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Euclid Update

Posted in Euclid, History, The Universe and Stuff on February 13, 2024 by telescoper

It’s a lovely sunny Saint Ash Valentine’s Wednesday Day in Australia though I’m not sure what day it is at the 2nd Lagrange Point of the Earth-Sun system. Nevertheless, as I mentioned last week, Euclid’s Wide Survey starts today; here is the official announcement of this from ESA. To mark this momentous event here is another nice video update showing the preparations that have been going on ahead of the arrival of the deluge of real data:

Among other things, you will see an appearance by Henry Joy McCracken whose namesake led the United Irishmen in the Rebellion of 1798.

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New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , on February 12, 2024 by telescoper

With all the excitement of my first weekend in Sydney I completely forgot to post an update from the Open Journal of Astrophysics. In fact there is only one paper to report from last week, being  the 12th paper in Volume 7 (2024)  and the 127th altogether. This one was published on 9th February 2024 and is the first published from Down Under.

The title is “Galaxy Clusters Discovered via the Thermal Sunyaev-Zel’dovich Effect in the 500-square-degree SPTpol Survey” and it presents a catalogue of 689 galaxy clusters detected through the thermal Sunyaev-Zel’dovich using the dual-frequency polarization-sensitive camera SPTPol on the South Pole Telescope. This one is in the folder called Cosmology and NonGalactic Astrophysics.

This paper has lead author Lindsey Bleem  of the Argonne National Laboratory in the USA and has 127 other authors – too many to list individually here – but you can see them on the overlay below. I see quite a few names of people I know well!

Here is the overlay of the paper containing 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.

P.S. Incidentally, while I’m here I thought I’d share this little graphic I’ve generated (for other purposes) that shows how the rate of submissions to OJAp has increased over the last 5 years:

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A Euclid Milestone!

Posted in Euclid, The Universe and Stuff with tags , , , , , , , , on February 9, 2024 by telescoper

I just heard some excellent news about Euclid so thought I would post a quick update here. I won’t say much because there will no doubt be official communications from the European Space Agency and the Euclid Consortium. You can find a variety of Euclid-related posts on this blog here.

Over the past few months, there has been a huge amount of activity relating to commissioning the instruments, verifying their performance, and measuring parameters of the optical system that will be needed for analysis of the huge amount of data due to come from Euclid. All this effort fed into the Mission Commissioning Results Review (MCRR) which concluded yesterday that all was well.

This is an important milestone for Euclid because, in ESA parlance, it marks the change from a project to a mission. Until commissioning, there is a project manager who works with ESA and the industrial contractors to ensure everything functions properly; when nominal operations start the project team is disbanded and the mission team takes over; and so it came to pass that the Project Manager (Giuseppe Racca) handed over the reins to the Mission Manager (Pierre Ferruit).

That’s when the role of the Euclid Consortium increases substantially. In particular the Science Ground Segment (SGS), which includes the pipelines that will process the data, has been declared to be ready for business. You can read more about the SGS here but here’s a graphic that shows how data comes from the telescope, external telescopes, or simulations, then run through their respective pipelines for VIS, NISP, or external data, then are merged into a coherent format. Pipelines then extract scientific information and compute science data products for further analysis

Each element of this diagram is rather complex. Here, for example, is the organization of the Science Data Centre (SDC) component of the Science Ground Segment at the bottom of the above picture, consisting of computing centers responsible for implementing and running the data processing pipelines:

Anyway, the immediate upshot of all this is that full surveying activities of Euclid can now proceed. The Euclid mission will conduct primarily two different surveys: a “Wide Survey”, covering about 15,000 square degrees on the sky, and a “Deep Survey” of about 50 square degrees, where the instruments will observe three fields much longer than the rest of the sky to capture much fainter galaxies and hence look further out into space. I understand that the Wide Survey will commence in earnest on 14th February.The timescale from now is that the first full set of survey data (DR1) will be available internally to the Euclid Consortium in May or June 2025 and will be made public a year later (i.e. by June 2026).

That doesn’t mean that Euclid will be silent until 2026. In fact, the first batch of post-launch papers will come out very soon, in May 2024. This will include science papers resulting from the Early Release Observations – the data from these will also be made public at the same time – as well as an overview paper for the whole mission and papers describing the details of NISP and VIS instruments using measurements made during commissioning. There will also be a release in May 2025 of data from the Deep Survey patch of about 50 square degrees.

So, the board is set. The pieces are moving.

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Masters in Theoretical Physics & Mathematics at Maynooth

Posted in Education, Maynooth, The Universe and Stuff with tags , , on February 6, 2024 by telescoper

Yesterday was a holiday in Ireland but now, with the January examinations over, it’s back to teaching. I am not in Maynooth to enjoy the fun but I can use the medium of this blog to advertise the fact that the MSc in Theoretical Physics & Mathematics is now open to applications for entry in September.

This postgraduate course is run jointly between the Departments of Theoretical Physics and Mathematics & Statistics, with each contributing about half the material. The duration is one calendar year (full-time) or two years (part-time) and consists of 90 credits in the European Credit Transfer System (ECTS). This is split into 60 credits of taught material (split roughly 50-50 between Theoretical Physics and Mathematics) and a research project of 30 credits, supervised by a member of staff in a relevant area from either Department.

This course is a kind of follow-up to the existing undergraduate BSc Theoretical Physics & Mathematics at Maynooth, also run jointly. We think the postgraduate course will appeal to many of the students on that programme who wish to continue their education to postgraduate level, though applications are very welcome from suitably qualified candidates who did their first degree elsewhere.

Postgraduate admissions in Ireland operate differently from the UK, in that there is a central system in Ireland (called PAC) that is similar to the undergraduate admissions system; in the UK PG courses are dealt with by individual institutions. You will need to apply online via PAC after the following the instructions here. The requisite PAC code for the full-time version of the course is MHQ56.

The closing date for applications is 30th June 2024.

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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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