Quantum-gravitational mechanism could explain the universe’s homogeneity Our universe is known to be remarkably homogeneous and isotropic. This essentially means that matter is distributed evenly throughout the universe and that it looks almost the same in all directions. phys.org Go to SourceRead More →
Watching Dawn and Dusk on a Distant Hot Jupiter Astronomers using the James Webb Space Telescope have caught an extreme, tidally locked exoplanet in the act of showing two very different faces at once, a fierce, wind battered hemisphere and a comparatively gentler half. The discovery not only reveals a planet with a genuine weather system violent enough to tear water apart, it hints at a missing ingredient in how scientists model alien atmospheres altogether. Universe Today Go to SourceRead More →
Listening for the Universe’s Faintest Whispers, a Billion Supernovae at Once Buried a kilometre underground in Japan, one of the world’s most sensitive detectors may have caught its first faint trace of a sound scientists have been straining to hear for decades, the combined whisper of every supernova that has ever exploded across the universe. It is not yet a confirmed discovery, but if it holds up, it could rewrite how we trace the life and death of stars. Universe Today Go to SourceRead More →
Indication for Decreasing Dispersion Measure in the Population of Repeating Fast Radio Bursts and Connection to Young Supernova Remnant Expansion Xiang-han Cui, Cheng-min Zhang, Di Li, Pei Wang, Erbil G"ugercinou{g}lu, Joeri van Leeuwen, Yi-dan Wang, Chao-wei Tsai, Xiang-lei Chen, Wen-qi Ma, Habtamu Menberu Tedila arXiv:2606.23903v2 Announce Type: replace Abstract: Fast Radio Bursts (FRBs) are millisecond-duration, highly energetic radio transients of uncertain origin. Repeating FRBs provide an excellent population for investigating their nature, particularly through studies of parameter evolution. Out of the 63 repeaters monitored by CHIME, we select the 19 sources with more than ten detected bursts, and examine their long-term dispersion measure (DM) evolution.Read More →
A cooler look at the environment of Cygnus X-1: Searching for dynamical interactions within cold molecular gas Pau Bosch-Cabot, Alexandra J. Tetarenko, Valent’i Bosch-Ramon, James C. A. Miller-Jones, David M. Russell, Sara E. Motta, Pikky Atri, Mar’ia D’iaz-Trigo, Isabella Mariani, Steve Prabu arXiv:2607.08994v1 Announce Type: new Abstract: We present IRAM–30m observations aimed at identifying potential outflow-interstellar medium interaction sites in the vicinity of the black hole X-ray binary Cygnus X–1, which displays persistent relativistic jets and a prominent stellar wind. Using this dataset, we construct molecular line emission maps, identifying a never before seen molecular structure potentially linked to X-ray binary-driven feedback. This structure, surroundingRead More →
How to count clustered galaxies Yunting Wang, Ryley Hill, Douglas Scott, Tessa Vernstrom arXiv:2605.09248v2 Announce Type: replace Abstract: Obtaining robust galaxy number counts is crucial for understanding galaxy evolution, and submillimetre counts in particular have proven valuable for revising subgrid physics models in cosmological simulations. In confusion-limited surveys, which are common at these wavelengths, statistical methods such as $P(D)$ fluctuation analysis are required to recover counts of faint, unresolved galaxies. However, the standard $P(D)$ framework assumes that galaxies are Poisson-distributed, whereas in reality galaxies are clustered. Using simulations, we demonstrate that this clustering systematically biases $P(D)$-derived number counts, and present an empirical method that simultaneouslyRead More →
Star Clusters in the Ultraviolet Annapurni Subramaniam, Samyaday Choudhury, Richard de Grijs, Vikrant V. Jadhav, Chengyuan Li, Snehalata Sahu, Kaushar Vaidya, Li Wang arXiv:2607.08917v1 Announce Type: new Abstract: Ultraviolet (UV) observations provide a powerful window into the hot and evolved stellar populations that shape the structure, evolution and integrated light of star clusters. Because UV wavelengths are highly sensitive to massive main-sequence stars, blue straggler stars (BSS), extreme-horizontal branch (HB) stars, post-HB stars, interacting binaries and compact remnants, they probe key evolutionary processes that are inaccessible at optical and infrared wavelengths. This review synthesises five decades of UV studies of star clusters across the MilkyRead More →
Magnetic field generation in mergers of massive main-sequence stars Sebastian T. Ohlmann, Fabian R. N. Schneider, Friedrich K. Roepke, Ruediger Pakmor, Philipp Podsiadlowski, Volker Springel arXiv:2512.13424v3 Announce Type: replace Abstract: Magnetic fields are found in many astrophysical objects, ranging from galaxy clusters to the interstellar medium of galaxies and neutron stars. Strong surface magnetic fields are also observed in about 7% of OBA-type stars, and stellar mergers are the likely origin of at least some of them. We investigated magnetic-field amplification during the merger of a 9 and an 8 $M_odot$ main-sequence star using 3D magnetohydrodynamic simulations from our previous work. We focused on theRead More →
Tentative detection of circularly polarized bursty radio emissions from the HD 189733 exoplanetary system using NenuFAR beamformed observations Jake D. Turner, Philippe Zarka, Jean-Mathias Grie{ss}meier, Corentin K. Louis, Xiang Zhang, Emilie Mauduit, Tomoki Kimura arXiv:2607.08910v1 Announce Type: new Abstract: Observing auroral radio emission is one of the most promising methods for detecting exoplanetary magnetic fields, which provide valuable insights into planetary interiors, atmospheric properties, and potential habitability. The first hints of exoplanet auroral emission are starting to emerge. Recently, Zhang et al. (2025) reported a detection at 50 MHz of a circularly polarized bursty emission from the HD 189733 exoplanetary system using NenuFAR low-frequency imagingRead More →
Periodic line-of-sight velocity-driven modulations to gravitational waves emitted by compact binaries in Keplerian outer orbits Avinash Tiwari, Shasvath J. Kapadia, Aditya Vijaykumar, Sourav Chatterjee arXiv:2607.09644v1 Announce Type: cross Abstract: The centre of mass (CoM) of compact binary coalescences (CBCs) occurring in the vicinity of a supermassive black hole, through interaction with an arbitrary third body (e.g., of stellar mass), or in a dense stellar environment, will undergo a time-varying line-of-sight (LOS) velocity. This in turn leads to a time-varying Doppler shift and corresponding modulations in the shape of the gravitational waves (GWs). The phase and amplitude corrections arising from constant LOS acceleration and its higher-orderRead More →
Chromatic Effects Across the Roman Focal Plane: Implications for Supernova Photometry and Measurements of Cosmological Parameters Rujuta Purohit, Dillon Brout, Daniel Scolnic, Richard Kessler, Jillian Paulin, Stefano Casertano, Nora F. Sherman, Rebekah Hounsell, Eric R. Switzer, Benjamin M. Rose, Masao Sako, Lauren Aldoroty, Kene Anumba, Maria Acevedo, David Rubin, Russell E. Ryan Jr., The Roman Supernova Cosmology Project Infrastructure Team arXiv:2607.08886v1 Announce Type: new Abstract: Calibration uncertainties are the leading systematics in cosmological analyses using Type Ia supernovae (SNe Ia). For the textit{Nancy Grace Roman Space Telescope (Roman)}, we quantify the impact of chromatic effects on SNe Ia photometry and derived cosmological parameters, using simulatedRead More →
In-medium hyperon potentials and the quarkyonic hyperon onset: charged $Sigma$’s in $beta$-equilibrium and the neutrino connection Jaroslaw Nowak arXiv:2607.09280v1 Announce Type: cross Abstract: Quarkyonic matter resolves the neutron-star hyperon puzzle statistically: neutrons fill low-momentum $d$-quark phase space, shifting the $S=-1$ threshold from $muB=M_Y$ to $2M_Y-M_N$ and suppressing residual softening by $1/Nc^3$ in the Fujimoto–Kojo–McLerran (FKM) mechanism. We dress FKM’s IdylliQ model with in-medium potentials, constrained by hypernuclear data and neutrino-induced hyperon FSI, and find: (i) the dressed onset, $muB^{rm onset}=(2M_Y{-}M_N)+2U_Y-UN$, carries $U_Y$ at weight 2, with $dn_{rm onset}/dU_Ysimeq0.3,nz$ per $10MeV$, twice the leverage. (ii) A self-consistent neutron potential enters at weight $-2$, so protection needsRead More →
Studying the Variable Continuum and Emission Line Spectrum of 4U 1700-377 using NuSTAR’s Stray Light Colin J Bourque, McKinley C Brumback, Brian W Grefenstette, Douglas J K Buisson, Renee M Ludlam, Guglielmo Mastroserio, Steven Rossland arXiv:2607.08876v1 Announce Type: new Abstract: The high-mass X-ray binary 4U 1700-377 shows strong variation in brightness on timescales of hundreds of seconds due to accretion from a highly clumped stellar wind from the companion. Using two focused observations and five stray light observations from NuSTAR, we are able to expand the baseline of observations of the source and track spectral parameters throughout the source’s variability. The focused NuSTAR observations confidentlyRead More →
Tunable responsivity and bandwidth in microwave kinetic inductance detectors via readout current nonlinearity Maclean Rouble, Peter Day, Matt Dobbs, Joshua Montgomery, Sofiia Savchyn, Graeme Smecher arXiv:2607.09178v1 Announce Type: cross Abstract: Microwave kinetic inductance detectors (MKIDs) are generally read out with microwave readout tones of high enough amplitude to adequately suppress the noise contribution of the first-stage amplifier. At high readout power, the detector’s resonant frequency is altered as a result of the dependence of the kinetic inductance on the internally circulating microwave current. With the tone placed below the resonant frequency, the nonlinear frequency shift results in a positive feedback effect that can significantly enhanceRead More →
Observations of the Halo Star HD 177566 William V. Dixon, Pierre Chayer arXiv:2607.08858v1 Announce Type: new Abstract: We have analyzed archival FUV and optical spectra of the hot halo star HD 177566. The star has an effective temperature $T_{rm eff} = 33{,}000 pm 1000$ K, surface gravity $log g = 3.79 pm 0.11$, and helium abundance $log N({rm He})/N({rm H}) = -0.86 pm 0.05$. Abundances of 13 additional elements are consistent with those of other halo stars, save for carbon, which is underabundant by about 1 dex. The low-order hydrogen Balmer lines are not well reproduced by our models. The diffuse lines of He IRead More →
Spatial decomposition of Little Red Dots with JWST/NIRSpec IFU into broad-line red cores and narrow-line blue host galaxies Yuzo Ishikawa, Anna-Christina Eilers, Rohan P. Naidu, Jorryt Matthee, Rongmon Bordoloi, John Chisholm, Jenny E. Greene, Yilun Ma, Pascal A. Oesch, Wendy Q. Sun, Alberto Torralba, John R. Weaver, Stijn Wuyts, Mengyuan Xiao arXiv:2607.09647v1 Announce Type: new Abstract: Little Red Dots (LRDs) are a population of compact red sources discovered by the James Webb Space Telescope (JWST). Imaging and spectroscopy have shown that LRDs exhibit a complex spectrum with a “V-shaped” continuum, broad Balmer emission lines, and in some cases Balmer absorption. While the physical origin ofRead More →
WST — Wide-field Spectroscopic Telescope: The Next Leap in Wide-field Spectroscopy Roland Bacon, Olga Bellido, Philippe Dierickx, Paolo Franzetti, Roelof S. de Jong, David Lee, Vincenzo Mainieri, Sofia Randich, Richard I. Anderson, Francesco Belfiore, Henri Boffin, Julia Bryant, Kjetil Dohlen, Richard Ellis, Gaston Gausachs, Alexandre Jeanneau, Laura Magrini, Simon O’Toole, Michele Moresco, Arlette P’econtal, Anna Puglisi, Paula S’anchez S’aez, Rodolfo Smiljanic, Stefano Zibetti, Bodo Ziegler, Matthew Colless, Matt Lehnert, Pietro Schipani, Laurence Tresse, Joe Barrow, Nicolas Bouch’e, Dimitri Buffat, Vincenzo De Caprio, Letizia P. Cassar`a, Younes Chadid, Corentin Cudennec, Bianca De Caro, Simone D’Auria, Laurane Fr’eour, Marco Fumana, Maria Cristina Fortuna, Adriana Gargiulo, Pascale Hibon,Read More →
Binary stars as dynamical tracers in globular clusters .II. Evolution of the radial distribution of the binary star fraction J. Bruce, E. Vesperini, E. Dalessandro, M. Cadelano, F. R. Ferraro, B. Lanzoni, G. Beccari, C. Giusti arXiv:2607.08836v1 Announce Type: new Abstract: The distinct dynamical environments occupied by multiple stellar populations in globular clusters play a significant role in many aspects of cluster evolution, including the dynamics of binary stars. Recent observational analyses of Galactic globular clusters have revealed a bimodal radial trend in the binary fraction: the fraction of binaries is enhanced in both the central and outer regions of clusters, with a noticeable minimumRead More →
The contribution of stars, dust, neutral gas and supermassive black holes in galaxies to the cosmic baryon inventory Jordan C. J. D’Silva, Simon P. Driver, Aaron S. G. Robotham, Andrew Battisti, Elisabete da Cunha, Luke J. M. Davies, Stephen Eales, Claudia del P. Lagos arXiv:2601.08112v3 Announce Type: replace Abstract: We compute the cosmic stellar, dust and neutral gas mass history at $0arXiv:2601.08112v3 Announce Type: replace Abstract: We compute the cosmic stellar, dust and neutral gas mass history at $0Read More →
Hybrid Simulations of Proton Acceleration at Oblique High-$beta$ Shocks Yevhen Kylivnyk, Damiano Caprioli, Luca Orusa arXiv:2607.08835v1 Announce Type: new Abstract: Collisionless shocks in the intracluster and intergalactic medium (ICM/IGM) are expected to energize both electrons and ions. While electron acceleration is revealed by prominent radio emission, $gamma$-ray emission from hadronic interactions remains undetected, suggesting that high-$beta$ (ratio of thermal to magnetic pressure), low-Mach-number shocks cannot accelerate protons efficiently. We present three-dimensional hybrid simulations, in which ions are treated kinetically and electrons as a fluid, of quasi-perpendicular (magnetic obliquity $vartheta = 80^circ$) shocks with sonic Mach numbers $M_s sim 3{-}15$ and plasma $beta gtrsim 15$, representativeRead More →
