PULSE BROADENING MEASUREMENTS FROM THE GALACTIC CENTER PULSAR J1745-2900

Journal Article · Wed Jan 01 04:00:00 EST 2014 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/780/1/L3· OSTI ID:22364070

Spitler, L. G.; Lee, K. J.; Eatough, R. P.; Kramer, M.; Karuppusamy, R.; Desvignes, G.; Champion, D. J.; Falcke, H. ^[1]; Bassa, C. G.; Lyne, A. G.; Stappers, B. W. ^[2]; Cognard, I. ^[3]; Bower, G. C. ^[4]; Cordes, J. M. ^[5]

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1. Max-Planck-Institut für Radioastronomie, Bonn D-53121 (Germany)
2. Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, M13, 9PL Manchester (United Kingdom)
3. Laboratoire de Physique et Chimie de l'Environnement et de l'Espace LPC2E CNRS-Université d'Orléans, F-45071 Orléans Cedex 02, and Station de radioastronomie de Nançay, Observatoire de Paris, CNRS/INSU, F-18330 Nançay (France)
4. UC Berkeley Astronomy Department, B-20 Hearst Field Annex, Berkeley, CA 94720-3411 (United States)
5. Department of Astronomy and Space Sciences, Cornell University, Ithaca, NY 14853 (United States)

We present temporal scattering measurements of single pulses and average profiles of PSR J1745-2900, a magnetar recently discovered only 3 arcsec away from Sagittarius A* (Sgr A*), from 1.2 to 18.95 GHz using the Effelsberg 100 m Radio Telescope, the Nançay Decimetric Radio Telescope, and the Jodrell Bank Lovell Telescope. Single pulse analysis shows that the integrated pulse profile above 2 GHz is dominated by pulse jitter, while below 2 GHz the pulse profile shape is dominated by scattering. This is the first object in the Galactic center (GC) with both pulse broadening and angular broadening measurements. We measure a pulse broadening time scale at 1 GHz of τ{sub 1GHz} = 1.3 ± 0.2 and pulse broadening spectral index of α = –3.8 ± 0.2, which is several orders of magnitude lower than predicted by the NE2001 model (Cordes and Lazio 2002). If this scattering time scale is representative of the GC as a whole, then previous surveys should have detected many pulsars. The lack of detections implies either our understanding of scattering in the GC is incomplete or there are fewer pulsars in the GC than previously predicted. Given that magnetars are a rare class of radio pulsar, there are likely many canonical and millisecond pulsars in the GC, and not surprisingly, scattering in the GC is spatially complex.

• OSTI ID: 22364070
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 780; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
DETECTION
GHZ RANGE
INDEXES
MAGNETIC STARS
MILKY WAY
PULSARS
PULSES
RADIO TELESCOPES
SCATTERING