6 papers

astro-ph.SR2026

SN 2021pfs: A Type Ia Supernova Likely Affected by Progenitor Metallicity, as Revealed by Comparison with Its Twin Counterpart

Abdusamatjan Iskandar, Xiaofeng Wang, Ali Esamdin +15

We present extensive photometric and spectroscopic observations of the normal type Ia supernovae (SNe Ia) 2021pfs, which occurred in the Seyfert 2 galaxy NGC 5427 at a redshift 0.0…

astro-ph.HE2026

A broadband outburst of the compact steep-spectrum quasar 3C 138 in 2024-2026

T. V. Mufakharov, Yu. V. Sotnikova, V. V. Vlasyuk +20

After several decades of relative quiescence, the compact steep-spectrum quasar 3C 138 entered an active phase in 2024-2026, exhibiting strong broadband flaring. We investigate its…

astro-ph.SR2026

Investigating the electron temperature of [Ar IV] in planetary nebulae using the DESIRED database

J. García-Rojas, E. Reyes-Rodríguez, J. E. Méndez-Delgado +9

(Abridged) We investigate the behaviour of the electron temperature derived from [Ar IV] lines, Te([Ar IV]), in a sample of PNe to characterize the thermal structure of high-excita…

astro-ph.SR2026

Double-periodic pulsations simultaneously detected in mid-infrared and hard X-ray emissions during an X1.5 flare

Dong Li, Yuyang Ye, Xianyong Bai +1

Quasi-periodic pulsations (QPPs) have been observed in a broad electromagnetic spectrum, encompassing radio, ultraviolet, white light, X-rays, and Gama-rays. Yet, flare-associated…

astro-ph.GA2026

A new model of quasar mass evolution

Z. Li, M. Zhang, Q. -H. Peng +1

Magnetic monopoles have been a trending topic among physicists and astronomers since the 1930s. Researchers have been working hard to find evidence of magnetic monopoles in laborat…

astro-ph.HE2026

Multiwavelength variability of the high-energy neutrino candidate PKS 0735+178 over three decades

T. Mufakharov, Yu. Sotnikova, V. Vlasyuk +12

We present the multiwavelength variability of the BL Lac object PKS 0735+178, associated with the high-energy neutrino event IC211208A. The light curves cover the radio (1-230 GHz)…