You are browsing the site archives for June 2025.
Missions to Mars with the Starship Could Only Take Three Months In a recent paper, UCSB physicist Jack Kingdom identified a trajectory for a rapid transit (90 days) to Mars using SpaceX’s Starship. This proposal offers an alternative to mission architectures that rely on nuclear propulsion to reduce transit times. Universe Today Go to SourceRead More →
The CME did not disappoint! More storming activity to come? We remain at geomagnetic storm conditions as the effects of the coronal mass ejection from an M8 solar flare continue to influence our planet. The coronal mass ejection arrival earlier than expected, yesterday around 05:30 UTC. The north-south direction of the IMF (Bz) has been prolonged southward during the onset of the storm which resulted in G3 and G4 geomagnetic storm conditions. This triggered amazing aurora displays which were visible from southern parts of Australia, New Zealand and even places like Utah in the USA. Space Weather Live Go to SourceRead More →
M8.2 solar flare, Strong G4 geomagnetic storm watch Wow! Major solar fireworks today. Charge your camera batteries and put on your finest jacket for tomorrow night as strong (G3) or perhaps even severe (G4) geomagnetic storm conditions are possible tomorrow evening (1 June) into 2 June. The center of attention today was sunspot region 4100 which produced a gorgeous long duration M8.2 solar flare today (R2-moderate) peaking at 00:05 UTC. This region is close to the center of the Earth-facing solar disk and launched a major asymmetrical full halo (as seen by SOHO/LASCO) coronal mass ejection in space with a pretty much guaranteed earth-directed component.Read More →
Another X-flare! Potent sunspot region 4087! Wow! We go from a period with hardly any solar activity worth mentioning to two X-class solar flares in two days! Space Weather Live Go to SourceRead More →
X1.1 solar flare from sunspot region 4086 Solar activity has been relatively quiet for weeks now but that came to an abrupt end today as departing sunspot region 4086 which is now close to the west limb produced an X1.1 solar flare (R3-strong radio blackout) that peaked at 15:37 UTC. Space Weather Live Go to SourceRead More →
CME arrival, G3 storm watch A coronal mass ejection has arrived at our planet. This is the first of possibly two coronal mass ejections that were expected to arrive from filament eruptions on April 12 and 13. The minor G1 geomagnetic storm threshold has already been reached and the NOAA SWPC has a strong G3 geomagnetic storm watch in place for tomorrow, 16 April. Keep an eye on the data here on this website in the hours ahead. There is more action to come! Space Weather Live Go to SourceRead More →
pySTARBURST99: The Next Generation of STARBURST99 Calum Hawcroft, Claus Leitherer, Oskar Arangure, John Chisholm, Sylvia Ekstrom, Sebastien Martinet, Lucimara Martins, Georges Meynet, Christophe Morisset, Andreas Sander, Aida Wofford arXiv:2505.24841v1 Announce Type: new Abstract: STARBURST99 is a population synthesis code tailored to predict the integrated properties or observational characteristics of star-forming galaxies. Here we present an update to STARBURST99 where we port the code to python, include new evolutionary tracks both rotating and non-rotating at a range of low metallicity environments. We complement these tracks with a corresponding grid of new synthetic SEDs. Additionally we include both evolutionary and spectral models of stars up to 300-500Msol.Read More →
Electron Penetration Acceleration in Turbulent Magnetic Loops Zheng Gong, Sida Cao, Caleb Redshaw, Matthew R. Edwards arXiv:2504.03116v2 Announce Type: replace-cross Abstract: Using particle-in-cell simulations to study fast radio burst (FRB) propagation in a tenuous plasma, we identified a novel mechanism that occurs during the growth of turbulent magnetic loops: electron penetration acceleration. The loops have an electromagnetic left-hand chirality distinct from that of well-known quasistatic magnetic islands. The fast electrons penetrate through the loops and thus are accelerated to unexpected relativistic energies due to the symmetry breaking induced by the coupling between the loop field and the non-relativistic electromagnetic wave. The identified features of penetrationRead More →
Identification of New Candidate Be/X-Ray Binary Systems in the Small Magellanic Cloud via Analysis of S-CUBED Source Catalog Thomas M. Gaudin, Jamie A. Kennea, Malcolm J. Coe, Phil A. Evans arXiv:2505.24766v1 Announce Type: new Abstract: It has long been known that a large population of Be/X-ray Binaries (BeXRBs) exists in the Milky Way’s neighboring dwarf galaxy, the Small Magellanic Cloud (SMC), due to a recent period of intense star formation. Since 2016, efforts have been made to monitor this population and identify new BeXRBs through the Swift SMC Survey (S-CUBED). S-CUBED’s weekly observation cadence has identified many new BeXRBs that exist within the SMC, butRead More →
Sunrise III: Overview of Observatory and Instruments Andreas Korpi-Lagg, Achim Gandorfer, Sami K. Solanki, Jose Carlos del Toro Iniesta, Yukio Katsukawa, Pietro Bernasconi, Thomas Berkefeld, Alex Feller, Tino L. Riethm"uller, Alberto ‘Alvarez-Herrero, Masahito Kubo, Valent’in Mart’inez Pillet, H. N. Smitha, David Orozco Su’arez, Bianca Grauf, Michael Carpenter, Alexander Bell, Mar’ia-Teresa ‘Alvarez-Alonso, Daniel ‘Alvarez Garc’ia, Beatriz Aparicio del Moral, Daniel Ayoub, Francisco Javier Bail’en, Eduardo Bail’on Mart’inez, Maria Balaguer Jim’enez, Peter Barthol, Montserrat Bayon Laguna, Luis R. Bellot Rubio, Melani Bergmann, Julian Blanco Rodr’iguez, Jan Bochmann, Juan Manuel Borrero, Antonio Campos-Jara, Juan Sebasti’an Castellanos Dur’an, Mar’ia Cebollero, Aitor Conde Rodr’iguez, Werner Deutsch, Harry Eaton, Ana BelenRead More →
SHELLQs. Bridging the gap: JWST unveils obscured quasars in the most luminous galaxies at z > 6 Yoshiki Matsuoka, Masafusa Onoue, Kazushi Iwasawa, Kentaro Aoki, Michael A. Strauss, John D. Silverman, Xuheng Ding, Camryn L. Phillips, Masayuki Akiyama, Junya Arita, Masatoshi Imanishi, Takuma Izumi, Nobunari Kashikawa, Toshihiro Kawaguchi, Satoshi Kikuta, Kotaro Kohno, Chien-Hsiu Lee, Tohru Nagao, Ayumi Takahashi, Yoshiki Toba arXiv:2505.04825v2 Announce Type: replace Abstract: The unprecedented sensitivity of the James Webb Space Telescope (JWST) has uncovered a surprisingly abundant population of mildly obscured, low-luminosity active galactic nuclei (AGNs) in the epoch of reionization (EoR). However, the link between these objects and classical unobscured quasarsRead More →
Likelihoods for Stochastic Gravitational Wave Background Data Analysis Gabriele Franciolini, Mauro Pieroni, Angelo Ricciardone, Joseph D. Romano arXiv:2505.24695v1 Announce Type: cross Abstract: We present a systematic study of likelihood functions used for Stochastic Gravitational Wave Background (SGWB) searches. By dividing the data into many short segments, one customarily takes advantage of the Central Limit Theorem to justify a Gaussian crosscorrelation likelihood. We show, with a hierarchy of ever more realistic examples, beginning with a single frequency bin and one detector, and then moving to two and three detectors with white and colored signal and noise, that approximating the exact Whittle likelihood by various Gaussian alternativesRead More →
The Tracking Tapered Gridded Estimator for the 21-cm power spectrum from MWA drift scan observations II: The Missing Frequency Channels Khandakar Md Asif Elahi, Somnath Bharadwaj, Suman Chatterjee, Shouvik Sarkar, Samir Choudhuri, Shiv Sethi, Akash Kumar Patwa arXiv:2410.11380v2 Announce Type: replace Abstract: Missing frequency channels pose a problem for estimating $P(k_perp,k_parallel)$ the redshifted 21-cm power spectrum (PS) from radio-interferometric visibility data. This is particularly severe for the Murchison Widefield Array (MWA), which has a periodic pattern of missing channels that introduce spikes along $k_parallel$. The Tracking Tapered Gridded Estimator (TTGE) overcomes this by first correlating the visibilities in the frequency domain to estimate the multi-frequencyRead More →
Bridging Unstratified and Stratified Simulations of the Streaming Instability for $tau_s=0.1$ Grains Jeonghoon Lim, Stanley A. Baronett, Jacob B. Simon, Chao-Chin Yang, Debanjan Sengupta, Orkan M. Umurhan, Wladimir Lyra arXiv:2505.23902v1 Announce Type: new Abstract: The streaming instability (SI), driven by aerodynamic coupling between solids and the gas under a global radial pressure gradient, concentrates solids and facilitates planetesimal formation. Unstratified simulations are commonly used to study the SI, based on the assumption that they approximate conditions near the disk midplane. However, it remains unclear how accurately these unstratified simulations capture the midplane dust-gas dynamics in stratified disks. To address this, we examine the saturated stateRead More →
Cosmology with Topological Deep Learning Jun-Young Lee, Francisco Villaescusa-Navarro arXiv:2505.23904v1 Announce Type: new Abstract: The standard cosmological model with cold dark matter posits a hierarchical formation of structures. We introduce topological neural networks (TNNs), implemented as message-passing neural networks on higher-order structures, to effectively capture the topological information inherent in these hierarchies that traditional graph neural networks (GNNs) fail to account for. Our approach not only considers the vertices and edges that comprise a graph but also extends to higher-order cells such as tetrahedra, clusters, and hyperedges. This enables message-passing between these heterogeneous structures within a combinatorial complex. Furthermore, our TNNs are designed to conserveRead More →
Hydrodynamic simulations of black hole evolution in AGN discs II: inclination damping for partially embedded satellites Henry Whitehead, Connar Rowan, Bence Kocsis arXiv:2505.23899v1 Announce Type: new Abstract: We investigate the evolution of black holes on orbits with small inclinations ($i 3H_0R_0^{-1}$, damping efficiency decreases for higher inclinations. We consider a variety of different AGN environments, finding that damping is stronger for systems with a higher ambient Hill mass: the initial gas mass within the BH sphere-of-influence. We provide a fitting formula for the inclination changes as a function of Hill mass. We find reasonable agreement between the damping driven by gas gravity in the simulationsRead More →
Superfluid Dark Matter Lasha Berezhiani, Giordano Cintia, Valerio De Luca, Justin Khoury arXiv:2505.23900v1 Announce Type: new Abstract: The superfluid dark matter model offers an elegant solution to reconcile discrepancies between the predictions of the cold dark matter paradigm and observations on galactic scales. In this scenario, dark matter is composed of ultralight bosons with self-interactions that can undergo a superfluid phase transition in galactic environments. In this review, we explore the theoretical foundations of dark matter superfluidity, detailing the conditions required for the formation and stability of superfluid cores of astrophysical size. We examine the phenomenological consequences for galactic dynamics, including the impact on galaxyRead More →
The Density Distribution of Compressively-Forced Supersonic Turbulence Depends on the Driving Correlation Time Philipp Grete, Evan Scannapieco, Marcus Br"uggen, Liubin Pan arXiv:2505.23898v1 Announce Type: new Abstract: Supersonic turbulence plays a critical role in shaping astrophysical systems, from molecular clouds to the circumgalactic medium. Key properties of this turbulence include the Mach number, driving scale, and nature of the driving mechanism, which can be solenoidal (divergence-free), compressive (curl-free), or a mix of the two. A less studied property is the correlation time of the driving accelerations, $tau_{rm a}.$ While this timescale has a minimal impact on solenoidally-driven turbulence, we show that it has a strong impactRead More →
Estimating Global Ejecta Mass Ratios in Tycho’s SNR Tyler Holland-Ashford, Patrick Slane, Brian Williams arXiv:2505.23897v1 Announce Type: new Abstract: In this work, as a follow-up to our similar analysis of Kepler’s supernova remnant (SNR), we estimate total mass ratios of various ejecta elements in Tycho’s SNR using Suzaku X-ray data. In our spectral analysis, we account for uncertainties arising from Suzaku’s effective area calibration (5%-15%) and from the unknown filling factors of the various plasma components in our spectral model (1%-10%). We compare our calculated ejecta mass ratios to results from previous X-ray analyses of Tycho’s SNR and to the nucleosynthesis results from Type IaRead More →
Excess of substructure due to primordial black holes Patricio Colazo, Nelson Padilla, Federico Stasyszyn arXiv:2505.23896v1 Announce Type: new Abstract: This paper explores the impact of primordial black holes (PBHs) on the abundance of low-mass haloes and subhaloes in the dark and low-stellar-mass regime, and examines how these effects can be measured through fluctuations in strong lensing and brightness fluctuations in clusters of galaxies, providing potential ways to constrain the fraction of dark matter in PBHs. Various dark matter candidates leave unique imprints on the low-mass range of the halo mass function, which can be challenging to detect. Among these are hot and warm dark matterRead More →
