Simultaneous X-ray and radio observations of the transitional millisecond pulsar candidate CXOU J110926.4-650224. The discovery of a variable radio counterpart
| Autor: | Zelati, F. Coti, Hugo, B., Torres, D. F., de Martino, D., Papitto, A., Buckley, D. A. H., Russell, T. D., Campana, S., Van Rooyen, R., Bozzo, E., Ferrigno, C., Li, J., Migliari, S., Monageng, I., Rea, N., Serylak, M., Stappers, B. W., Titus, N. |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | A&A 655, A52 (2021) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1051/0004-6361/202141431 |
| Popis: | We present the results of simultaneous observations of the transitional millisecond pulsar (tMSP) candidate CXOU J110926.4-650224 with the XMM-Newton satellite and the MeerKAT telescope. The source was found at an average X-ray luminosity of $L_{\rm X}\simeq7\times10^{33}$ erg s$^{-1}$ over the 0.3-10 keV band (assuming a distance of 4 kpc) and displayed a peculiar variability pattern in the X-ray emission, switching between high, low and flaring modes on timescales of tens of seconds. A radio counterpart was detected at a significance of 7.9$\sigma$ with an average flux density of $\simeq$33$\mu$Jy at 1.28 GHz. It showed variability over the course of hours and emitted a $\simeq$10-min long flare just a few minutes after a brief sequence of multiple X-ray flares. No clear evidence for a significant correlated or anticorrelated variability pattern was found between the X-ray and radio emissions over timescales of tens of minutes and longer. CXOU J110926.4-650224 was undetected at higher radio frequencies in subsequent observations performed with the Australia Telescope Compact Array, when the source was still in the same X-ray sub-luminous state observed before, down to a flux density upper limit of 15$\mu$Jy at 7.25 GHz (at 3$\sigma$). We compare the radio emission properties of CXOU J110926.4-650224 with those observed in known and candidate tMSPs and discuss physical scenarios that may account for its persistent and flaring radio emissions. Comment: 10 pages, 4 figures. Accepted for publication on A&A |
| Databáze: | arXiv |
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