Large Magneto-ionic Variations toward the Galactic Center Magnetar, PSR J1745-2900

G. Desvignes; R. P. Eatough; U. L. Pen; K. J. Lee; S. A. Mao; R. Karuppusamy; D. H.F.M. Schnitzeler; H. Falcke; M. Kramer; O. Wucknitz; L. G. Spitler; P. Torne; K. Liu; G. C. Bower; I. Cognard; A. G. Lyne; B. W. Stappers

doi:10.3847/2041-8213/aaa2f8

Large Magneto-ionic Variations toward the Galactic Center Magnetar, PSR J1745-2900

G. Desvignes, R. P. Eatough, U. L. Pen, K. J. Lee, S. A. Mao, R. Karuppusamy, D. H.F.M. Schnitzeler, H. Falcke, M. Kramer, O. Wucknitz, L. G. Spitler, P. Torne, K. Liu, G. C. Bower, I. Cognard, A. G. Lyne, B. W. Stappers

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Abstract

Polarized radio emission from PSR J1745-2900 has already been used to investigate the strength of the magnetic field in the Galactic center (GC), close to Sagittarius A∗. Here we report how persistent radio emission from this magnetar, for over four years since its discovery, has revealed large changes in the observed Faraday rotation measure (RM), by up to 3500 rad m^-2 (a 5% fractional change). From simultaneous analysis of the dispersion measure, we determine that these fluctuations are dominated by variations in either the projected magnetic field or the free electron content within the GC, along the changing line of sight to the rapidly moving magnetar. From a structure function analysis of RM variations, and a recent epoch of rapid change of RM, we determine a minimum scale of magneto-ionic fluctuations of size ∼2 au at the GC distance, inferring PSR J1745-2900 is just ∼0.1 pc behind an additional scattering screen.

Original language	English
Article number	L12
Journal	Astrophysical Journal Letters
Volume	852
Issue number	1
Early online date	3 Jan 2018
DOIs	https://doi.org/10.3847/2041-8213/aaa2f8
Publication status	Published - 2018

Keywords

Galaxy: center
magnetic fields
pulsars: individual (J1745-2900)

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Desvignes, G., Eatough, R. P., Pen, U. L., Lee, K. J., Mao, S. A., Karuppusamy, R., Schnitzeler, D. H. F. M., Falcke, H., Kramer, M., Wucknitz, O., Spitler, L. G., Torne, P., Liu, K., Bower, G. C., Cognard, I., Lyne, A. G., & Stappers, B. W. (2018). Large Magneto-ionic Variations toward the Galactic Center Magnetar, PSR J1745-2900. Astrophysical Journal Letters, 852(1), Article L12. https://doi.org/10.3847/2041-8213/aaa2f8

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title = "Large Magneto-ionic Variations toward the Galactic Center Magnetar, PSR J1745-2900",

abstract = "Polarized radio emission from PSR J1745-2900 has already been used to investigate the strength of the magnetic field in the Galactic center (GC), close to Sagittarius A∗. Here we report how persistent radio emission from this magnetar, for over four years since its discovery, has revealed large changes in the observed Faraday rotation measure (RM), by up to 3500 rad m-2 (a 5% fractional change). From simultaneous analysis of the dispersion measure, we determine that these fluctuations are dominated by variations in either the projected magnetic field or the free electron content within the GC, along the changing line of sight to the rapidly moving magnetar. From a structure function analysis of RM variations, and a recent epoch of rapid change of RM, we determine a minimum scale of magneto-ionic fluctuations of size ∼2 au at the GC distance, inferring PSR J1745-2900 is just ∼0.1 pc behind an additional scattering screen.",

keywords = "Galaxy: center, magnetic fields, pulsars: individual (J1745-2900)",

author = "G. Desvignes and Eatough, {R. P.} and Pen, {U. L.} and Lee, {K. J.} and Mao, {S. A.} and R. Karuppusamy and Schnitzeler, {D. H.F.M.} and H. Falcke and M. Kramer and O. Wucknitz and Spitler, {L. G.} and P. Torne and K. Liu and Bower, {G. C.} and I. Cognard and Lyne, {A. G.} and Stappers, {B. W.}",

year = "2018",

doi = "10.3847/2041-8213/aaa2f8",

language = "English",

volume = "852",

journal = "Astrophysical Journal Letters",

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publisher = "American Astronomical Society",

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Desvignes, G, Eatough, RP, Pen, UL, Lee, KJ, Mao, SA, Karuppusamy, R, Schnitzeler, DHFM, Falcke, H, Kramer, M, Wucknitz, O, Spitler, LG, Torne, P, Liu, K, Bower, GC, Cognard, I, Lyne, AG & Stappers, BW 2018, 'Large Magneto-ionic Variations toward the Galactic Center Magnetar, PSR J1745-2900', Astrophysical Journal Letters, vol. 852, no. 1, L12. https://doi.org/10.3847/2041-8213/aaa2f8

TY - JOUR

T1 - Large Magneto-ionic Variations toward the Galactic Center Magnetar, PSR J1745-2900

AU - Desvignes, G.

AU - Eatough, R. P.

AU - Pen, U. L.

AU - Lee, K. J.

AU - Mao, S. A.

AU - Karuppusamy, R.

AU - Schnitzeler, D. H.F.M.

AU - Falcke, H.

AU - Kramer, M.

AU - Wucknitz, O.

AU - Spitler, L. G.

AU - Torne, P.

AU - Liu, K.

AU - Bower, G. C.

AU - Cognard, I.

AU - Lyne, A. G.

AU - Stappers, B. W.

PY - 2018

Y1 - 2018

N2 - Polarized radio emission from PSR J1745-2900 has already been used to investigate the strength of the magnetic field in the Galactic center (GC), close to Sagittarius A∗. Here we report how persistent radio emission from this magnetar, for over four years since its discovery, has revealed large changes in the observed Faraday rotation measure (RM), by up to 3500 rad m-2 (a 5% fractional change). From simultaneous analysis of the dispersion measure, we determine that these fluctuations are dominated by variations in either the projected magnetic field or the free electron content within the GC, along the changing line of sight to the rapidly moving magnetar. From a structure function analysis of RM variations, and a recent epoch of rapid change of RM, we determine a minimum scale of magneto-ionic fluctuations of size ∼2 au at the GC distance, inferring PSR J1745-2900 is just ∼0.1 pc behind an additional scattering screen.

AB - Polarized radio emission from PSR J1745-2900 has already been used to investigate the strength of the magnetic field in the Galactic center (GC), close to Sagittarius A∗. Here we report how persistent radio emission from this magnetar, for over four years since its discovery, has revealed large changes in the observed Faraday rotation measure (RM), by up to 3500 rad m-2 (a 5% fractional change). From simultaneous analysis of the dispersion measure, we determine that these fluctuations are dominated by variations in either the projected magnetic field or the free electron content within the GC, along the changing line of sight to the rapidly moving magnetar. From a structure function analysis of RM variations, and a recent epoch of rapid change of RM, we determine a minimum scale of magneto-ionic fluctuations of size ∼2 au at the GC distance, inferring PSR J1745-2900 is just ∼0.1 pc behind an additional scattering screen.

KW - Galaxy: center

KW - magnetic fields

KW - pulsars: individual (J1745-2900)

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DO - 10.3847/2041-8213/aaa2f8

M3 - Article

AN - SCOPUS:85040345484

SN - 2041-8205

VL - 852

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

IS - 1

M1 - L12

ER -

Large Magneto-ionic Variations toward the Galactic Center Magnetar, PSR J1745-2900

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Keywords

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