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The young Be-star binary Circinus X-1

Published online by Cambridge University Press:  30 December 2019

Norbert S. Schulz
Affiliation:
Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA email: nss@space.mit.edu
Timothy E. Kallman
Affiliation:
Goddard Space Flight Center, NASA, Green Belt, MD, USA email: tim@milkyway.gsfc.nasa.gov
Sebastian Heinz
Affiliation:
Department of Astronomy, University of Wisconsin, Madison, WI, USA email: heinzs@astro.wisc.edu
Paul Sell
Affiliation:
Department of Physics, University of Crete, Heraklion, Greece email: psell@physics.uoc.gr
Peter Jonker
Affiliation:
Department of Astrophysics, Radboud University, Nijmegen, The Netherlands email: peterj@sron.nl
William N. Brandt
Affiliation:
Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvenia State Univerity, University Park, PA, USA email: niel@astro.psu.edu
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Abstract

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Cir X-1 is a young X-ray binary exhibiting X-ray flux changes of four orders of magnitude over several decades. It has been observed many times since the launch of the Chandra X-ray Observatory with high energy transmission grating spectrometer and each time the source gave us a vastly different look. At its very lowest X-ray flux we found a single 1.7 keV blackbody spectrum with an emission radius of 0.5 km. Since the neutron star in Cir X-1 is only few thousand years old we identify this as emission from an accretion column since at this youth the neutron star is assumed to be highly magnetized. At an X-ray flux of 1.8×10−11 erg cm−2 s−1 this implies a moderate magnetic field of a few times of 1011 G. The photoionized X-ray emission line properties at this low flux are consistent with B5-type companion wind. We suggest that Cir X-1 is a very young Be-star binary.

Type
Contributed Papers
Copyright
© International Astronomical Union 2019 

References

Behrend, R. & Maeder, A. 2001 Astron. & Astrophys., 373, 190 10.1051/0004-6361:20010585CrossRefGoogle Scholar
Bhattacharya, D., & van den Heuvel, E. P. J. 1991, Phys. Rep., 203, 1 10.1016/0370-1573(91)90064-SCrossRefGoogle Scholar
Blundell, K. M., Bowler, M. G. & Schmidtobreick, L. 2008 ApJ, 678, L47 10.1086/588027CrossRefGoogle Scholar
Brandt, N. & Podsiadlowski, P. 1995 MNRAS, 274, 461 10.1093/mnras/274.2.461CrossRefGoogle Scholar
Clarkson, W. L., Charles, P. A. & Onyett, W. 2004 MNRAS, 348, 458 10.1111/j.1365-2966.2004.07293.xCrossRefGoogle Scholar
Cowley, A. P., Hutchings, J. B. & Crampton, D. 1988 ApJ, 333, 906 10.1086/166799CrossRefGoogle Scholar
Halpern, J. P. & Gotthelf, E. V. 2010 ApJ, 709, 436 10.1088/0004-637X/709/1/436CrossRefGoogle Scholar
Hasinger, G. & van der Klis, M. 1989 Astron. & Astrophys., 225, 79 Google Scholar
Heinz, S., Sell, P., Fender, R. P., Jonker, P. G., Brandt, W. N., Calvelo-Santos, D. E., Tzioumis, A. K., Nowak, M. A., Schulz, N. S., Wijnands, R., & van der Klis, M. 2013 ApJ, 779, 171 10.1088/0004-637X/779/2/171CrossRefGoogle Scholar
Hénault-Brunet, V., Oskinova, L. M., Guerrero, M. A. et al. 2012 ApJ, 619, 503 Google Scholar
Homan, J., van der Klis, M., Fridriksson, J. K., et al. 2010, ApJ, 719, 201 10.1088/0004-637X/719/1/201CrossRefGoogle Scholar
Jonker, P. G., Nelemans, G. & Bassa, C. G. 2007 MNRAS, 374, 999 10.1111/j.1365-2966.2006.11210.xCrossRefGoogle Scholar
Kaluzienski, L. J., Holt, S. S., Boldt, E. A., & Serlemitsos, P. J. 1976 ApJ Letters, 208, 71L 10.1086/182235CrossRefGoogle Scholar
Kaspi, V. 2010 Proceeding of the National Academy of Science, 107, 7147 10.1073/pnas.1000812107CrossRefGoogle Scholar
Lau, R. M., Hankins, M. J., Herter, T. L. et al. 2016 ApJ, 818, 117 10.3847/0004-637X/818/2/117CrossRefGoogle Scholar
Lewin, W. H. G., van Paradijs, J. & van den Heuvel, E. P. J. 1995 Cambridge Astrophysics Series, Vol. 26 Google Scholar
Linares, M., et al. 2010 ApJ Letters, 719, L84 10.1088/2041-8205/719/1/L84CrossRefGoogle Scholar
Margon, B., Lampton, M., Bowyer, S., & Cruddace, R. 1971 ApJ Letters, 169, L23 10.1086/180806CrossRefGoogle Scholar
Moneti, A. 1992 Astron. & Astrophys., 260, 7 Google Scholar
Papitto, A., Riggio, A., di Salvo, T., Burderi, L., D’Aì, A., Iaria, R., Bozzo, E., & Menna, M. T. 2010 MNRAS, 407, 2575 10.1111/j.1365-2966.2010.17090.xCrossRefGoogle Scholar
Parkinson, P. M. S., Tournear, D. M., Bloom, E. D. et al. 2003 ApJ, 595, 333 10.1086/377193CrossRefGoogle Scholar
Reig, P. & Roche, P. 1999 MNRAS, 306, 100 10.1046/j.1365-8711.1999.02473.xCrossRefGoogle Scholar
Reig, P. 2011 Ap& SS, 332, 1 Google Scholar
Schulz, N. S., Hasinger, G. & Trumper, J. 1989 Astron. & Astrophys., 225, 48 Google Scholar
Schulz, N. S., Kallman, T. E, Galloway, D. K., & Brandt, W. N. 2008 ApJ, 572, 171 Google Scholar
Schulz, N. S., Kallman, T. E, Heinz, S., Sell, P., Jonker, P. G., & Brandt, W. N. 2018 ApJ, submittedGoogle Scholar
Shirey, R. E., Bradt, H. V. & Levine, A. M. 1999 ApJ, 517, 472 10.1086/307188CrossRefGoogle Scholar
Steward, F.., Charles, P. A., Foster, D. L. et al. 2012 ApJ, 759, 123 10.1088/0004-637X/759/2/123CrossRefGoogle Scholar
Tauris, T. M., Fender, R. P., van den Heuvel, E. P. J., Johnston, H. M., & Wu, K. 1999 MNRAS, 310, 1165 10.1046/j.1365-8711.1999.03068.xCrossRefGoogle Scholar
Tauris, T. M., Sanyal, D., Yoon, S.-C., & Langer, N. 2013 Astron. & Astrophys., 558, A39 10.1051/0004-6361/201321662CrossRefGoogle Scholar
Tennant, A. F., Fabian, A. C., & Shafer, R. A. 1986 MNRAS, 221, 27 10.1093/mnras/221.1.27PCrossRefGoogle Scholar
Tennant, A. F. 1987 MNRAS, 226, 971 10.1093/mnras/226.4.971CrossRefGoogle Scholar
Whelan, J. A. J., et al. 1977 MNRAS, 181, 259 10.1093/mnras/181.2.259CrossRefGoogle Scholar