Archive for the OJAp Papers Category

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Cosmology Talks: Intrinsic Alignments – A Guide for All Cosmologists

Posted in OJAp Papers, The Universe and Stuff, YouTube with tags , , , , , , , , , on February 24, 2024 by telescoper

I was just thinking this afternoon that I haven’t posted recently any of the Cosmology Talks curated by Shaun Hotchkiss, then I looked and found that I had the perfect excuse for doing so. This particular talk is actually about one of the two new OJAp papers I announced in my previous post, i.e. “The IA Guide: A Breakdown of Intrinsic Alignment Formalisms” and the authors are: Claire Lamman (Harvard, USA);  Eleni Tsaprazi (Stockholm, Sweden);  Jingjing Shi (Tokyo, Japan); Nikolina Niko Šarčević (Newcastle, UK); Susan Pyne (UCL, UK); Elisa Legnani (Barcelona, Spain); and Tassia Ferreira (Oxford, UK).

Here is Shaun’s description of the video:

Claire Lamman, Jingjing Shi, Niko Šarčević, Susan Pyne, Elisa Legnani and Tassia Ferreira tell us about the intrinsic alignments guide they wrote (along with Eleni Tsaprazi, who couldn’t make the video recording).

They wanted to write something that wasn’t quite a review, but also wasn’t quite a set of lecture notes. Instead they aimed for what might be best framed as a “cheat sheet” for intrinsic alignments. Everything you need to know about the topic, compressed into one article. However, there’s still a lot about the topic, so the compression is still 33 pages and 10 figures big.

To construct the guide they broke the topic of intrinsic alignments into sub-fields and then asked questions like “what are the key equations for this sub-field?”, “what are the different notations people use?”, “what might be confusing to a newcomer?” They then wrote the guide to answer those questions, even including subsections with quick definitions of each common term, and short lists of common alternative notations.

And here is the video!

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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 24, 2024 by telescoper

It’s Saturday morning in Sydney, and 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 15 and the total published by OJAp up to 130. I should have posted these before leaving but it slipped my mind.

The first paper of the most recent pair – published on  Thursday 22nd February – is “Modelling cross-correlations of ultra-high-energy cosmic rays and galaxies” by Federico Urban (Prague, Czech Republic), Stefano Camera (Torino, Italy) and David Alonso (Oxford, UK). It presents a discussion of the possible statistical correlations between Ultra-High-Energy Cosmic-Ray (UHECR) directions in various models and structure in the galaxy distribution and whether or not this signal could be measurable.  This one is in the folder marked “High-Energy Astrophysical Phenomena“.

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 23rd February and has the title “The IA Guide: A Breakdown of Intrinsic Alignment Formalisms” and the authors are: Claire Lamman (Harvard, USA);  Eleni Tsaprazi (Stockholm, Sweden);  Jingjing Shi (Tokyo, Japan); Nikolina Niko Šarčević (Newcastle, UK); Susan Pyne (UCL, UK); Elisa Legnani (Barcelona, Spain); and Tassia Ferreira (Oxford, UK). This one, which is in the folder marked Cosmology and NonGalactic Astrophysics, presents a review of Intrinsic Alignments, i.e. physical correlations involving galaxy shapes, galaxy spins, and larger scale structure, especially important for weak gravitational lensing

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!

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Talking Down Under

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

This morning I gave a short talk at the “Astronomy Tea” at the Sydney Institute for Astronomy. No prizes for guessing what I talked about. The talk was followed by questions and then by a huge thunderstorm.

Here are the slides:

P.S. Today was the first day of teaching of the new academic year at the University of Sydney, so the campus was much busier today than it has been.

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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 16, 2024 by telescoper

It’s Saturday morning here in Sydney, which means it is time for another weekly update from the Open Journal of Astrophysics. In fact there is only one paper to report this week, being  the 13th paper in Volume 7 (2024)  and the 128th altogether. It was published on February 15th 2024.

The title is “Jet – counter-jet asymmetry in the jittering jets explosion mechanism of supernovae” and it  This one is in the folder called High-Energy Astrophysical Phenomena. The paper presents a discussion of the production of jets in core-collapse supernovae and the resulting formation of neutron stars, and the implications for the morphology of the supernova remnant.

The sole author of the paper is Noam Soker of Technion, Haifa, in Israel.

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.

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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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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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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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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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New Publication at the Open Journal of Astrophysics

Posted in OJAp Papers, The Universe and Stuff with tags , , , on January 11, 2024 by telescoper

Well, it’s 2024 and time to start a new volume – the seventh – of the Open Journal of Astrophysics with the very first paper of the new year. The paper in question is the 1st paper in Volume 7 (2024)  and the 116th altogether. This one was published on 8th January 2024.

The title is “A new timestep criterion for N-body simulations” and it presents a new method for estimating characteristic dynamical timescales in N-body simulations, based on derivatives up to fourth order, which can be used to adjust timesteps used in numerical computations. The paper is in the folder marked Earth and Planetary Astrophysics as the paper discusses applications to orbital dynamics in planetary systems, but the method is of much wider applicability.

The authors are Dang Pham & Hanno Rein  (University of Toronto, Canada) and David S. Spiegel (Google, USA).

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.

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