Spin frequency evolution and pulse profile variations of the recently re-activated radio magnetar XTE J1810-197. (arXiv:1903.02660v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Levin_L/0/1/0/all/0/1">L. Levin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lyne_A/0/1/0/all/0/1">A. G. Lyne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Desvignes_G/0/1/0/all/0/1">G. Desvignes</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eatough_R/0/1/0/all/0/1">R. P. Eatough</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Karuppusamy_R/0/1/0/all/0/1">R. Karuppusamy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kramer_M/0/1/0/all/0/1">M. Kramer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stappers_B/0/1/0/all/0/1">B. W. Stappers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weltevrede_P/0/1/0/all/0/1">P. Weltevrede</a>
After spending almost a decade in a radio-quiet state, the Anomalous X-ray
Pulsar XTE J1810-197 turned back on in early December 2018. We have observed
this radio magnetar at 1.5 GHz with ~daily cadence since the first detection of
radio re-activation on 8 December 2018. In this paper, we report on the current
timing properties of XTE J1810-197 and find that the magnitude of the spin
frequency derivative has increased by a factor of 2.6 over our 48-day data set.
We compare our results with the spin-down evolution reported during its
previous active phase in the radio band. We also present total intensity pulse
profiles at five different observing frequencies between 1.5 and 8.4 GHz,
collected with the Lovell and the Effelsberg telescopes. The profile evolution
in our data set is less erratic than what was reported during the previous
active phase, and can be seen varying smoothly between observations. Profiles
observed immediately after the outburst show the presence of at least five
cycles of a very stable ~50-ms oscillation in the main pulse component that
lasts for at least tens of days. This remarkable structure is seen across the
full range of observing frequencies.
After spending almost a decade in a radio-quiet state, the Anomalous X-ray
Pulsar XTE J1810-197 turned back on in early December 2018. We have observed
this radio magnetar at 1.5 GHz with ~daily cadence since the first detection of
radio re-activation on 8 December 2018. In this paper, we report on the current
timing properties of XTE J1810-197 and find that the magnitude of the spin
frequency derivative has increased by a factor of 2.6 over our 48-day data set.
We compare our results with the spin-down evolution reported during its
previous active phase in the radio band. We also present total intensity pulse
profiles at five different observing frequencies between 1.5 and 8.4 GHz,
collected with the Lovell and the Effelsberg telescopes. The profile evolution
in our data set is less erratic than what was reported during the previous
active phase, and can be seen varying smoothly between observations. Profiles
observed immediately after the outburst show the presence of at least five
cycles of a very stable ~50-ms oscillation in the main pulse component that
lasts for at least tens of days. This remarkable structure is seen across the
full range of observing frequencies.
http://arxiv.org/icons/sfx.gif
