Systematically Revisiting All NuSTAR Spins of Black Holes in X-Ray Binaries

Fuente: arXiv
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Main Authors: Draghis, Paul A., Miller, Jon M., Costantini, Elisa, Gallo, Luigi C., Reynolds, Mark, Tomsick, John A., Zoghbi, Abderahmen
Format: Preprint
Published: 2023
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author Draghis, Paul A.
Miller, Jon M.
Costantini, Elisa
Gallo, Luigi C.
Reynolds, Mark
Tomsick, John A.
Zoghbi, Abderahmen
author_facet Draghis, Paul A.
Miller, Jon M.
Costantini, Elisa
Gallo, Luigi C.
Reynolds, Mark
Tomsick, John A.
Zoghbi, Abderahmen
contents We extend our recent work on black hole spin in X-ray binary systems to include an analysis of 189 archival NuSTAR observations from 24 sources. Using self-consistent data reduction pipelines, spectral models, and statistical techniques, we report an unprecedented and uniform sample of 36 stellar-mass black hole spin measurements based on relativistic reflection. This treatment suggests that prior reports of low spins in a small number of sources were generally erroneous: our comprehensive treatment finds that those sources tend to harbor black holes with high spin values. Overall, within $1σ$ uncertainty, $\sim86\%$ of the sample are consistent with $a \geq 0.95$, $\sim94\%$ of the sample are consistent with $a\geq 0.9$, and $100\%$ is consistent with $a\geq 0.7$ (the theoretical maximum for neutron stars; $a = cJ/GM^{2}$). We also find that the high-mass X-ray binaries (those with A-, B-, or O-type companions) are consistent with $a\geq 0.9$ within the $1σ$ errors; this is in agreement with the low-mass X-ray binary population and may be especially important for comparisons to black holes discovered in gravitational wave events. In some cases, different spectra from the same source yield similar spin measurements but conflicting values for the inclination of the inner disk; we suggest that this is due to variable disk winds obscuring the blue wing of the relativistic Fe K emission line. We discuss the implications of our measurements, the unique view of systematic uncertainties enabled by our treatment, and future efforts to characterize black hole spins with new missions.
format Preprint
id arxiv_https___arxiv_org_abs_2311_16225
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Systematically Revisiting All NuSTAR Spins of Black Holes in X-Ray Binaries
Draghis, Paul A.
Miller, Jon M.
Costantini, Elisa
Gallo, Luigi C.
Reynolds, Mark
Tomsick, John A.
Zoghbi, Abderahmen
High Energy Astrophysical Phenomena
We extend our recent work on black hole spin in X-ray binary systems to include an analysis of 189 archival NuSTAR observations from 24 sources. Using self-consistent data reduction pipelines, spectral models, and statistical techniques, we report an unprecedented and uniform sample of 36 stellar-mass black hole spin measurements based on relativistic reflection. This treatment suggests that prior reports of low spins in a small number of sources were generally erroneous: our comprehensive treatment finds that those sources tend to harbor black holes with high spin values. Overall, within $1σ$ uncertainty, $\sim86\%$ of the sample are consistent with $a \geq 0.95$, $\sim94\%$ of the sample are consistent with $a\geq 0.9$, and $100\%$ is consistent with $a\geq 0.7$ (the theoretical maximum for neutron stars; $a = cJ/GM^{2}$). We also find that the high-mass X-ray binaries (those with A-, B-, or O-type companions) are consistent with $a\geq 0.9$ within the $1σ$ errors; this is in agreement with the low-mass X-ray binary population and may be especially important for comparisons to black holes discovered in gravitational wave events. In some cases, different spectra from the same source yield similar spin measurements but conflicting values for the inclination of the inner disk; we suggest that this is due to variable disk winds obscuring the blue wing of the relativistic Fe K emission line. We discuss the implications of our measurements, the unique view of systematic uncertainties enabled by our treatment, and future efforts to characterize black hole spins with new missions.
title Systematically Revisiting All NuSTAR Spins of Black Holes in X-Ray Binaries
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2311.16225