Archive for quasars

Weekly Update from the Open Journal of Astrophysics – 30/08/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , on August 30, 2025 by telescoper

Once again 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 three new papers, which brings the number in Volume 8 (2025) up to 125, and the total so far published by OJAp up to 360.

The first paper to report this week is “Large-scale surveys of the quasar proximity effect” by Rupert Croft, Patrick Shaw & Ann-Marsha Alexis (Carnegie Mellon University; CMU), Nianyi Chen (Princeton), Yihao Zhou & Tiziana Di Matteo (CMU), Simeon Bird (UC Riverside), Patrick Lachance (CMU), and Yueying Ni (Harvard). This paper was published on Monday 25th August in the folder Cosmology and NonGalactic Astrophysics. It presents a CDM-based halo model of the quasar proximity effect, tested on quasar Lyman-alpha spectra from the ASTRID cosmological simulation, including self-consistent formation of quasar black holes and the intergalactic medium.

The overlay is here:

 

You can make this larger by clicking on it, as you can with all the overlays below. The officially accepted version of this paper can be found on the arXiv here.

The second paper this week, also published on Monday 25th August, but in the folder Astrophysics of Galaxies, is “Redshift evolution of Lyman continuum escape fraction after JWST” by Andrea Ferrara (Pisa), M. Giavalisco (UMass Amherst), L. Pentericci (Rome), E. Vanzella (Bologna), A. Calabrò (Rome) and M. Llerena (Rome). This paper is about the Attenuation-Free Model (AFM) for galaxies, in which radiation-driven outflows develop once the galaxy specific star formation rate exceeds a certain level, which is tested on data with positive results. The overlay is here:

You can find the officially accepted version on arXiv here.

The third and final paper this week is “Primordial black holes in cosmological simulations: growth prospects for supermassive black holes” by Lewis R Prole, John A Regan, Daxal Mehta & Peter Coles (National University of Ireland, Maynooth) and Pratika Dayal (Groningen, NL). This one was published in Astrophysics of Galaxies folder on Thursday 28th August 2025. You can read more about this paper here: basically it studies the growth of primordial black holes in the early Universe using numerical simulations, with implications for the subsequent formation of massive black holes.

The overlay is here:

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

And that’s all the papers for this week. It’s still a bit slow as we emerge from the summer vacations, but I expect things will start to pick up from now on.

Weekly Update from the Open Journal of Astrophysics – 16/08/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , on August 16, 2025 by telescoper

It’s time once again for the usual update of papers published at the Open Journal of Astrophysics which I do every Saturday. Since the last update we have published two new papers, which brings the number in Volume 8 (2025) up to 116, and the total so far published by OJAp up to 351. The summer lull we always expected is now upon us, so this will be a shorter post than we have had of late.

The first paper to report this week is “The reflex instability: exponential growth of a large-scale mode in astrophysical discs” by Aurélien Crida (Université Côte d’Azur, France), Clément Baruteau (Université de Toulouse, France), Jean-François Gonzalez (Universite Claude Bernard Lyon 1, France), Frédéric Masset (Universidad Nacional Autonoma de México) and Paul Segretain, Philippine Griveaud, Héloïse Méheut & Elena Lega (Université Côte d’Azur).  This paper was published on Tuesday August 12th 2025 in the folder marked “Earth and Planetary Astrophysics“. It discusses a exponentially-growing instability in gas discs around stars caused by the motion of the central star in response to the disc.

The overlay – which you can make larger by clicking on it – is here:

You can find the officially accepted version on arXiv here.

The other paper this week, published in the folder Cosmology and Nongalactic Astrophysics, is “The galaxy-IGM connection in THESAN: the physics connecting the IGM Lyman-alpha opacity and galaxy density in the reionization epoch” by Enrico Garaldi (University of Tokyo, Japan), Verena Bellscheidt (Technical University of Munich, Germany), Aaron Smith (York University, Canada) and Rahul Kannan (University of Texas at Dallas, USA).  It presents a study of the relation between the Lyman-alpha effective optical depth of quasar sightlines and the distribution of galaxiesas as a probe of ionized regions around sources of photons. It was published on Wednesday August 13th 2025.

The overlay is here:

 

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

That concludes the papers for this week. I’ll do another update next weekend, though I expect things will remain relatively quiet until September.

Weekly Update from the Open Journal of Astrophysics – 09/08/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , on August 9, 2025 by telescoper

It’s Saturday morning so, once again, it’s time for an 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 114, and the total so far published by OJAp up to 349.

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 “Caught in the Act of Quenching? – A Population of Post-Starburst Ultra-Diffuse Galaxies” by Loraine Sandoval Ascencio & M. C. Cooper (UC Irvine), Dennis Zaritsky, Richard Donnerstein & Donghyeon J. Khim (U. Arizona) and Devontae C. Baxter (UC San Diego). This paper was puvblished on Monday 4th August and is in the folder marked Astrophysics of Galaxies. It discusses a sample of Ultra-Diffuse Galaxies (UDGs) found to be post-starburst galaxies through spectroscopic analysis analysis of candidates selected from the Systematically Measuring Ultra-Diffuse Galaxies (SMUDGes) program.

The overlay is here:

 

 

The officially-accepted version can be found on arXiv here.

Next one up, published on Tuesday 5th August, in the folder Cosmology and Nongalactic Astrophysics, is “Damping Wing-Like Features in the Spectra of High Redshift Quasars: a Challenge for Fully-Coupled Simulations” by Nick Gnedin & Hanjue Zhu (University of Chicago, USA).  This paper presents a discussion of the difficulties that cosmological radiation transfer codes have in accounting for the existence of “neutral islands” in the universe at relatively low redshifts.

The overlay is here:

 

 

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

The third paper of the week is “Spectroscopic Analysis of Pictor II: a very low metallicity ultra-faint dwarf galaxy bound to the Large Magellanic Cloud” by Andrew Pace (U. Virginia, USA) and 32 others based in the USA, UK, Canada, Chile and Spain. This one was also published on Tuesday 5th August but in the folder Astrophysics of Galaxies. It describes Magellan/IMACS and Magellan/MIKE spectroscopy of the ultra-faint dwarf (UFD) galaxy Pictor II, which is located only 12 kpc from the Large Magellanic Cloud (LMC).

The overlay is here:

 

The final version is on arXiv here.

The fourth, and final, paper of the week, also published on Thursday 7th August, is “ASASSN-24fw: An 8-month long, 4.1 mag, optically achromatic and polarized dimming event” by Raquel Forés-Toribio (Ohio State University) and 22 others based in the USA, Austria, Chile and Australia. It is published in the folder Solar and Stellar Astrophysics, and it presents an observational study of an unusual dimming event likely to have been caused by eclipsing of a binary system by a dusty disk.

Here is the overlay:

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

And that’s all the papers for this week. I’ll do another update next Saturday.

P.S. For those of you who missed the post I did earlier in the week, I have been looking at the accounts for the Open Journal of Astrophysics and can confirm that the cost to us per paper is less than $30 and will reduce with scale. We expect to publish around 180 papers in 2025 for which the total cost incurred by OJAp will be around $5000. Obviously if we increase by a factor, say, ten then that amount would become significant so we are taking steps to secure additional funding in the event that happens.

Weekly Update from the Open Journal of Astrophysics – 02/08/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , on August 2, 2025 by telescoper

It’s Saturday morning again, and it’s the start of a new month, so it’s time for an update of papers published at the Open Journal of Astrophysics. Since the last update we have published five new papers, which brings the number in Volume 8 (2025) up to 110, and the total so far published by OJAp up to 345. I expect we’ll the total number we published last year (120) sometime this month. I predict that by the end of this year we will have published around 180 papers in Volume 8 and around 400 altogether.

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 matter with(in) CPL” by Leonardo Giani (U. Queensland, Australia), Rodrigo Von Marttens (Universidade Federal da Bahia, Brazil) and Oliver Fabio Piattella (Universita degli Studi dell’Insubria, Italy). This was published on Monday 29th July 2025 in the folder Cosmology and Nongalactic Astrophysics. This article presents a new parameterization of the standard model and its implications for the interpretation of cosmological observations.

The overlay is here:

 

The officially-accepted version can be found on arXiv here.

The second paper of the week, published on Tuesday 30th July in the folder Instrumentation and Methods for Astrophysics, is “An automated method for finding the most distant quasars” by Lena Lenz, Daniel Mortlock, Boris Leistedt & Rhys Barnett (Imperial College London, UK) and Paul C. Hewett (U. Cambridge, UK)”.  This paper presents an automated, reproduceable and objective high-redshift quasar selection pipeline, tested on simulations and real data from the Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS). The overlay is here:

 

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

The third paper of the week is “Early Post Asymptotic Giant Branch Instability: Does it Affect White Dwarf Hydrogen Envelope Mass?” by James MacDonald (University of Delaware, USA). This one was published on Friday 1st Auguest (i.e. yesterday) in the folder Solar and Stellar Astrophysics. It is an investigation into whether Early Post AGB Instability (EPAGBI) can affect determinations of the total abundance of hydrogen in white dwarf stars.

The overlay is here:

The final version is on arXiv here.

 

The fourth paper of the week, also published on Friday 1st August, is “Light Echoes of Time-resolved Flares and Application to Kepler Data” by Austin King and Benjamin C. Bromley (University of Utah, USA).  This describes a new model for circumstellar disks that incorporates echoes produced by extended, time-resolved flares. It is published in the folder Solar and Stellar Astrophysics. Here is the overlay:

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

 

 

The fifth and final article published this week, also published on Friday 1st August,  is “Wide Binaries from Gaia DR3 : testing GR vs MOND with realistic triple modelling” by Charalambos Pittordis, Will Sutherland and Paul Shepherd (Queen Mary, University of London, UK). This presents a test for modified gravity from a sample of wide-binary stars from Gaia DR3, finding that (unmodified) Newtonian gravity provides a better fit to the data. It is in the folder Astrophysics of Galaxies.

The overlay is here:

 

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

And that’s all the papers for this week. I’ll do another update next Saturday.

Weekly Update from the Open Journal of Astrophysics – 19/04/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , , on April 19, 2025 by telescoper

It may be the Easter holiday weekend, but it’s still time for the weekly Saturday morning update of papers published at the Open Journal of Astrophysics. Since the last update we have published five new papers, which brings the number in Volume 8 (2025) up to 42 and the total so far published by OJAp up to 277.

In chronological order of publication, the five 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 “Galaxy Clustering with LSST: Effects of Number Count Bias from Blending” by Benjamin Levine (Stony Brook, NY), Javier Sánchez (STScI, MD), Chihway Chang (Chicago, IL) Anja von der Linden (Stony Brook), Eboni Collins (Dillard, LA), Eric Gawiser (Rutgers, NJ), Katarzyna Krzyżańska (Cornell, NY), Boris Leistedt (Imperial College, UK) on behalf of the LSST Dark Energy Science Collaboration.

This presents a simulation-based study of the effect of source overlaps (blending) on galaxy counts expected for the Vera C. Rubin Legacy Survey of Space and Time (LSST). The paper is in the folder Cosmology and NonGalactic Astrophysics and was published on Monday 14th April 2025. The overlay is here:

 

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

The second paper to announce, published onTuesday 15th April 2025,  “Rapid, strongly magnetized accretion in the zero-net-vertical-flux shearing box” by Jonathan Squire (Otago, New Zealand), Eliot Quataert (Princeton, USA) & Philip F. Hopkins (Caltech, USA). This  paper presents a numerical study of turbulence in a flux shearing box, with discussion of the implications of the results for global accretion disk models and simulations thereof. It was published in the folder High-Energy Astrophysical Phenomena and the overlay is here:

 

You can read the officially accepted version of this paper on arXiv here.

The third paper of the week, published on Wednesday April 16th 2025,   is “DeepDISC-photoz: Deep Learning-Based Photometric Redshift Estimation for Rubin LSST” by Grant Merz (University of Illinois at Urbana-Champaign, USA) and 13 others (all based in the USA) on behalf of the LSST Dark Energy Science Collaboration. This paper describes adding photometric redshift estimation to the DeepDISC framework for classification objects in co-added images for use with the Vera C. Rubin LSST survey. It can be found in the folder Instrumentation and Methods for Astrophysics.

Here is the overlay:

 

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

The next one to report is “Multidimensional Nova Simulations with an Extended Buffer and Lower Initial Mixing Temperatures” by Alexander Smith Clark and Michael Zingale (Stony Brook University, NY, USA). This paper presents new computer models of classical novae with improved ability to follow nucleosynthesis in the thermonuclear outburst and better treatment of convective transport. This one was also published on Wednesday 16th April 2025 but in the folder Solar and Stellar Astrophysics.

Here is the overlay:

 

The official published version can be found on the arXiv here.

The last paper of the five published this week is “Measurement of the power spectrum turnover scale from the cross-correlation between CMB lensing and Quaia” by David Alonso (Oxford, UK), Oleksandr Hetmantsev (Kyiv, Ukraine), Giulio Fabbian (Cambridge, UK), Anze Slosar (Brookhaven National Laboratory, USA) and Kate Storey-Fisher (Stanford, USA). This is a discussion of using the spatial correlations of quasars and their cross-correlations with cosmic microwave background lensing data to measure a feature corresponding to the matter-radiation equality scale with consequences for cosmological parameter estimation. It was published on Thursday 17th April 2025 in the folder Cosmology and NonGalactic Astrophysics.

The overlay is here:

You can find the officially accepted version on arXiv here.

That’s all the papers for this week. I’ll just add a couple of things.

One is that, although there have been weeks before in which we have published five or more papers, we still haven’t managed to have a week on which we’ve published a paper on every weekday. This week we had two on Wednesday 16th but didn’t have any yesterday (Friday).

The second is that tt has been a while since I last posted a breakdown of the running costs here at the Open Journal of Astrophysics. Today I received an email from Scholastica, our service provider, reminding me our costs will go up shortly (from 22nd April). In the interest of transparency I am passing this information on here.

The new prices will be as follows:

  • Peer Review System annual cost will be $425/year (was $350/year) plus $10 per submission (no change)
  • OA Publishing Platform annual cost will be $1,499/year (was $1,399/year)

Last year we published 120 papers with about 250 submissions. We’re a bit ahead of that this year, so I estimate that our next year’s costs will be a bit less than $5000. That’s still less than the typical APC for a single paper at many journals.

I hope this clarifies the situation.

Weekly Update from the Open Journal of Astrophysics – 01/02/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , on February 1, 2025 by telescoper

It’s Saturday morning, so once again it’s time for an update of papers published at the Open Journal of Astrophysics. There were no papers to report last week but since the last update we have published four new papers, which brings the number in Volume 8 (2025) up to 11 and the total so far published by OJAp up to 246.

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.

First one up is  “A halo model approach for mock catalogs of time-variable strong gravitational lenses” by Katsuya T. Abe & Masamune Oguri (Chiba U, Japan), Simon Birrer & Narayan Khadka (Stony Brook, USA), Philip J. Marshall (Stanford, USA), Cameron Lemon (Stockholm U., Sweden), Anupreeta More (IUCAA, India), and the LSST Dark Energy Science Collaboration. It was published on 27th January 2025 in the folder marked Cosmology and NonGalactic Astrophysics. The paper discusses how to generate mock catalogs of strongly lensed QSOs and Supernovae on galaxy-, group-, and cluster-scales based on a halo model that incorporates dark matter halos, galaxies, and subhalos.

 

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

This paper, also published on Monday 27th January 2025, but in the folder Astrophysics of Galaxies, is “The Soltan argument at redshift 6: UV-luminous quasars contribute less than 10% to early black hole mass growth” by Knud Jahnke (MPI Heidelberg, Germany). This paper presents an argument that almost all growth of supermassive black hole mass at z>6 does not take place in UV-luminous quasars.

Here is a screen grab of the overlay, which includes the abstract:You can find the officially accepted version of the paper on the arXiv here.

The third paper to announce, published on 29th January 2025 in the folder Cosmology and NonGalactic Astrophysics, is “A Heavy Seed Black Hole Mass Function at High Redshift – Prospects for LISA” by Joe McCaffrey & John Regan (Maynooth U., Ireland), Britton Smith (Edinburgh U., UK), John Wise (Georgia Institute of Technology, USA), Brian O’Shea (Michigan State U., USA) and Michael Norman (University of California, San Diego). This is a numerical study of the growth rates of massive black holes in the early Universe and implications for their detection via gravitational wave emission.

You can see the overlay here:

 

The accepted version of this paper can be found on the arXiv here.

The last paper of this batch is “Forecasting the Detection of Lyman-alpha Forest Weak Lensing from the Dark Energy Spectroscopic Instrument and Other Future Surveys” by Patrick Shaw & Rupert A. C. Croft (Carnegie Mellon U., USA) and R. Benton Metcalf (U. Bologna, Italy). This paper, published on January 30th 2025, is about extending the applicationof  Lyman-α forest weak gravitational lensing to lower angular source densities than has previously been done, with forecasts for future spectral surveys. It is in the folder marked Cosmology and NonGalactic Astrophysics.

The overlay is here

 

You can find the accepted version on arXiv here.

Incidentally, we currently have 121 papers under review, including 81 under a revise and resubmit request.

That’s all for this week. I’ll do another update next Saturday.

Two New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , on August 31, 2024 by telescoper

I am back in circulation after my little break and, since it’s Saturday, I will resume blogging with another report on activity at the  Open Journal of Astrophysics.  Since the last update we have published two more papers, taking  the count in Volume 7 (2024) up to 71 and the total published by OJAp up to 186.  We’ve still got a few in the pipeline waiting for the final versions to appear on arXiv so I expect we’ll reach the 200 mark fairly soon.

The first paper of the most recent pair, published on August 26th 2024,  is “Impact of lensing of gravitational waves on the observed distribution of neutron star masses”  by Sofia Canevarolo, Loek van Vonderen and Nora Elisa Chisari, all of Utrecht University in the Netherlands. This article presents a discussion of the bias in neutron star mass determinations caused by gravitational lensing of the gravitational waves they produceThe paper is in the folder marked Cosmology and NonGalactic Astrophysics.

Here is a screen grab of the overlay which includes the abstract:

 

You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.

The second paper has the title “FORGE’d in FIRE III: The IMF in Quasar Accretion Disks from STARFORGE” and was published (in the early hours of the morning) on 29th August 2024. The authors, all based in the USA, are Philip F. Hopkins (Caltech), Michael Y. Grudic (Carnegie Observatories), Kyle Kremer (Caltech), Stella S. R. Offner (UT Austin), David Guszejnov (UT Austin) and Anna L. Rosen (UCSD). This paper, which is in the folder marked Astrophysics of Galaxies, presents a numerical study of star formation and the initial mass function in quasar accretion disks. The previous two papers in this series have also been published in the OJAp: you can find them here and here; images and movies related to this project can be found here.

Here is a screen grab of the overlay which includes the abstract:

 

You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.

That concludes this week’s update. We still have quite a few papers in the pipeline after the summer lull so I expect I’ll have a larger update for you next week!

Three New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, The Universe and Stuff with tags , , , , , , , , , , , , , , , , on March 19, 2024 by telescoper

Now that I’m safely back in Barcelona it’s a time for a roundup of the latest business at the  Open Journal of Astrophysics. The latest batch of publications consists of three papers, taking the count in Volume 7 (2024) up to 20 and the total published by OJAp up to 135.

This time the papers are all related, have many authors in common, and have the same first author, Philip F. Hopkins of Caltech. In fact the second and third papers in this batch were accepted well before the first one, but it seemed to make much more sense to publish them together so I held those two back a bit and published all three on 14th March.

The three papers published, 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. You can read these publications directly on arXiv if you wish; you will find them here, here and here.

First one up is “FORGE’d in FIRE: Resolving the End of Star Formation and Structure of AGN Accretion Disks from Cosmological Initial Conditions” in which, using a full cosmological simulation, incorporating radiation and magnetohydrodynamics, the authors study the formation and structure of AGN accretion disks and their impact on star formation. This one is in the folder marked Astrophysics of Galaxies.

The authors (ten from the USA and one from Canada) are Philip F. Hopkins (Caltech), Michael Y. Grudic (Carnegie Observatories), Kung-Yi Su (Harvard), Sarah Wellons (Wesleyan University), Daniel Angles-Alcazar (University of Connecticut & Flatiron Institute), Ulrich P. Steinwandel (Flatiron Institute), David Guszejnov (University of Texas at Austin), Norman Murray (CITA, Toronto, Canada), Claude-Andre Faucher-Giguere (Northwestern University), Eliot Quataert (Princeton), and Dusan Keres (University of California, San Diego or UCSD for short).

Here is a screen grab of the overlay, which includes the abstract:

 

 

The second paper to announce is “FORGE’d in FIRE II: The Formation of Magnetically-Dominated Quasar Accretion Disks from Cosmological Initial Conditions” which is a study of the formation and properties of highly magnetized accretion disks using numerical simulations that include the effects of radiation, magnetic fields, thermochemistry, and star formation.

This one is in the folder High-Energy Astrophysical Phenomena. The authors (ten based in the USA, one fin Canada, and one in New Zealand) are Philip F. Hopkins, Jonathan Squire (University of Dunedin, New Zealand), Kung-Yi Su (Harvard), Ulrich P. Steinwandel (Flatiron Institute), Kyle Kremer (Caltech), Yanlong Shi (Caltech), Michael Y. Grudic (Carnegie Observatories), Sarah Wellons (Wesleyan University), Claude-Andre Faucher-Giguere (Northwestern University), Daniel Angles-Alcazar (University of Connecticut & Flatiron Institute), Norman Murray (CITA, Toronto), and Eliot Quataert (Princeton).

 

The last paper of this batch, also in the folder High-Energy Astrophysical Phenomena, is  entitled “An Analytic Model For Magnetically-Dominated Accretion Disks” and is closely related to the previous one; this particular paper presents an analytic similarity model for accretion disks that agrees remarkably well with the simulations in the previous one. Animations of the simulations referred to in both papers can be found here.

Here is the overlay:

The authors of this one are Philip F. Hopkins, Jonathan Squire, Eliot Quataert, Norman Murray, Kung-Yi Su, Ulrich P. Steinwandel, Kyle Kremer, Claude-Andre Faucher-Giguere, and Sarah Wellons. You can find all their affiliations above.
That’s all for now. More news in a week or so!

 

 

Two New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , on December 14, 2023 by telescoper

As anticipated a couple of days ago, it’s now possible to announce another couple of new papers at the Open Journal of Astrophysics. These papers take us up to a total of 49  in Volume 6 (2023) and 114 in total since we started publishing.

It would be nice if we could make it to 50 in Volume 6 (2023), but I have already decided to close the publishing platform from 22nd December until 5th January (inclusive), so there there isn’t much time to get the single needed for our half-century.  While we will not be publishing new papers during this closure, the peer review platform will remain open for submission of new and revised manuscripts and the editorial processes will continue.

Whether or not we make 50 this year, it is worth remarking that 49 is already a significant figure, as it corresponds to the total number of papers we published in the previous three years: 15 (2020); 17 (2021); and 17 (2022). Things are definitely looking up!

Anyway, the first paper of the most recent pair – published on December 8th – is “The Million Quasars (Milliquas) Catalogue, v8”; its primary classification is Astrophysics of Galaxies and the author is Eric Wim Flesch from New Zealand. The Milliquas catalogue includes quasars from the literature to 30 June 2023, including quasars from the DESI-EDR and SDSS-DR18Q surveys.

Here is a screen grab of the overlay which includes the abstract:

You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.

The second paper was published on 11th December 2023 and is also in the folder marked Astrophysics of Galaxies.

The authors are all from various institutions in the USA:  Michael Grudić (Carnegie Observatories), Stella Offner (University of Texas at Austin); Dávid Guszejnov (Harvard);  Claude-André Faucher-Giguère (Northwestern University); and Philip F. Hopkins (Caltech).  The paper presents a comparison of full radiative magnetohydrodynamics simulations of the formation of star clusters with simple stochastic modelling showing the limitations of the latter.

Here is a screen grab of the overlay which includes the abstract:

 

 

You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.

R.I.P. Maarten Schmidt (1929-2022)

Posted in History, R.I.P., The Universe and Stuff with tags , on September 20, 2022 by telescoper

Once again I find myself having to pass on some sad news. Astronomer Maarten Schmidt has passed away at the age of 92. The highlight of his long and distinguished career was the discovery, in 1963, that quasars showed hydrogen emission lines that revealed them to be at cosmological redshifts. Together with Donald Lynden-Bell (who passed away in 2018), Schmidt was awarded the inaugural Kavli Prize for Astrophysics in 2008.

Rest in peace, Maarten Schmidt (1929-2022).