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Monitoring of the eclipsing Wolf-Rayet ULX in the Circinus galaxy

Published online by Cambridge University Press:  30 December 2019

Yanli Qiu  and
Roberto Soria
Yanli Qiu
Affiliation:
National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Rd, Beijing 100101, China email: qiuyanli824@163.com
Roberto Soria
Affiliation:
College of Astronomy and Space Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China email: rsoria@nao.cas.cn
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Abstract

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. We studied the eclipsing ultraluminous X-ray source CG X-1 in the Circinus galaxy, re-examining two decades of Chandra and XMM-Newton observations. The short binary period (7.21 hr) and high luminosity (LX ≈ 1040 erg s-1) suggest a Wolf-Rayet donor, close to filling its Roche lobe; this is the most luminous Wolf-Rayet X-ray binary known to-date, and a potential progenitor of a gravitational-wave merger. We phase-connect all observations, and show an intriguing dipping pattern in the X-ray lightcurve, variable from orbit to orbit. We interpret the dips as partial occultation of the X-ray emitting region by fast-moving clumps of Compton-thick gas. We suggest that the occulting clouds are fragments of the dense shell swept-up by a bow shock ahead of the compact object, as it orbits in the wind of the more massive donor.

Keywords

X-rays: binariesX-rays: individual (Circinus Galaxy X-1)stars: Wolf-Rayetbinaries: eclipsing

References

Bachetti, M., et al. 2014, Nature, 514, 202 CrossRefGoogle Scholar
Barnard, R., Clark, J. S., & Kolb, U. C. 2008, A&A, 488, 697 Google Scholar
Bauer, F. E., Brandt, W. N., Sambruna, R. M., Chartas, G., Garmire, G. P., Kaspi, S., & Netzer, H. 2001, AJ, 122, 182 CrossRefGoogle Scholar
Bauer, F. E., Dwarkadas, V. V., Brandt, W. N., Immler, S., Smartt, S., Bartel, N., & Bietenholz, M. F. 2008, ApJ, 688, 1210 CrossRefGoogle Scholar
Binder, B., Williams, B. F., Eracleous, M., Garcia, M. R., Anderson, S. F., & Gaetz, T. J. 2011, ApJ, 742, 128 CrossRefGoogle Scholar
Carpano, S., Pollock, A. M. T., Prestwich, A. H., Crowther, P., Wilms, J., Yungelson, L., & Ehle, M. 2007, A&A, 466, L17 Google Scholar
Crowther, P. A., Barnard, R., Carpano, S., Clark, J. S., Dhillon, V. S., & Pollock, A. M. T. 2010, MNRAS, 403, L41 CrossRefGoogle Scholar
Doroshenko, V., Santangelo, A., Nakahira, S., Mihara, T., Sugizaki, M., Matsuoka, M., Nakajima, M., & Makishima, K. 2013, A&A, 554, 37 Google Scholar
Eggelton, P. P. 1983, ApJ, 268, 368 CrossRefGoogle Scholar
Esposito, P., Israel, G. L., Sidoli, L., Mapelli, M., Zampieri, L., & Motta, S. E. 2013, MNRAS, 436, 3380 CrossRefGoogle Scholar
Esposito, P., Israel, G. L., Milisavljevic, D., Mapelli, M., Zampieri, L., Sidoli, L., Fabbiano, G., & Rodríguez Castillo, G. A. 2015 MNRAS, 452, 1112 CrossRefGoogle Scholar
For, B.-Q., Koribalski, B. S., & Jarrett, T. H. 2012, MNRAS, 425, 1934 CrossRefGoogle Scholar
Frank, J., King, A. R., & Lasota, J.-P. 1987, A&A, 178, 137 Google Scholar
Ghosh, K. K., Rappaport, S., Tennant, A. F., Swartz, D. A., Pooley, D., & Madhusudhan, N. 2006, ApJ, 650, 872 CrossRefGoogle Scholar
Hjalmarsdotter, L., Zdziarski, A. A., Szostek, A., & Hannikainen, D. C. 2009, MNRAS, 392, 251 CrossRefGoogle Scholar
Koljonen, K. I. I., Hannikainen, D. C., McCollough, M. L., Pooley, G. G., & Trushkin, S. A. 2010, MNRAS, 406, 307 CrossRefGoogle Scholar
Laycock, S. G. T., Maccarone, T. J., & Christodoulou, D. M. 2015, MNRAS, 452, L31 CrossRefGoogle Scholar
Kong, A. K. H., Di Stefano, R., & Yuan, F. 2004, ApJ, 617, L49 CrossRefGoogle Scholar
Liu, J.-F., Bregman, J. N., Bai, Y., Justham, S., & Crowther, P. 2013, Nature, 503, 500 CrossRefGoogle Scholar
Maccarone, T. J., Lehmer, B. D., Leyder, J. C., Antoniou, V., Hornschemeier, A., Ptak, A., Wik, D., & Zezas, A. 2014, MNRAS, 439, 3064 CrossRefGoogle Scholar
McCollough, M. L., Corrales, L., & Dunham, M. M. 2016, ApJ, 830, L36 CrossRefGoogle Scholar
Mineo, S., Gilfanov, M., & Sunyaev, R. 2012, MNRAS, 419, 2095 CrossRefGoogle Scholar
Motch, C., Pakull, M. W., Soria, R., Grisé, F., & Pietrzyski, G. 2014, Nature, 514, 198 CrossRefGoogle Scholar
Ohsuga, K., & Mineshige, S. 2011, ApJ, 736, 2 CrossRefGoogle Scholar
Park, K. H., & Ricotti, M. 2013, ApJ, 767, 163 CrossRefGoogle Scholar
Poutanen, J., Lipunova, G., Fabrika, S., Butkevich, A. G., & Abolmasov, P. 2007, MNRAS, 377, 1187 CrossRefGoogle Scholar
Prestwich, A. H., et al. 2007, ApJ, 669, L21 CrossRefGoogle Scholar
Ro, S., & Matzner, C. D. 2016, ApJ, 821, 109 CrossRefGoogle Scholar
Schlafly, E. F., & Finkbeiner, D. P. 2011, ApJ, 737, 103 CrossRefGoogle Scholar
Shakura, N. I., & Sunyaev, R. A. 1973, A&A, 24, 337 Google Scholar
Silverman, J. M., & Filippenko, A. V. 2008, ApJ, 678, L17 CrossRefGoogle Scholar
Tully, R. B., Rizzi, L., Shaya, E. J., Courtois, H. M., Makarov, D. I., & Jacobs, B. A. 2009, AJ, 138, 323 CrossRefGoogle Scholar
Urquhart, R. T., & Soria, R. 2016a, ApJ, 831, 56 CrossRefGoogle Scholar
Urquhart, R. T., & Soria, R. 2016b, MNRAS, 456, 1859 CrossRefGoogle Scholar
Usov, V. V. 1991, MNRAS, 252, 49 CrossRefGoogle Scholar
Weaver, R., McCray, R., Castor, J., Shapiro, P., & Moore, R. 1977, ApJ, 218, 377 CrossRefGoogle Scholar
Weisskopf, M. C., Wu, K., Tennant, A. F., Swartz, D. A., & Ghosh, K. K. 2004, ApJ, 605, 360 CrossRefGoogle Scholar
White, N. E., & Swank, J. H. 1982, ApJ, 253, L61 CrossRefGoogle Scholar
Zdziarski, A. A., Maitra, C., Frankowski, A., Skinner, G. K., & Misra, R. 2012, MNRAS, 426, 1031 CrossRefGoogle Scholar