An Analysis of the North Polar Spur Using HaloSat
| dc.contributor.author | LaRocca, Daniel M. | |
| dc.contributor.author | Kaaret, Philip | |
| dc.contributor.author | Kuntz, K. D. | |
| dc.contributor.author | Hodges-Kluck, Edmund | |
| dc.contributor.author | Zajczyk, Anna | |
| dc.contributor.author | Bluem, Jesse | |
| dc.contributor.author | Ringuette, Rebecca | |
| dc.contributor.author | Jahoda, Keith M. | |
| dc.date.accessioned | 2020-12-11T16:44:03Z | |
| dc.date.available | 2020-12-11T16:44:03Z | |
| dc.date.issued | 2020-11-20 | |
| dc.description.abstract | We present HaloSat X-ray observations of the entirety of the bright X-ray emitting feature known as the North Polar Spur (NPS). The large field of view of HaloSat enabled coverage of the entire bright NPS in only 14 fields, which were each observed for ≈30,000 s. We find that the NPS fields are distinct in both brightness and spectral shape from the surrounding halo fields. We fit the NPS as two thermal components in ionization equilibrium with temperatures kT keV cool » 0.087 and kT keV hot » 0.28 . We note a temperature gradient in the NPS hot component with an inner arc temperature warmer than the outer arc. The emission measures we find for the cool component of the NPS is a factor of 3–5 greater than that of the hot component, which suggests that the bulk of the NPS material is in the ≈0.1 keV component. We evaluate distance estimates of 0.4 and 8.0 kpc for the NPS. Our findings suggest a preference for a distant NPS with an energy of ≈ 6 × 10⁵⁴ erg, an age of ≈ 10 Myr, and pressures consistent with a 10μG magnetic field associated with the Fermi bubbles. The electron density ≈10 × 10⁻³ cm⁻³ is consistent with estimates for the shock region surrounding a Galactic-scale event. | en_US |
| dc.description.sponsorship | This research was supported by NASA grant No. NNX15AU57G. This research was also supported by the NASA Iowa Space Grant under award No. NNX16AL88H. We acknowledge Steven Spangler, Cornelia Lang, and Casey DeRoo for their useful comments discussions that helped to improve the work. We acknowledge our support from NASA GSFC particularly the work of Thomas Johnson, the hard work of all the individuals at the University of Iowa that helped make HaloSat a success, the Blue Canyon Technologies team for their work on the spacecraft bus and for acting as the mission operation center, and the WFF UHF Ground Station Team for their support of HaloSat in orbit. We acknowledge the contribution from our anonymous reviewer, whose comments helped to clarify the presentation of this work. | en_US |
| dc.description.uri | https://iopscience.iop.org/article/10.3847/1538-4357/abbdfd/meta | en_US |
| dc.format.extent | 11 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier | doi:10.13016/m2x1hu-zdxc | |
| dc.identifier.citation | Daniel M. LaRocca et al., An Analysis of the North Polar Spur Using HaloSat (2020), ApJ 904 54, DOI: https://doi.org/10.3847/1538-4357/abbdfd | en_US |
| dc.identifier.uri | https://doi.org/10.3847/1538-4357/abbdfd | |
| dc.identifier.uri | http://hdl.handle.net/11603/20235 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | IOP | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology | |
| dc.relation.ispartof | UMBC Faculty Collection | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.rights | Public Domain Mark 1.0 | * |
| dc.rights | This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. | |
| dc.rights.uri | http://creativecommons.org/publicdomain/mark/1.0/ | * |
| dc.title | An Analysis of the North Polar Spur Using HaloSat | en_US |
| dc.type | Text | en_US |