The young Be-star binary Circinus X-1

Norbert S. Schulz; Timothy E. Kallman; Sebastian Heinz; Paul Sell; Peter Jonker; William N. Brandt

doi:10.1017/S1743921319002497

The young Be-star binary Circinus X-1

Norbert S. Schulz, Timothy E. Kallman, Sebastian Heinz, Paul Sell, Peter Jonker, William N. Brandt

Research output: Contribution to journal › Article › peer-review

Abstract

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.

Original language	English (US)
Pages (from-to)	125-130
Number of pages	6
Journal	Proceedings of the International Astronomical Union
DOIs	https://doi.org/10.1017/S1743921319002497
State	Accepted/In press - Jan 1 2019

All Science Journal Classification (ASJC) codes

Medicine (miscellaneous)
Astronomy and Astrophysics
Nutrition and Dietetics
Public Health, Environmental and Occupational Health
Space and Planetary Science

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1017/S1743921319002497

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title = "The young Be-star binary Circinus X-1",

abstract = "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.",

author = "Schulz, {Norbert S.} and Kallman, {Timothy E.} and Sebastian Heinz and Paul Sell and Peter Jonker and Brandt, {William N.}",

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doi = "10.1017/S1743921319002497",

language = "English (US)",

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AU - Schulz, Norbert S.

AU - Kallman, Timothy E.

AU - Heinz, Sebastian

AU - Sell, Paul

AU - Jonker, Peter

AU - Brandt, William N.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - 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.

AB - 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.

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JF - Proceedings of the International Astronomical Union

ER -

The young Be-star binary Circinus X-1

Abstract

All Science Journal Classification (ASJC) codes

UN SDGs

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