RAS Journals

Graphic promoting the Specialist Discussion Meeting 'Gravitationally unstable protostellar discs and their role in planet formation'.

Or perhaps our Specialist Discussion Meeting on the role that gravitationally unstable protostellar discs play in planet formation is more up your street? 🪐

If so, don't delay, secure your spot either in-person or online by scanning the QR code or visiting: ras.ac.uk/events-and-m...

Graphic promoting the RAS Specialist Discussion Meeting 'The Next Generation of Modelling and Observing Techniques for the Lower Solar Atmosphere'.

🔊 Final call! 🔊

Time is running out to book your tickets for this Friday's Specialist Discussion Meetings. ⌛️

Interested in finding out more about developments in how we observe the lower solar atmosphere? ☀️ Scan the QR code on the graphic below for ℹ️ or 🎟️ in-person & online.

Professor Mike Cruise. Credit: Lucinda Douglas Menzies.

The RAS was saddened to hear of the passing of our former President, Professor Mike Cruise, who has died aged 78.

"Kind, thoughtful and honourable", Mike was a "stalwart of the RAS". Our thoughts are with his family, friends and all who had the privilege to know him.

ras.ac.uk/news-and-pre...

Distribution of dark matter haloes (black) derived from CSiBORG, overlaid with NSA galaxies (purple; left panel), ALFALFA galaxies (magenta; right panel) and cosmic web filaments (blue), shown in a 15 Mpc slice along the z-axis centred on the Milky Way. The cosmic web filaments are calculated using DisPerSE, applied to the CSiBORG haloes. NSA and ALFALFA galaxies predominantly cluster along the filamentary structures, with some galaxies distributed within the voids of the cosmic web. See Section 2.1 for details on the CSiBORG haloes, and Section 3.2 for further details on the DisPerSE methodology and filament extraction.

Published in #MNRAS: "The galaxy–environment connection revealed by constrained simulations", Gallagher et al. This is Fig. 3: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Overview of the mountain permafrost sites located in the Swiss-, Austrian-, Italian and German- Alps with the location of the spectral induced polarization (SIP) profiles and the electrical resistivity tomography monitoring (ERTM) profiles marked as lines. At sites where the SIP and ERTM profiles coincide, only one line is shown. The sites comprise bedrock permafrost sites (BR), rock glaciers (RG) talus slopes (TS) and pure ice (IC).

Published in #GJI Geophysical Journal International: "Spectral induced polarization measurements at different mountain permafrost landforms with varying ice contents", Maierhofer et al. Please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Diagram of the training loop: In a clockwise fashion; the source function is initiated to the Planck function B, which is then sent to the agent as a state. The agent’s policy decides on an action that generates four parameters p that are used to construct a smooth, well-behaved source function across the entire depth scale. The agent’s predicted solution is passed to the physics engine, which generates a conditioned ‘implied’ source function that would satisfy SE. The residual of the agent and implied source is used as a reward signal to instruct the agent’s policy. The inner loop iterates until either a max step criterion is reached or the agent obtains the target, defining a single episode. Once the inner loop terminates, the source function is once again initiated to the Planck function, and the agent can try and refine its policy.

Published in #RASTI RAS Techniques & Instruments: "Solving the 2-level atom non-LTE problem using soft actor-critic reinforcement learning", Panos & Milić. Please visit academic.oup.com/rasti/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

The spectra of the [O III] emission line of HerBS-28, -90, -103, and -160. Please read the paper for the full caption.

Published in #MNRAS: "Breathless BEARS: [O III] 88 µm emission of dusty star-forming galaxies at z = 3−4", Bakx et al. This is Fig. 1: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Model setup for case with along-strike variation in interface viscosity. Panel (A) shows the surface overlying a slice taken from F to F’, coloured by viscosity and composition. Panels (B) and (C) show strength and temperature profiles of the subducting and overriding plate, respectively.

Published in #GJI Geophysical Journal International: "The role of along-strike variations in interface rheology on subduction dynamics: constraints from three-dimensional numerical models", Neuharth et al. Please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social

Comoving cosmic star formation rate density in the redshift range 0 ≤ ⁠z ≤ 59. Please see the paper for the full caption.

Published in #RASTI RAS Techniques & Instruments: "ECHO21: a tool for modelling global 21-cm signal from dark ages to reionization", Mittal et al. This is Fig. 1: for the caption & to read the paper please visit academic.oup.com/rasti/articl...

The mass–metallicity relation for observed satellites of the Milky Way (blue points) and M31 (orange points). We provide a linear fit to these satellites (solid) and the relation from E. N. Kirby et al. (2013) (dashed). We also highlight individual satellites known or believed to be disrupting and their reconstructed ‘total’ values (star symbols, see the text for details).

Published in #MNRAS: "Auriga Streams III: the mass–metallicity relation does not rule out tidal mass-loss in Local Group satellites", Riley et al. This is Fig. 3: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Comparison of the RMS of GRACE data sets (a), the residual using ISBA-CTRIP (c) and the residual using WGHM 2.2d (d). The histograms of the RMS on all grid points (top), land (middle) and ocean (bottom) are shown in (b). The RMS reductions as a result of the difference between the RMS of GRACE data sets and the residuals derived from ISBA-CTRIP (e) and WGHM 2.2d (f). Blue areas indicate regions where residual RMS is lower than that of GRACE, while red areas indicate where it is higher. Average RMS and RMS_r values over land and ocean for each data set are indicated in the bottom corners of the respective maps.

Published in #GJI Geophysical Journal International: "Separating climate and deep Earth signals in satellite gravimetry: a global assessment", Saraswati et al. This is Fig. 1: please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Comparison of NIST (Y. Ralchenko & A. Kramida 2020) and Kurucz (R. L. Kurucz 2018) Fe I emission spectra at 3000 K and 6000 K; the 6000 K spectrum contains many lines only present in the Kurucz data set.

Published in #RASTI RAS Techniques & Instruments: "EXOATOM: a database of atomic spectra in ExoMol format", Ni et al. This is Fig. 2: please visit academic.oup.com/rasti/articl... to read the paper.

Is the Milky Way powered by dark matter rather than a black hole? 🤔⚫️

That's the suggestion in a new study published in our journal #MNRAS, which challenges the assumption that supermassive black hole Sagittarius A* is at the centre of our galaxy.

Read more 👉️ ras.ac.uk/news-and-pre...

Overview of the galaxy filament. Please see the paper for the full caption.

Published in MNRAS: "Unveiling a thin filament of the cosmic web in the Ursa Major supergroup", Xu et al. This is Fig. 1: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Seismicity near the Montney formation of northeastern British Columbia. All seismicity between 2000 and 2024 is shown in grey. Much of the seismicity has occurred in recent years in response to fluid injection operations. A spatiotemporal cluster of seismicity attributed to a specific injection operation is shown in yellow (Dokht et al. 2025). Results of the analysis of this cluster, assuming a stationary distribution, are shown in Fig. 6. A spatial cluster of seismicity attributed to multiple colocated injection operations is shown in purple (Visser et al. 2017, 2020). Results of the analysis of this cluster, assuming temporal variability of seismicity, are shown in Fig. 7. Seismic stations are shown as inverted triangles outlined in blue (for network code EO) and red (for other networks). The locations of the cities of Fort St. John (FSJ) and Dawson Creek (DC) are shown. The inset map illustrates the location of the study area (marked by the x) within Canadian geography. National political boundaries are shown as thick black lines. Thin black lines delineate provincial and territorial boundaries. The province of British Columbia (BC) is identified.

Published in #GJI Geophysical Journal International: "Robust probabilistic estimation of statistical variations in earthquake records: application to induced seismicity in western Canada", Gosselin et al. Please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social

Read Astronomy & Geophysics Vol. 66 Issue 6

🚀 Unlock the cosmos in Astronomy & Geophysics Vol. 66 Issue 6!

From gravitational waves to AI breakthroughs, submillimetre skies & more, don’t miss the Editor’s Choice's articles: oxford.ly/45AbToa

@rasjournals.bsky.social #Astronomy #Geophysics #SpaceScience

Comparison of synthetic and observed solar G-band intensity at wavelength 4306.8 ± 15 Å at different positions across the solar disc (different rows). The synthetic G band has been convolved with the SST photometric filter transmission function (M. Carlsson et al. 2004). The G-band observations were acquired with the Swedish 1-m Solar Telescope (SST; G. B. Scharmer et al. 2003a) on La Palma in 2003–2004 (T. E. Berger et al. 2004; Y. Lin et al. 2005; Van Der Voort private communication). For more detailed information on these observations we refer the reader to https://www.isf.astro.su.se/data1/gallery/. We show the disc centre µ = 1 at the bottom and two angles approaching the limb above. The black and white levels of the observations were adjusted to account for the different processing of the individual measurements.

Published in #MNRAS: "Solar carbon abundance from 3D non-LTE modelling of the diagnostic lines of the CH molecule", Hoppe et al. This is Fig. 2: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

The crustal (0-100 km depth) and interior structure of various seismic models published since the InSight mission. The representative models include Stahler AK model 74 (S. Stähler et al. 2021b), Stahler MD model 7 (S. Stähler et al. 2021b), Khan blue (A. Khan et al. 2021b), Khan red (A. Khan et al. 2021b), Duran model 190 (C. Durán et al. 2022a), Drilleau 1-D model 16 (M. Drilleau et al. 2024), Drilleau 3-D A model 60 (M. Drilleau et al. 2024), Drilleau 3-D B model 55 (M. Drilleau et al. 2024), Khan LSL model 793 (A. Khan et al. 2023a), Samuel LSL 47 (H. Samuel et al. 2023), Samuel 6 (H. Samuel et al. 2023).

Published in #GJI Geophysical Journal International: "On the detection of normal modes using InSight and their use in constraining Mars’ seismic structure", Hendrickx et al. This is Fig. 5: please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

The nebulæ and clusters of the Northern Heavens drawn upon an equal surface projection. The chart features a drawing of the Milky Way. The irresolvable nebulæ, now understood to be galaxies, are marked as black dots. Their distribution is rather inhomogeneous, exhibiting structures such as aggregations and filaments. The resolvable nebulæ are marked as red dots. Star clusters are marked with a red cross; they mostly adhere to the track of the Milky Way.

The nebulæ and clusters of the Southern Heavens drawn upon an equal surface projection. The chart features a drawing of the Milky Way. The irresolvable nebulæ, now understood to be galaxies, are marked as black dots. Their distribution is rather inhomogeneous, exhibiting structures such as aggregations and filaments. The Large and Small Magellanic Clouds stand out as extraordinary aggregations near the centre of the chart. The resolvable nebulæ are marked as red dots. Star clusters are marked with a red cross; they mostly adhere to the track of the Milky Way.

Cosmography archives

On Two Distribution Maps of the Nebulæ and Clusters in Dr. Dreyer's Catalogue of 1888.

by Sidney Waters (1894)

ui.adsabs.harvard.edu/abs/1894MNRA... 🔭🧪 @rasjournals.bsky.social

New Special Issue: Genesis and Evolution of Organics in Space

From spectroscopy to planetary exploration, researchers across India are working to uncover the chemical origins of life. Their contributions feature in the new MNRAS Special Issue Genesis & Evolution of Organics in Space.

🔗 oxford.ly/4alqpmg
@rasjournals.bsky.social

Final BH mass as a function of initial rotation, with initial helium core mass 160 Msolar for several values of the ^(12)C(alpha, gamma)^(16)O rate. The top panel shows results as a function of the initial stellar rotation in units of the critical value ; the bottom panel shows results as a function of the BH spin ⁠chi. Stars with faster rotation and smaller ^(12)C(alpha, gamma)^(16)O reaction rate undergo PISN and are not shown in the figure. The shaded contours indicate the 90 per cent credible intervals of the primary mass and spin in GW231123 (A. G. Abac et al. 2025). Please see the paper for more information.

Published in #MNRAS: "Can GW231123 have a stellar origin?", Croon et al. This is Fig. 1: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Sampling locations and morphological characteristics of Australasian tektites in South China. (a) Sampling locations for the studied tektites. Inserted image shows approximated geographic boundaries of the Australasian strewn field of tektite and microtektites (P. Yan et al. 2022), and the cyan shade marks the study area. Blue squares represent locations of studied Muong Nong-type tektites. Red circles represent locations of studied splash-form tektites. (b, c) Stratigraphic occurrence of Australasian tektites in South China. A sampled section shown in panel (a) is called Xuma Village that is located near the urban area of Leizhou City. The yellow arrow marks the position of the Australasian tektite sample (QB1-1). (d, e) Muong Nong-type tektites. (f, g) Splash-form tektites. (h) Orientation strategy for Muong Nong-type tektites. (i) Orientation strategy for splash-form tektites.

Published in #GJI Geophysical Journal International: "Palaeointensity of Australasian tektites from South China", Pan et al. This is Fig. 1: please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Reduced-order modelling of Cascadia’s slow slip cycles Summary. Slowslip events (SSEs) modulate the earthquake cycle in subduction zones, yet understanding their physics remains challenging due to sparse observ

New paper in press at GJI led by postdoc Yohai Magen (with Dave May and I): “Reduced-order modelling of Cascadia’s slow slip cycles” (doi.org/10.1093/gji/...).

Reduced-order models (ROMs) are fast surrogates of costly simulations. They compress the evolving, high-dimensional state of a ...

Gas density and velocity field of model P–G after 50, 1300, and 2600 orbits. Please see the paper for the full caption.

Published in #MNRAS: "Can photoevaporation open gaps in protoplanetary discs?", Weber et al. This is Fig. 2: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Seismicity at Aluto caldera from January 2012 to January 2014 used in the traveltime tomography. Events are colour-coded by depth, and seismic stations are indicated as grey triangles. Faults are indicated by solid black lines. The event distribution by longitude is displayed along the bottom axis, and the distribution by latitude is shown along the right axis. The majority of events at Aluto are shallow and are located at the centre of the caldera, and the seismic activity aligns parallel to the existing Artu Jawa Fault Zone (AJFZ).

Published in #GJI Geophysical Journal International: "Seismic tomography of Aluto volcano: insights into subsurface fluid distribution", Yemane et al. This is Fig. 1: please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Young star (age < 2 Gyr) mass map of Halo 23 at ⁠z = 0. The spiral arms identified by the algorithm (Section 2.2) are presented as purple pixels in the right panel.

Published in #MNRAS: "How mergers and flybys shape azimuthal age patterns in spiral galaxies", Chen et al. This is Fig. 1: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com

Geological settings and seismic station distribution. (a) Major geologic units of Mainland China; A solid rectangular box (red lines) outlines the study area; tectonic blocks are delineated by black lines modified from Zhang et al. (2003). (b) Distribution of seismic stations in the study area. Triangles (brown) represent seismic stations of ChinArray Phase III. Tectonic blocks are delineated by dashed lines modified from Zhao et al. (2005). The background is the crustal thickness from Wu et al. (2022). Abbreviations in the figures: OB, Ordos Block; DR, Daihai Rift; DTB, Datong Basin; HR, Hetao Rift; LFB, Linfen Basin; TYB, Taiyuan Basin; XMOB, Xingmeng Orogenic Belt; YOB, Yinshan Orogenic Belt. (c) Seismicity is downloaded from the USGS (https://earthquake.usgs.gov/earthquakes/search/) and denoted by dots.

Published in #GJI Geophysical Journal International: "High-resolution lithospheric Vs structure of the Ordos Block from dense-array ambient noise tomography: implications for reactivation", Liu et al. Please visit academic.oup.com/gji/article/... to read the paper. @royalastrosoc.bsky.social

Our journal RAS Techniques and Instruments (RASTI) has launched a new special issue entitled 'Habitable World Observatory Mission Concept Development Software, Tools, and Methodologies' – and is inviting submissions related to the topic.

Find out more at: academic.oup.com/rasti/pages/...

RASTI Student Prize: celebrating student research excellence

Student authors may be considered for the #RASTI Student Prize when submitting to RAS Techniques and Instruments.

Submit your research: oxford.ly/4qGkSwu
@rasjournals.bsky.social

Three-colour composite images of each of the 12 REBELS galaxies targeted in the Cycle 1 JWST program analysed in this work. Please see the paper for the full caption.

Published in #MNRAS: "REBELS-IFU: evidence for metal-rich massive galaxies at z ∼ 6−8", Rowland et al. This is Fig. 1: please visit academic.oup.com/mnras/articl... to read the paper. @royalastrosoc.bsky.social @academic.oup.com