2006/10/31 by F. Camilo, I. Cognard, S. M. Ransom +11 · 130 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Flux (metallurgy) #High-pressure geophysics and materials #Magnetar #Materials science #Neutron star #Observatory #Optics #Physics #Pulsar #Pulsars and Gravitational Waves Research #Pulse (music) #Radio telescope #Torque #X-ray pulsar #astro-ph
paper · pdf · doi:10.1086/518226
published in The Astrophysical Journal 663(1), 497-504 (IOP Publishing) · Accepted for publication in ApJ. Major changes with respect to submitted (v1) version: includes an additional 4 months of timing, flux and pulse shape data, and revised discussion
arxiv created 2007/03/19 · openalex publication_date 2007/06/22 · arxiv updated 2011/02/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report on observations of the radio-emitting anomalous X-ray pulsar XTE J1810-197 during 2006 May-October using the Nancay, Parkes, GBT, and VLA telescopes at a frequency of 1.4 GHz. The torque experienced by the neutron star during this period, as inferred from a measurement of its rotational frequency derivative, decreased by 30%, although not in a steady manner. We have also observed very large ongoing fluctuations in flux density and pulse shape. Superimposed on these, a general diminution of flux density and a broadening of the pulse profile components occurred nearly contemporaneously with a decrease in torque of about 10% that took place in late July over an interval of two weeks. In addition, a simultaneous observation of the pulsar with the Chandra X-ray Observatory and the GBT allows us to show how the X-ray and radio profiles are aligned. We discuss briefly the implications of these results for the magnetospheric currents in this remarkable object.