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Pulse Morphology of the Galactic Center Magnetar PSR J1745–2900

Pearlman, Aaron B. and Majid, Walid A. and Prince, Thomas A. and Kocz, Jonathon and Horiuchi, Shinji (2018) Pulse Morphology of the Galactic Center Magnetar PSR J1745–2900. Astrophysical Journal, 866 (2). Art. No. 160. ISSN 1538-4357. http://resolver.caltech.edu/CaltechAUTHORS:20181024-142448369

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Abstract

We present results from observations of the Galactic Center magnetar, PSR J1745–2900, at 2.3 and 8.4 GHz with the NASA Deep Space Network 70 m antenna, DSS-43. We study the magnetar's radio profile shape, flux density, radio spectrum, and single pulse behavior over a ~1 year period between MJDs 57233 and 57621. In particular, the magnetar exhibits a significantly negative average spectral index of ⟨α⟩ = -1.86 ± 0.02 when the 8.4 GHz profile is single-peaked, which flattens considerably when the profile is double-peaked. We have carried out an analysis of single pulses at 8.4 GHz on MJD 57479 and find that giant pulses and pulses with multiple emission components are emitted during a significant number of rotations. The resulting single pulse flux density distribution is incompatible with a log-normal distribution. The typical pulse width of the components is ~1.8 ms, and the prevailing delay time between successive components is ~7.7 ms. Many of the single pulse emission components show significant frequency structure over bandwidths of ~100 MHz, which we believe is the first observation of such behavior from a radio magnetar. We report a characteristic single pulse broadening timescale of ⟨τ_d⟩ = 6.9 ± 0.2 at 8.4 GHz. We find that the pulse broadening is highly variable between emission components and cannot be explained by a thin scattering screen at distances ≳1 kpc. We discuss possible intrinsic and extrinsic mechanisms for the magnetar's emission and compare our results to other magnetars, high magnetic field pulsars, and fast radio bursts.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.3847/1538-4357/aade4dDOIArticle
https://arxiv.org/abs/1809.02140arXivDiscussion Paper
ORCID:
AuthorORCID
Pearlman, Aaron B.0000-0002-8912-0732
Majid, Walid A.0000-0002-4694-4221
Prince, Thomas A.0000-0002-8850-3627
Kocz, Jonathon0000-0003-0249-7586
Additional Information:© 2018 The American Astronomical Society. Received 2018 April 30; revised 2018 August 23; accepted 2018 August 30; published 2018 October 24. We thank the referee for valuable comments that helped us improve this paper. We also thank Professor Roger Blandford for insightful discussions and suggestions. A. B. Pearlman acknowledges support by the Department of Defense (DoD) through the National Defense Science and Engineering Graduate Fellowship (NDSEG) Program and by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469. We thank the Jet Propulsion Laboratory and Caltech's President's and Director's Fund for partial support at JPL and the Caltech campus. We also thank Joseph Lazio and Charles Lawrence for providing programmatic support for this work. A portion of this research was performed at the Jet Propulsion Laboratory, California Institute of Technology and the Caltech campus, under a Research and Technology Development Grant through a contract with the National Aeronautics and Space Administration. U.S. government sponsorship is acknowledged.
Group:Space Radiation Laboratory
Funders:
Funding AgencyGrant Number
Department of Defense (DOD)UNSPECIFIED
National Defense Science and Engineering Graduate (NDSEG) FellowshipUNSPECIFIED
NSF Graduate Research FellowshipDGE-1144469
NASA/JPL/CaltechUNSPECIFIED
JPL President and Director's FundUNSPECIFIED
Subject Keywords:Galaxy: center – pulsars: individual (PSR J1745–2900) – scattering – stars: magnetars – stars: neutron
Record Number:CaltechAUTHORS:20181024-142448369
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20181024-142448369
Official Citation:Aaron B. Pearlman et al 2018 ApJ 866 160
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90401
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:25 Oct 2018 16:33
Last Modified:29 Oct 2018 22:59

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