Probing the Pulsar Population of Terzan 5 via Spectral Modeling
Ndiyavala H, Venter C, Johnson TJ, Harding AK, Smith DA, Eger P, Kopp A, Van Der Walt DJ (2019)
Publication Type: Journal article
Publication year: 2019
Journal
Book Volume: 880
Journal Issue: 1
Abstract
Terzan 5 is the only Galactic globular cluster that has plausibly been detected at very high energies by the High Energy Stereoscopic System. It has an unexpectedly asymmetric very high energy morphology that is offset from the cluster center, in addition to a large-scale, offset radio structure and compact diffuse X-ray emission associated with this cluster. We present new data from the Fermi Large Area Telescope on this source. We model the updated broadband spectral energy distribution, attributing this to cumulative pulsed emission from a population of embedded millisecond pulsars, as well as unpulsed emission from the interaction of their leptonic winds with the ambient magnetic and soft-photon fields. In particular, our model invokes unpulsed synchrotron and inverse Compton components to model the radio and TeV data and cumulative pulsed curvature radiation to fit the Fermi data, and it explains the hard Chandra X-ray spectrum via a "new" cumulative synchrotron component from electron-positron pairs within the pulsar magnetospheres that has not been implemented before. We find reasonable spectral fits for plausible model parameters. We also derive constraints on the millisecond pulsar luminosity function using the diffuse X-ray data and the Chandra sensitivity. Future higher-quality spectral and spatial data will help discriminate between competing scenarios (such as dark matter annihilation, white dwarf winds, or hadronic interactions) proposed for the broadband emission, as well as constraining degenerate model parameters.
Authors with CRIS profile
Involved external institutions
Noordwes-Universiteit / North-West University
South Africa (ZA)
George Mason University
United States (USA) (US)
National Aeronautics and Space Administration (NASA)
United States (USA) (US)
Université Bordeaux 1, Sciences et Technologies
France (FR)
South Africa (ZA)
George Mason University
United States (USA) (US)
National Aeronautics and Space Administration (NASA)
United States (USA) (US)
Université Bordeaux 1, Sciences et Technologies
France (FR)
How to cite
APA:
Ndiyavala, H., Venter, C., Johnson, T.J., Harding, A.K., Smith, D.A., Eger, P.,... Van Der Walt, D.J. (2019). Probing the Pulsar Population of Terzan 5 via Spectral Modeling. Astrophysical Journal, 880(1). https://dx.doi.org/10.3847/1538-4357/ab24ca
MLA:
Ndiyavala, H., et al. "Probing the Pulsar Population of Terzan 5 via Spectral Modeling." Astrophysical Journal 880.1 (2019).
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