Archive for Stellar streams

Weekly Update from the Open Journal of Astrophysics – 07/06/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , on June 7, 2025 by telescoper

It’s Saturday so once again it’s time for the weekly update of papers published at the Open Journal of Astrophysics. Since the last update we have published two new papers, which brings the number in Volume 8 (2025) up to 69 and the total so far published by OJAp  is now up to 304.

The two 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 “Chemical Abundances in the Leiptr Stellar Stream: A Disrupted Ultra-faint Dwarf Galaxy?” by Kaia R. Atzberger (Ohio State University) and 13 others based in the USA, Germany, the UK, Sweden, Australia, Canada and Brazil. This one was published on 2nd June 2025 and is in the folder marked Astrophysics of Galaxies. It presents a spectroscopic study of stars in a stellar stream suggesting that the stream originated by the accretion of a dwarf galaxy by the Milky Way.

The overlay is here:

 

You can read the final accepted version on arXiv here.

The second paper is “Scaling Laws for Emulation of Stellar Spectra” by Tomasz Różański (Australian Nastional University) and Yuan-Sen Ting (Ohio State University, USA). This was published yesterday, i.e. on 6th June 2025, and is in the folder Instrumentation and Methods for Astrophysics. The paper discusses certain scaling models and their use to achieve optimal performance for neural network emulators in the inference of stellar parameters and element abundances from spectroscopic data.

The overlay is here:

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

That’s the papers for this week. I’ll post another update next weekend.

As a postscript I have a small announcement about our social media. Owing to the imminent demise of Astrodon, we have moved the Mastodon profile of the Open Journal of Astrophysics to a new instance, Fediscience. You can find us here. The old profile currently redirects to the new one, but you might want to update your links as the old server will eventually go offline.

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Weekly Update from the Open Journal of Astrophysics – 22/02/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , on February 22, 2025 by telescoper

It’s Saturday morning again so it’s time for an update of papers published at the Open Journal of Astrophysics. Things have picked up a bit after a quiet couple of weeks. Since the last update we have published four new papers which brings the number in Volume 8 (2025) up to 18 and the total so far published by OJAp up to 253.

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.

The first paper to report is in fact our 250th paper:  “Untangling Magellanic Streams” by Dennis Zaritsky (Steward Observatory), Vedant Chandra (Harvard), Charlie Conroy (Harvard), Ana Bonaca (Carnegie Observatories), Phillip A. Cargile (Harvard), and Rohan P. Naidu (MIT), all based in the USA. This paper is in the folder marked Astrophysics of Galaxies and it reports on spectroscopic study aimed at teasing out the stellar populations of different strands of the Magellanic Stream. It was published on Tuesday 18th February 2025. Here is the overlay:

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

The second paper of the week  is “Compressed ‘CMB-lite’ Likelihoods Using Automatic Differentiation” by Lennart Balkenhol (Institut d’Astrophysique de Paris, France) which was one of two papers published on Wednesday 19th February. It appears in the folder Cosmology and Nongalactic Astrophysics and it describes an implementation of the CMB-lite framework relying on automatic differentiation to reduce the computational cost of the lite likelihood construction.  The overlay is here:

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

The next paper, also published on Wednesday 19th February in the folder Cosmology and Nongalactic Astrophysics is “Bayesian distances for quantifying tensions in cosmological inference and the surprise statistic” by Benedikt Schosser (Heidelberg, Germany), Pedro Riba Mello & Miguel Quartin (Rio de Janeiro, Brazil) and Bjoern Malte Schaefer (Heidelberg).  It presents a discussion of statistical divergences applied to posterior distributions following from different data sets and their use in quantifying discrepancies or tensions.

Here is the overlay:

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

Finally in this batch we have “Precise and Accurate Mass and Radius Measurements of Fifteen Galactic Red Giants in Detached Eclipsing Binaries” by Dominick M. Rowan,  Krzysztof Z. Stanek,  Christopher S. Kochanek & Todd A. Thompson (Ohio State University), Tharindu Jayasinghe (independent researcher),  Jacqueline Blaum (UC Berkeley),  Benjamin J. Fulton (NASA/Caltech),  Ilya Ilyin (AIP Potsdam, Germany),  Howard Isaacson, Natalie LeBaron  &  Jessica R. Lu (UC Berkeley), and  David V. Martin (Tufts University, USA).  This paper was published on Thursday 20th February 2025 in the folder Solar and Stellar Astrophysics and it presents a compilation of mass and readius measurements of red giant stars obtained using spectroscopic measurements together with light curves and the eclipsing binary models obtained using PHOEBE.

The overlay is here:

You can find the “final” version on arXiv here.

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

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