CHIME Discovery of a Binary Pulsar with a Massive Non-Degenerate Companion

Autor: Andersen, Bridget C., Fonseca, Emmanuel, McKee, J. W., Meyers, B. W., Luo, Jing, Tan, C. M., Stairs, I. H., Kaspi, Victoria M., van Kerkwijk, M. H., Bhardwaj, Mohit, Boyle, P. J., Crowter, Kathryn, Demorest, Paul B., Dong, Fengqui A., Good, Deborah C., Kaczmarek, Jane F., Leung, Calvin, Masui, Kiyoshi W., Naidu, Arun, Ng, Cherry, Patel, Chitrang, Pearlman, Aaron B., Pleunis, Ziggy, Rafiei-Ravandi, Masoud, Rahman, Mubdi, Ransom, Scott M., Smith, Kendrick M., Tendulkar, Shriharsh P.
Rok vydání: 2022
Předmět:
Zdroj: ApJ 943 57 (2023)
Druh dokumentu: Working Paper
DOI: 10.3847/1538-4357/aca485
Popis: Of the more than $3{,}000$ radio pulsars currently known, only ${\sim}300$ are in binary systems, and only five of these consist of young pulsars with massive non-degenerate companions. We present the discovery and initial timing, accomplished using the Canadian Hydrogen Intensity Mapping Experiment telescope (CHIME), of the sixth such binary pulsar, PSR J2108+4516, a $0.577$-s radio pulsar in a 269-day orbit of eccentricity 0.09 with a companion of minimum mass $11$ M$_{\odot}$. Notably, the pulsar undergoes periods of substantial eclipse, disappearing from the CHIME $400{-}800$ MHz observing band for a large fraction of its orbit, and displays significant dispersion measure and scattering variations throughout its orbit, pointing to the possibility of a circumstellar disk or very dense stellar wind associated with the companion star. Subarcsecond resolution imaging with the Karl G. Jansky Very Large Array unambiguously demonstrates that the companion is a bright, $V \simeq 11$ OBe star, EM* UHA 138, located at a distance of $3.26(14)$ kpc. Archival optical observations of \companion{} approximately suggest a companion mass ranging from $17.5$ M$_{\odot} < M_{\rm c} < 23$ M$_{\odot}$, in turn constraining the orbital inclination angle to $50.3^{\circ} \lesssim i \lesssim 58.3^{\circ}$. With further multi-wavelength followup, PSR J2108+4516 promises to serve as another rare laboratory for the exploration of companion winds, circumstellar disks, and short-term evolution through extended-body orbital dynamics.
Comment: 20 pages, 12 figures, accepted by ApJ
Databáze: arXiv