Searcharxiv⌕ Search

arXiv · 2610.29127

Investigating a TeV-Halo Candidate around PSR J1928+1746 with HAWC

Abstract

We present an updated High-Altitude Water Cherenkov (HAWC) analysis of the crowded Galactic-plane area near PSR J1928+1746, which was previously linked to the extended source 3HWC J1928+178. With 2904 days of HAWC data, improved event reconstruction, and a multicomponent likelihood model that includes six TeV source components and Galactic diffuse emission, we describe the region using six components and find a distinct, moderately extended source close to PSR J1928+1746. This source, HAWC J1928+1750, is detected from about 2 TeV to above 100 TeV and is well-described by a log-parabola spectrum with normalization $K = 5.0 \times 10^{-15}$ TeV$^{-1}$ cm$^{-2}$ s$^{-1}$ at 12 TeV, index $α= 2.09$, curvature $β= 0.35$, and Gaussian extension $σ= 0.19^\circ$. Interpreting the emission using diffusion-halo templates under the assumption $B = 8 μ\mathrm{G}$ yields the diffusion coefficient D(100 TeV) = $2.1 \times 10^{27}$ cm$^2$ s$^{-1}$, which is about 500 times smaller than typical interstellar diffusion values at similar energies. This suggests that particle transport around PSR J1928+1746 is strongly suppressed under the TeV-halo interpretation. The TeV spectrum is consistent with leptonic inverse-Compton emission originating from pulsar-injected electrons and positrons, which requires less than approximately 1% of the pulsar's characteristic spin-down energy. However, a hadronic contribution from the surrounding environment cannot be excluded.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

The HAWC Collaboration, R. Alfaro, C. Alvarez, A. Andrés, E. Anita-Rangel, M. Araya, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, R. Babu, P. Bangale, A. Bernal, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, F. Carreón, S. Casanova, U. Cotti, J. Cotzomi, E. De la Fuente, P. Desiati, N. Di Lalla, R. Diaz Hernandez, M. A. DuVernois, J. C. Díaz-Vélez, K. Engel, T. Ergin, C. Espinoza, N. Fraija, S. Fraija, J. A. García-González, F. Garfias, N. Ghosh, S. Giri, M. M. González, J. A. González, J. A. Goodman, S. Groetsch, J. Gyeong, J. P. Harding, I. Herzog, D. Huang, F. Hueyotl-Zahuantitla, P. Hüntemeyer, A. Iriarte, S. Kaufmann, D. Kieda, R. Lake, K. Leavitt, H. León Vargas, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martínez-Castro, H. Martínez-Huerta, J. A. Matthews, P. Miranda-Romagnoli, P. E. Mirón-Enriquez, J. A. Morales-Soto, E. Moreno, M. Mostafá, M. Najafi, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, M. Osorio-Archila, N. Omodei, E. Ponce, Y. Pérez Araujo, E. G. Pérez-Pérez, S. Recchia, C. D. Rho, D. Rosa-González, M. Roth, A. Sandoval, M. Schneider, J. Serna-Franco, M. Shin, A. J. Smith, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, E. Varela, L. Villaseñor, X. Wang, Z. Wang, I. J. Watson, H. Wu, S. Yu, S. Yun-Cárcamo, X. Zhang, H. Zhou, C. de León. 2026-10-21. Investigating a TeV-Halo Candidate around PSR J1928+1746 with HAWC. https://arxiv.org/abs/2610.29127

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

A Possible Mass Ratio and Spin-Orbit Misalignment Correlation for Mergers of Binary Black Holes in Nuclear Star Clusters

Despite a decade's worth of gravitational wave observations, the origin of the binary black hole (BBH) mergers detected by the LIGO-Virgo-KAGRA (LVK) collaboration remains an open question. Towards assessing the feasibility and prevalence of the many proposed BBH formation channels, the spin properties of the merging black holes (BHs) hold significant promise, particularly their orientations. Moderate preferential alignment of BH spins with their orbit normals, as well as an apparent anti-correlation between the BBH effective spin parameters $χ_{\rm eff}$ and their mass ratios, would appear to disfavor purely dynamical BBH formation mechanisms, as they lack a preferred orientation to the system. However, alternatives are filled with physical and modeling uncertainties. In this paper, we highlight a dynamical route to easily characterizable spin evolution that results in analytically predictable spin distributions. We show that, when a stellar binary forms a BBH through two phases of stable mass transfer, and the BBH is subsequently driven to merger by the gravitational perturbation of a distant massive object (such as a supermassive black hole), the resulting $χ_{\rm eff}$ may be anti-correlated with the binary mass ratio. While the mechanism as proposed only operates in a modest region of parameter space, it also predicts significantly tighter correlations than are seen in the GWTC-4.0 systems. We discuss avenues for future work that may significantly expand the parameter space of our mechanism while still remaining broadly consistent with observations.

astro-ph.HE↗

TDEs on FIRE: Illuminating the Cosmic Evolution of Tidal Disruption Rates

Tidal disruption events have been extensively studied in the local universe, but their prevalence at high redshifts remains largely unexplored. Using the FIRE-2 cosmological zoom-in simulations, we compute the per-galaxy tidal disruption rate (TDR) over $z=1-10$, covering black holes from IMBHs to SMBHs. The averaged TDR rises from the early universe, peaks at $\sim 4 \times 10^{-4} \, \text{gal}^{-1} \text{yr}^{-1}$ near $z \sim 2.5$, and declines to $\sim 10^{-5} \, \text{gal}^{-1} \text{yr}^{-1}$ at $z=1$. The TDR correlates strongly with host galaxy star formation rate and central stellar density at all redshifts. Qualitatively, the TDR trends with the $M_{\rm BH}$ and $M_{\rm gal}$ persist from high redshift to the local universe, suggesting similar BH-galaxy scaling across cosmic time. Satellite galaxies exhibit comparably high TDRs, with their fractional contribution increasing significantly at high redshifts, highlighting their potential for probing IMBHs and early galaxy assembly. This work demonstrates that cosmological simulations offer a promising avenue for constraining the cosmic evolution of the TDR, paving the way for future comparisons with next-generation observations.

astro-ph.HE↗

Observable Signatures of Supernova Shock Breakout in Confined Circumstellar Medium

Supernova shock breakout encodes rich information about stellar explosions, including the properties of the progenitor, the explosion mechanism, and the circumstellar environment. We present the first two-dimensional multigroup radiation-hydrodynamic simulations of shock breakout from Red Supergiant (RSG) progenitor stars embedded in confined circumstellar medium (CSM) produced shortly before core collapse. Our simulations reveal that radiation escaping ahead of the shock forms a radiative precursor that modifies the shock dynamics, drives multidimensional mixing within the radiating gas layers, and alters the emergent radiation from the CSM. For the CSM models explored here, the resulting bolometric light curves reach peak luminosities of ${\sim}1\text{-}3 \times 10^{44}\ \mathrm{erg\ s^{-1}}$ with durations of ${\sim}4\text{-}35$~hr, with these signatures controlled by the CSM mass and the confined radius. Our multi-wavelength calculations further reveal a pronounced extreme-ultraviolet emission, where ionizing photons of energies ${\ge}54.4$~eV can sustain flash-ionized He II and power strong emission from its recombination line of $λ4686\ \mathring{A}$. Furthermore, we identify diagnostic signatures of shock breakout with dense CSM and assess their detectability with Einstein Probe and ULTRASAT. Our models and predictions provide promising diagnostics of shock breakout in CSM that may be detectable by current and forthcoming high-cadence ultraviolet and X-ray space telescopes.

astro-ph.HE↗