Unveiling the Hidden Radiation: The Persistent Emission of PSR B0823+26 in Its Quiescent State

Abstract In this study, we report on a detailed polarimetric single-pulse analysis of the radio emission from the pulsar B0823+26 (J0825+2637) during its quiescent state. Using the unprecedentedly high-sensitive observations carried out with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) at 1250 MHz, potentially interesting emission features are revealed, distinct from bright-state characteristics. The interpulse emission is completely absent, with only the main pulse and postcursor components detected. Notably, no bridging emission is observed between these two distinct emission components. Both the main pulse and postcursor exhibit continuous emission without any pulse nulling phenomenon throughout the observation period. During the nearly 3 hr continuous observation period, a total of 571 bright pulses with relative pulse energy larger than 10 are detected within the main pulse window. Their energy distribution follows a power-law distribution with an index of −2.39 ± 0.03. The interburst time distribution is consistent with a stationary Poisson process, yielding a burst rate of 158 ± 8 events per hour. Furthermore, the fluctuation spectral analysis of single pulse behavior reveals the existence of a periodic amplitude modulation of longitude-stationary subpulses with a periodicity of 20 ± 7 rotational periods across the main pulse window. Possible emission mechanisms are discussed.