding success if we have to scrape the bottom of the simulated barrel after cherry-picking which barrel.>>

#MOND #MassiveGalaxies

🔗https://tritonstation.com/2025/01/14/old-galaxies-in-the-early-universe/

Very readable blog about cosmology with some surprisingly easy to understand "back of the envelope" calculations about the boundary conditions under which galaxies may form.

https://tritonstation.com/2024/12/20/on-the-timescale-for-galaxy-formation/

#tritonstation #cosmology #jwst #MOND #darkmatter #galaxyformation

How does LCDM fit to JWST data as compared to MOND's predictive power?

https://tritonstation.com/2024/11/12/massive-galaxies-at-high-redshift-we-told-you-so/

#lcdm #mond #galaxyformation #astrophysics

Paradox of Metal-rich Stars in Early Universe  
Study of image taken by the JWST has led to discovery of a galaxy in the early universe about a billion years after the big bang whose light...........
#earlyuniverse #galaxy #galaxyformation #GSNDG9422 #JADESGSz140 #JamesWebbSpaceTelescope #JWST #metalrichstars #PopIIIStars #Universe
Umesh Prasad

https://www.scientificeuropean.co.uk/sciences/space/paradox-of-metal-rich-stars-in-early-universe/

Early Universe: The Most Distant Galaxy “JADES-GS-z14-0" Challenges Galaxy Formation Models  
Spectral analysis of luminous galaxy JADES-GS-z14-0 based on observations made in January 2024 revealed a redshift of 14.32...........
#earlyuniverse #galaxy #galaxyformation #JADES #JADESGSz140 #jameswebb #JamesWebbSpaceTelescope #JWST #Universe
Umesh Prasa

https://www.scientificeuropean.co.uk/sciences/space/early-universe-the-most-distant-galaxy-jades-gs-z14-0-challenges-galaxy-formation-models/

The James Webb Space Telescope has confirmed that the earliest known galaxy in the universe contains far more stars than previously thought possible. This revelation challenges existing models of galaxy formation and evolution, suggesting that star formation in the early universe was more prolific than anticipated.

#Astronomy #JamesWebbTelescope #GalaxyFormation #SpaceDiscovery #Cosmology

https://www.livescience.com/space/astronomy/james-webb-telescope-confirms-the-earliest-galaxy-in-the-universe-is-bursting-with-way-more-stars-than-we-thought-possible?utm_source=flipboard&utm_content=HariTulsidas%2Fmagazine%2FMind+and+Matter

Early Universe: The Most Distant Galaxy “JADES-GS-z14-0" Challenges Galaxy Formation Models  
Spectral analysis of luminous galaxy JADES-GS-z14-0 based on observations made in January 2024 revealed a redshift of 14.32...........
#earlyuniverse #galaxy #galaxyformation #JADES #JADESGSz140 #jameswebb #JamesWebbSpaceTelescope #JWST #Universe
Umesh Prasa

https://www.scientificeuropean.co.uk/sciences/space/early-universe-the-most-distant-galaxy-jades-gs-z14-0-challenges-galaxy-formation-models/

Webb confirms: Big, bright galaxies formed shortly after the Big Bang - Enlarge / Some of the galaxies in the JADES images. (credit: NASA, ESA,... - https://arstechnica.com/?p=2040341 #galaxyformation #webbtelescope #astronomy #cosmology #galaxies #science

JADES Transient Survey (NIRCam Image) ✨

#Cosmology #DistantGalaxies #FirstGalaxies #Galaxies #GalaxyEvolution #GalaxyFormation

⏩ 2 new pictures from Webb (NASA) https://commons.wikimedia.org/wiki/Special:ListFiles?limit=4&user=OptimusPrimeBot&ilshowall=1&offset=20240611103226

Galaxy Forming in the Early Universe (Artist’s Concept) ✨

#Cosmology #DistantGalaxies #FirstGalaxies #Galaxies #GalaxyEvolution #GalaxyFormation

▶️ 1 new picture from Webb (NASA) https://commons.wikimedia.org/wiki/File:Galaxy_Forming_in_the_Early_Universe_%28Artist%E2%80%99s_Concept%29_%282024-114%29.tiff

Portion of Cosmic Evolution Early Release Science (CEERS) Survey (NIRCam Compass Image) ✨

#DistantGalaxies #Galaxies #GalaxyEvolution #GalaxyFormation

⏩ 4 new pictures from Webb (NASA) https://commons.wikimedia.org/wiki/Special:ListFiles?limit=7&user=OptimusPrimeBot&ilshowall=1&offset=20240118103343

#GalaxyFormation
"James Webb Space Telescope and ALMA capture the core of the most distant galaxy protocluster"
🔗https://phys.org/news/2023-09-james-webb-space-telescope-alma.html

"cosmological simulations... predict that the member galaxies are on the verge of merging in... several tens of Myr to become a large galaxy with M* ∼ 6E9M⊙."
Open Access article
"Reionization and the ISM/Stellar Origins with JWST and ALMA (RIOJA): Core of Highest-redshift Galaxy Overdensity at z = 7.88 Confirmed by NIRSpec/JWST"
🔗https://iopscience.iop.org/article/10.3847/2041-8213/acf57c

🤗🥳We are very happy to announce that Frank Eisenhauer starts as a new Director at #MPE! With #SINFONI, #GRAVITY & #GRAVITY+, Eisenhauer is building first-class instruments which led to outstanding results in #BlackHole, #GalacticCenter, #Exoplanet & #GalaxyFormation science!
➡https://www.mpe.mpg.de/7948075/news20230515

#PaulSteinhardt - How Does #DarkEnergy Drive the #Universe?

https://www.youtube.com/watch?v=VcACmz53LpU&ab_channel=CloserToTruth

#Physics #Science #Cosmology #PhilosophyOfScience #PhilosophyOfCosmology #BigBang #MassEnergy #CosmologicalConstant #GR #GeneralRelativity #GalaxyFormation #CloserToTruth #RobertKuhn

Webb confirms we’re looking at some of the Universe’s earliest galaxies - Enlarge / Galaxies that appear to be similar in age to the ones describ... - https://arstechnica.com/?p=1929051 #jameswebbspacetelescope #galaxyformation #astronomy #cosmology #science

I had missed this article, the title of which made me laugh out loud.
https://www.sciencealert.com/astronomers-detect-6-massive-galaxies-so-old-they-cant-be-explained-by-science
Not only can these observations be explained by science, they were predicted by it in advance.
https://tritonstation.com/2023/03/10/cant-be-explained-by-science/
People just still don't seem to know about it (or are living in denial).
#astronomy #cosmology #galaxyformation #JWST #research

One week later, astronomers find a galaxy even deeper back in time - Enlarge / The James Webb Space Telescope continues to deliver on its pr... - https://arstechnica.com/?p=1869571 #galaxyformation #webbtelescope #astronomy #cosmology #science