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Skip to Search Results- 12Heinke, Craig O.
- 12Sivakoff, Gregory Robert
- 7Bahramian, Arash
- 6Altamirano, Diego
- 6Wijnands, Rudy
- 5Chomiuk, Laura
- 10X-Rays: Binaries
- 7Stars: Neutron
- 6Accretion
- 5Accretion Discs
- 3Globular Clusters: Individual: Terzan 5
- 3Stars: Black Holes
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Understanding X-ray irradiation in low-mass X-ray binaries directly from their light-curves
Download2018-01-01
Sivakoff, Gregory Robert, Tetarenko, Bailey E., Dubus, G., Lasota, Jean-Pierre, Heinke, Craig O.
The X-ray light curves of the recurring outbursts observed in low-mass X-ray binaries provide strong test beds for constraining (still) poorly understood disc-accretion processes. These light curves act as a powerful diagnostic to probe the physics behind the mechanisms driving mass inflow and...
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2018-01-01
Shaw, A. W., Heinke, Craig O., Mukai, K., Sivakoff, Gregory Robert, Tomsick, John A., Rana, Vikram
The X-ray spectra of intermediate polars can be modelled to give a direct measurement of white dwarf mass. Here, we fit accretion column models to NuSTAR spectra of three intermediate polars; V709 Cas, NY Lup, and V1223 Sgr in order to determine their masses. From fits to 3–78 keV spectra, we...
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Extreme quiescent variability of the transient neutron star low-mass X-ray binary EXO 1745-248 in Terzan 5
Download2018-01-01
Rivera Sandoval, L. E., Wijnands, Rudy, Denegaar, Nathalie, Cavecchi, Y., Heinke, Craig O., Cackett, Edward M., Homan, Jeroen, Altamirano, Diego, Bahramian, Arash, Sivakoff, Gregory Robert, Miller, Jon M., Parikh, Aastha S.
EXO 1745−248 is a transient neutron star low-mass X-ray binary that resides in the globular cluster Terzan 5. We studied the transient during its quiescent state using 18 Chandra observations of the cluster acquired between 2003 and 2016. We found an extremely variable source, with a luminosity...
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2018-01-01
Tudor, Vlad, Miller-Jones, James C. A., Knigge, C., Maccarone, Thomas J., Tauris, T. M., Bahramian, Arash, Chomiuk, Laura, Heinke, Craig O., Sivakoff, Gregory Robert, Strader, Jay, Plotkin, Richard M., Soria, Roberto, Albrow, M. D., Anderson, G. E., van den Berg, Maureen, Bernardini, Federico, Bogdanov, Slavko, Britt, Christopher. T., Russell, D. M., Zurek, David R.
To confirm the nature of the donor star in the ultracompact X-ray binary candidate 47 Tuc X9, we obtained optical spectra (3000–10 000 Å) with the Hubble Space Telescope / Space Telescope Imaging Spectrograph. We find no strong emission or absorption features in the spectrum of X9. In particular,...
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2018-01-01
Sanna, Andrea, Bahramian, Arash, Bozzo, E., Heinke, Craig O., Wijnands, Rudy, Degenaar, Nathalie, Maccarone, T., Riggio, Alessandro, Di Salvo, Tiziana, Iaria, Rosario, Burgay, M., Possenti, Andrea, Ferrigno, C., Papitto, A., Sivakoff, Gregory Robert, D'Amico, Nicolo, Burderi, Luciano, Altamirano, Diego
We report the discovery of X-ray pulsations at 105.2 Hz (9.5 ms) from the transient X-ray binary IGR J16597–3704 using NuSTAR and Swift. The source was discovered by INTEGRAL in the globular cluster NGC 6256 at a distance of 9.1 kpc. The X-ray pulsations show a clear Doppler modulation that...
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2017-01-01
Bahramian, Arash, Heinke, Craig O., Tudor, Vlad, Miller-Jones, James. C. A., Bogdanov, Slavko, Maccarone, Thomas J., Knigge, C., Sivakoff, Gregory Robert, Chomiuk, Laura, Strader, Jay, Garcia, Javier A., Kallman, Timothy
47 Tuc X9 is a low-mass X-ray binary (LMXB) in the globular cluster 47 Tucanae, and was previously thought to be a cataclysmic variable. However, Miller-Jones et al. recently identified a radio counterpart to X9 (inferring a radio/X-ray luminosity ratio consistent with black hole LMXBs), and...
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2016-01-01
Bahramian, Arash, Sivakoff, Gregory Robert, Tremou, Evangelia, Linares, Manuel, Tudor, Vlad, Miller-Jones, James. C. A., Heinke, Craig O., Chomiuk, Laura, Strader, Jay, Altamirano, Diego, Degenaar, Nathalie, Maccarone, Thomas J., Patruno, A., Sanna, Andrea, Wijnands, Rudy, Tetarenko, Alexandra Jean
We present the results of Very Large Array, Australia Telescope Compact Array, and Swift X-ray Telescope observations of the 2015 outburst of the transient neutron star X-ray binary (NSXB), EXO 1745−248, located in the globular cluster Terzan 5. Combining (near-) simultaneous radio and X-ray...
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2016-01-01
Bahramian, Arash, Tetarenko, Alexandra Jean, Sivakoff, Gregory Robert, Tremou, Evangelia, Linares, Manuel, Tudor, Vlad, Miller-Jones, James C. A., Heinke, Craig O., Chomiuk, Laura, Strader, Jay, Altamirano, Diego, Degenaar, Nathalie, Maccarone, Thomas J., Patruno, A., Sanna, Andrea, Wijnands, Rudy
The paper “Disc-Jet Coupling in the Terzan 5 Neutron Star X-ray Binary EXO 1745−248” was published as Tetarenko et al. 2016, MNRAS, 460, 345–355. In Section 3.3 of the paper there is a minor error in equation (1). The correct equation is as follows, (logLR−logLR,c)=logξ+β(logLX−logLX,c). (1) The...
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2015-01-01
Degenaar, Nathalie, Wijnands, Rudy, Bahramian, Arash, Sivakoff, Gregory Robert, Heinke, Craig O., Brown, E. F., Fridriksson, Joel K., Homan, Jeroen, Cackett, Edward M., Cumming, A., Miller, Jon M., Altamirano, Diego, Pooley, David
When neutron stars reside in transient X-ray binaries, their crustal layers become heated during accretion outbursts and subsequently cool in quiescence. Observing and modelling this thermal response has yielded valuable insight into the physics of neutron star crusts. However, one unresolved...
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Deep radio imaging of 47 Tuc identifies the peculiar X-ray source X9 as a new black hole candidate
Download2015-01-01
Miller-Jones, James C. A., Strader, Jay, Heinke, Craig O., Maccarone, Thomas J., van den Berg, Maureen, Knigge, C., Chomiuk, Laura, Noyola, Eva, Russell, Thomas D., Seth, Anil C., Sivakoff, Gregory Robert
We report the detection of steady radio emission from the known X-ray source X9 in the globular cluster 47 Tuc. With a double-peaked C IV emission line in its ultraviolet spectrum providing a clear signature of accretion, this source had been previously classified as a cataclysmic variable. In...