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Two New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , on February 5, 2024 by telescoper

Now that I’m settled in Sydney it’s time to post another update relating to the  Open Journal of Astrophysics.  Since the last update we have published two more papers, taking  the count in Volume 7 (2024) up to 11 and the total published by OJAp up to 126. I should have posted these before leaving but it slipped my mind.

Both the current papers discussed here are in the folder marked Cosmology and NonGalactic Astrophysics, our most popular category.

Anyway, the first paper of the most recent pair – published on February 1st – is “LimberJack.jl: auto-differentiable methods for angular power spectra analyses”, Jaime Ruiz-Zapatero (Oxford, UK), David Alonso (Oxford, UK), Carlos García-García (Oxford, UK) , Andrina Nicola (Bonn, Germany), Arrykrishna Mootoovaloo (Oxford, UK), Jamie Sullivan (Berkeley, USA), Marco Bonici (Milan, Italy), and Pedro Ferreira (Oxford, UK). This paper presents a fully auto-differentiable code for cosmological analyses of two-point auto- and cross-correlation measurements from galaxy clustering, CMB lensing and weak lensing data written in Julia.

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 Friday 2nd February and has the title “Can we constrain structure growth from galaxy proper motions?” which, as its title suggests, looks at the feasibility of using transverse peculiar velocities (i.e. proper motions) of galaxies for cosmological studies. The authors are Iain Duncan (Oxford, UK), David Alonso (Oxford, UK), Anže Slosar (Brookhaven National Laboratory, USA), and Kate Storey-Fisher (New York University, USA). To find out the answer to the question posed in its title you’ll have to read the paper!

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.

Because of the high rate of publications coming out, we’re moving to a system where we register papers in batches once a week rather than individually as they are published. This is just a temporary measure until we can automate this process more fully. Anyway, you can expect another update in a week or so.

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Two New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , on February 1, 2024 by telescoper

As the first month of 2024 is now over, I thought I’d post an update relating to the  Open Journal of Astrophysics.  Since the last update we have published two papers, taking  the count in Volume 7 (2024) up to 9 (the total for January) and the total published by OJAp up to 124. We will have others soon, but I will be travelling for the first few days of February so the next update will be in a week or so.

Using our sophisticated forecasting algorithm, based on the first month of 2024 as input, I predict that we will publish around 9×12=108 papers in 2024, more than double last year’s total of 50.

Both the current papers discussed here are in the folder marked Cosmology and NonGalactic Astrophysics, our most popular category.

Anyway, the first paper of the most recent pair – published on January 30th – is “Capse.jl: efficient and auto-differentiable CMB power spectra emulation”, by Marco Bonici (INAF Milano, Italy & Waterloo, Canada), Federico Bianchini (Stanford, USA) and Jaime Ruiz-Zapatero (Oxford, UK). This paper presents an emulator for rapid and accurate prediction of Cosmic Microwave Background (CMB) temperature, polarization, and lensing angular power spectra, that works much faster than traditional methods. The code is written in Julia, in which language we are seeing an increasing number of submissions to OJAp.

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 yesterday (31st January 2024) and has the title “Cosmological Inflation in N-Dimensional Gaussian Random Fields with Algorithmic Data Compression” which is a  study of inflationary models with Gaussian random potentials for multiple scalar fields, tracking the evolutionary trajectories numerically. The authors are Connor Painter and Emory Bunn, both the Physics Department at the University of Richmond, Virginia (USA). Ted Bunn (as he is usually known) is a longstanding member of the Editorial Board of the Open Journal of Astrophysics (and was thereby excluded from any involvement in the editorial process for this paper).

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.

Here Endeth the Update.

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PHANGS for the galaxies…

Posted in The Universe and Stuff with tags , , , , , , , on January 31, 2024 by telescoper

I couldn’t resist sharing this wonderful set of images from JWST courtesy of the PHANGS* team showing exquisite details of 19 face-on spiral galaxies as seen in the infra-red:

More information about the remarkable structures seen in these images, as well as higher resolution versions of the images themselves, can be found on the European Space Agency website here.

*For those of you not in the know, PHANGS stands for Particularly Horrible Acronym Not Generated Sensibly Physics at High Angular resolution in Nearby GalaxieS.

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The Little Book of Irish Research

Posted in Euclid, Maynooth, The Universe and Stuff with tags , on January 30, 2024 by telescoper

A few months ago, I blogged on the occasion of the launch by Simon Harris TD, Minister for Further and Higher Education, Research, Innovation and Science, of the Little Book of Irish Research. This book, which is aimed at school students, so is written at an elementary level, gives quick summaries of areas of research that the general public said that they were interested in, grouped into sixteen themes, and it will be distributed to schools all round Ireland.

if you want to read it here is a PDF file of the whole thing for you to download at your leisure. When I posted about it last time I hadn’t actually seen a hard copy, but I finally got my hands on one:

I can now confirm that it is indeed a little book. I think we’ll find it useful for our own outreach events, open days, etc, in the Department of Theoretical Physics, and so will the many colleagues in other Departments in other universities and research institutes whose work is also featured.

I was very gratified to see myself get a mention (on page 41), though it’s not really about me but about Euclid which has generated considerable interest in the general public already and is set to continue doing that for many years. As you can see, there’s also a double-page spread of JWST, though unfortunately it does not name the scientists involved; Paddy Kavanagh is the main man at Maynooth for matters JWST.

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The Reinvention of Science

Posted in History, Literature, The Universe and Stuff with tags , , , , , on January 28, 2024 by telescoper

I’ve known about the existence of this new book for quite a long time – the first two of the authors are former collaborators of mine and I’m still in fairly regular touch with them – but I only received a copy a few weeks ago. Had I been less busy when it was in proof stage I might have been in a position to add to the many generous comments on the back cover from such luminaries as Martin Rees, Jim Peebles, Alan Heavens and, my hosts in Barcelona, Licia Verde and Raúl Jiménez. Anyway, now that I’ve read it I’m happy to endorse their enthusiastic comments and to give the book a plug on this blog.

One can summarize The Reinvention of Science as a journey through the history of science from ancient times to modern, signposted by mistakes, fallacies and dogma that have hindered rather than facilitated progress. These are, in other words, not so much milestones as stumbling blocks. Examples include the luminiferous aether and phlogiston to name but two. These and many other case studies are used to illustrate, for example, how supposedly rational scientists sometimes hold very irrational beliefs and act accordingly on them. The book presents a view of the evolution of science in spite of the suppression of heterodox ideas and the desire of establishment thinkers to maintain the status quo.

The volume covers a vast territory, not limited to astrophysics and cosmology (in which fields the authors specialize). It is a very well-written and enjoyable read that is strong on accuracy as well as being accessible and pedagogical. I congratulate the authors on a really excellent book.

P.S. I am of course sufficiently vain that I looked in the index before reading the book to see if I got a mention and was delighted to see my name listed not once but twice. The first time is in connection with the coverage of the BICEP2 controversy on this very blog, e.g. here. I am pleased because I did feel I was sticking my head above the parapet at the time, but was subsequently vindicated. The second mention is to do with this article which the authors describe as “beautiful”. And I didn’t even pay them! I’m truly flattered.

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Three New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , on January 27, 2024 by telescoper

Once again it’s a good time for a roundup of the week’s business at the  Open Journal of Astrophysics. This past week we have once again published three papers, taking  the count in Volume 7 (2024) up to 7 and the total published by OJAp up to 122. Looking at the current work flow I expect there to be at least three next week too.

In chronological order, the three 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 “The extraordinary frequency pattern variation in δ Scuti stars” by  Luis A. Balona of the South African Astronomical Observatory in Cape Town, South Africa. This paper, published on 22nd  January 2024, is a study of the (lack of) correlation in the structure of periodograms in Transiting Exoplanet Survey Satellite (TESS) data relating to a oscillating delta Scuti variable stars. This paper is in the category of Solar and Stelllar Astrophysics.

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 second paper to announce is “The Millions of Optical-Radio/X-ray Associations (MORX) Catalogue, v2” by Eric Wim Flesch, an independent researcher based in New Zealand.  This presents the MORX catalogue of optical/radio/X-ray/ galaxy associations, containing over three million objects. The catalogue itself can be found in a number of locations on the web, e.g. here or here.

The paper was also published on 23rdJanuary 2024 in the category Astrophysics of Galaxies . 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  entitled “The runaway velocity of the white dwarf companion in the double detonation scenario of supernovae” and the authors are Jessica Braudo and Noam Soker of Technion, Haifa, in Israel.  This paper, which presents a study of ejection velocities in the double-detonation scenario of Type 1a Supernovae was published on 24th January 2024 and is in the folder marked High-Energy Astrophysical Phenomena.

Here is the overlay:

 

 

You can find the full text for this one on the arXiv here.

And that concludes the update.  As you can see, we’re getting a bit more diverse in terms of subject matter, which is nice. There’ll be more next week!

 

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LISA adopted by ESA

Posted in Science Politics, The Universe and Stuff with tags , , , , on January 25, 2024 by telescoper

I have some good news for gravitational-wave physicists to pass on. The European Space Agency (ESA) has formally “adopted” the Laser Interferometric Space Experiment (LISA) – a gravitational wave experiment in space. This follows the detection of gravitational waves using the ground-based experiment Advanced LIGO and the success of a space-based technology demonstrator mission called Lisa Pathfinder. LISA was actually selected as a potential mission in 2017 – see here – but “adoption” means that the mission concept and technology required are now both sufficiently advanced that it can proceed in 2025, once contractors are found to actually build it.

LISA consists of a flotilla of three spacecraft in orbit around the Sun forming the arms of an interferometer with baselines of the order of 2.5 million kilometres, much longer than the ~1km arms of Advanced LIGO. These larger dimensions make LISA much more sensitive to long-period signals. Each of the LISA spacecraft contains two telescopes, two lasers and two test masses, arranged in two optical assemblies pointed at the other two spacecraft. This forms Michelson-like interferometers, each centred on one of the spacecraft, with the platinum-gold test masses defining the ends of the arms.

Here’s an artist’s impression of LISA:

This is excellent news for the gravitational waves community, especially since LISA was threatened with the chop when NASA pulled out in 2011. Space experiments are huge projects – and LISA is more complicated than most – so it will take some time before it actually happens. The first I heard of the LISA concept was back in the mid-1990s and at the moment LISA is pencilled in for launch in 2035, so it will be forty years in the development.

Ireland is a full member of ESA so let’s hope the Irish Government finds a way of funding participation in the LISA mission. Although Ireland joined ESA nearly fifty years ago, and is paying  into the mandatory science programme which includes LISA (and, for example, Euclid), there is no funding programme in Ireland dedicated to the scientific exploitation of ESA projects. Let’s hope the Irish scientists involved in LISA – including those at Maynooth – are able to play a full part in this exciting project.

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R.I.P. Arno Penzias (1933-2024)

Posted in History, R.I.P., The Universe and Stuff with tags , , , on January 24, 2024 by telescoper

Yesterday I heard the sad news of the death, at the age of 90, of American physicist and radio astronomer Arno Penzias.

I’ve used the above image hundreds of times in popular talks. It shows Robert W. Wilson (left) and Arno A. Penzias (right) standing in front of the famous horn antenna that (accidentally) discovered what we now know to be the cosmic microwave background, radiation left over after the Big Bang.

Penzias and Wilson made their historic measurements in 1964, published their results in 1965, and received the Nobel Prize for Physics in 1978. At the time of this experiment, the scientists were working at Bell Telephone Laboratories at Holmdel, New Jersey, on Project Echo. The antenna was built to receive radio signals bounced off a passive satellite in a low Earth orbit to check the feasibility of satellite radio communication. They found excess noise in their receiver, which was eventually identified as a relic of a time when the Universe was extremely hot. Coincidentally, the theory of this yet undiscovered radiation was being worked on by Bob Dicke and his group in Princeton at about the same time (and also in New Jersey). Discussions ensued, and the discovery paper by Penzias & Wilson appeared in the Astrophysical Journal in 1965 beside a paper by Dicke et al. giving the theoretical interpretation.

The discovery of the cosmic microwave background was probably the most important result in observational cosmology after that of the Hubble expansion and it paved the way for the establishment and further development of the Big Bang theory. One of the two discoverers of the CMB has now left us, leaving a priceless legacy.

Rest in peace, Arno Allan Penzias (1933-2024)

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Spring School on Topological Aspects of Low-dimensional Quantum Physics at Maynooth!

Posted in Maynooth, The Universe and Stuff with tags , , on January 23, 2024 by telescoper

I’ve been asked by colleagues not in Barcelona to use the medium of this blog to advertise the fact that Maynooth University is hosting an exciting spring school for Early Career Researchers this April:

Registration is now open!

For further information and to register see here. Please forward to anyone who might be interested!

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Three New Publications at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , on January 20, 2024 by telescoper

As promised yesterday, it’s time for a roundup of the week’s business at the  Open Journal of Astrophysics. This past week we have published three papers, taking  the count in Volume 7 (2024) up to 4 and the total published by OJAp up to 119. There are quite a few more ready to go as people return from the Christmas break.

In chronological order, the three 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 “Prospects for studying the mass and gas in protoclusters with future CMB observations” by  Anna Gardner and Eric Baxter (Hawaii, USA), Srinivasan Raghunathan (NCSA, USA), Weiguang Cui (Edinburgh, UK), and Daniel Ceverino (Madrid, Spain). This paper, published on 17th January 2024, uses realistic hydrodynamical simulations to probe the ability of CMB Stage 4-like (CMB-S4) experiments to detect and characterize protoclusters via gravitational lensing and the Sunyaev-Zel’dovich effect. This paper is in the category of Cosmology and Nongalactic Astrophysics.

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 second paper to announce is “SDSS J125417.98+274004.6: An X-ray Detected Minor Merger Dual AGN” and is by Marko Mićić, Brenna Wells, Olivia Holmes, and Jimmy Irwin (all of the University of Alabama, USA).  This presents the discovery of a dual AGN in a merger between the galaxy SDSS J125417.98+274004.6 and dwarf satellite, studied using X-ray observations from the Chandra satellite. The paper was also published on 18th January 2024 in the category Astrophysics of Galaxies . 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  entitled “Population III star formation: multiple gas phases prevent the use of an equation of state at high densities” and the authors are:  Lewis Prole (Maynooth, Ireland), Paul Clark (Cardiff, UK), Felix Priestley (Cardiff, UK), Simon Glover (Heidelberg, Germany) and John Regan (Maynooth, Ireland). This paper, which presents a comparison of results obtained using chemical networks and a simpler equation-of-state approach for primordial star formation (showing the limitations of the latter) was published on 19th January 2024 and also in the folder marked Astrophysics of Galaxies.

Here is the overlay:

 

You can find the full text for this one on the arXiv here.

And that concludes the update. There’ll be more next week!

 

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