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1. Observations of a Magellanic Corona

   https://doi.org/10.1038/s41586-022-05090-5  

   Krishnarao, Dhanesh; Fox, Andrew J.; D’Onghia, Elena; Wakker, Bart P.; Cashman, Frances H.; Howk, J. Christopher; Lucchini, Scott; French, David M.; Lehner, Nicolas (September 2022, Nature)

   Abstract The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are the closest massive satellite galaxies of the Milky Way. They are probably on their first passage on an infalling orbit towards our Galaxy 1 and trace the continuing dynamics of the Local Group 2 . Recent measurements of a high mass for the LMC ( M halo  ≈ 10 11.1–11.4   M ⊙ ) 3–6 imply that the LMC should host a Magellanic Corona: a collisionally ionized, warm-hot gaseous halo at the virial temperature (10 5.3–5.5  K) initially extending out to the virial radius (100–130 kiloparsecs (kpc)). Such a corona would have shaped the formation of the Magellanic Stream 7 , a tidal gas structure extending over 200° across the sky 2,8,9 that is bringing in metal-poor gas to the Milky Way 10 . Here we show evidence for this Magellanic Corona with a potential direct detection in highly ionized oxygen (O +5 ) and indirectly by means of triply ionized carbon and silicon, seen in ultraviolet (UV) absorption towards background quasars. We find that the Magellanic Corona is part of a pervasive multiphase Magellanic circumgalactic medium (CGM) seen in many ionization states with a declining projected radial profile out to at least 35 kpc from the LMC and a total ionized CGM mass of log 10 ( M H II,CGM / M ⊙ ) ≈ 9.1 ± 0.2. The evidence for the Magellanic Corona is a crucial step forward in characterizing the Magellanic group and its nested evolution with the Local Group. 

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2. Field Observations of Surfzone Vorticity

   https://doi.org/10.1029/2024GL111402  

   Dooley, C; Elgar, Steve; Raubenheimer, Britt (October 2024, Geophysical Research Letters)

   Abstract In the surfzone, breaking‐wave generated eddies and vortices transport material along the coast and offshore to the continental shelf, providing a pathway from land to the ocean. Here, surfzone vorticity is investigated with unique field observations obtained during a wide range of wave and bathymetric conditions on an Atlantic Ocean beach. Small spatial‐scale [O(10 m)] vorticity estimated with a 5 m diameter ring of 14 current meters deployed in ∼2 m water depth increased as the directional spread of the wave field increased. Large spatial‐scale [O(100 m)] vorticity calculated from remote sensing estimates of currents across the surfzone along 200 m of the shoreline increased as alongshore bathymetric variability (channels, bars, bumps, holes) increased. For all bathymetric conditions, large‐scale vorticity in the inner surfzone was more energetic than in the outer surfzone. 

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3. Clustering of Global Magnetospheric Observations

   https://doi.org/10.1029/2024JH000221  

   Edmond, James; Raeder, Joachim; Ferdousi, Banafsheh; Argall, Matthew; Innocenti, Maria Elena (December 2024, Journal of Geophysical Research: Machine Learning and Computation)

   Abstract The use of supervised methods in space science have demonstrated powerful capability in classification tasks, but purely unsupervised methods have been less utilized for the classification of spacecraft observations. We use a combination of unsupervised methods, being principal component analysis, Self‐Organizing Maps, and hierarchical agglomerative clustering, to classify THEMIS and MMS observations as having occurred in the magnetosphere, magnetosheath, or the solar wind. The resulting classification are validated visually by analyzing the distribution of classifications and studying individual time series as well as by comparison to the labeled data set of a previous model, against which ours has an accuracy of 99.4. The model has a variety of applications beyond region classification such as deeper hierarchical analysis, magnetopause and bow shock crossing identification, and identification of bursty bulk flows, hot flow anomalies, and foreshock bubbles. 

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4. Radio Observations of Solar Flares

   Gary, D. E.; Bastian, T. S.; Chen, B.; Fleishman, G. D.; Glesener, L. (January 2018, Science with a Next Generation Very Large Array, ASP Conference Series, Vol. 517. ASP Monograph 7.)
5. LMT/AzTEC observations of Vega

   https://doi.org/10.1093/mnras/stac1510  

   Marshall, J P; Chavez-Dagostino, M; Sanchez-Arguelles, D; Matrà, L; del Burgo, C; Kemper, F; Bertone, E; Dent, W_R F; Vega, O; Wilson, G; et al (June 2022, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT Vega is the prototypical debris disc system. Its architecture has been extensively studied at optical to millimetre wavelengths, revealing a near face-on, broad, and smooth disc with multiple distinct components. Recent millimetre-wavelength observations from ALMA spatially resolved the inner edge of the outer, cold planetesimal belt from the star for the first time. Here we present early science imaging observations of the Vega system with the AzTEC instrument on the 32-m LMT, tracing extended emission from the disc out to 150 au from the star. We compare the observations to three models of the planetesimal belt architecture to better determine the profile of the outer belt. A comparison of these potential architectures for the disc does not significantly differentiate between them with the modelling results being similar in many respects to the previous ALMA analysis, but differing in the slope of the outer region of the disc. The measured flux densities are consistent between the LMT (single dish) and ALMA (interferometric) observations after accounting for the differences in wavelength of observation. The LMT observations suggest the outer slope of the planetesimal belt is steeper than was suggested in the ALMA analysis. This would be consistent with the interferometric observations being mostly blind to structure at the disc outer edges, but the overall low signal to noise of the LMT observations does not definitively resolve the structure of the outer planetesimal belt. 

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