656 research outputs found
A Deep Infrared Search for AXP 1E 1841-045
Multi-colour (JHKs) imaging and photometry of the field of the Anomalous
X-ray Pulsar AXP 1E 1841-045 is analysed in the light of new, accurate
coordinates from Chandra (Wachter et al, 2004). From excellentquality images,
we find multiple sources in and around the position error circle. Of these,
none can be confidently identified as the infrared counterpart. The limiting
magnitudes reached were J=22.1, H=20.7 and Ks=19.9$ (95% confidence).Comment: 8 pages LaTeX, 2 eps figures; ApJ accepte
The infrared counterpart to the magnetar 1RXS J170849.0-400910
We have analyzed both archival and new infrared imaging observations of the
field of the Anomalous X-ray Pulsar 1RXS J170849.0-400910, in search of the
infrared counterpart. This field has been previously investigated, and one of
the sources consistent with the position of the AXP suggested as the
counterpart. We, however, find that this object is more likely a background
star, while another object within the positional error circle has non-stellar
colors and shows evidence for variability. These two pieces of evidence, along
with a consistency argument for the X-ray-to-infrared flux ratio, point to the
second source being the more likely infrared counterpart to the AXP.Comment: 19 pages AASTEX, 4 figure. Accepted for publication in ApJ. Full
resolution figures at: http://www.astro.utoronto.ca/~durant/1708.ps.g
The Broad-Band Spectrum and Infrared Variability of the Magnetar AXP 1E1048.1-5937
We present photometry of the Anomalous X-ray pulsar 1E1048.1-5937 in the
infrared and optical, taken at Magellan and the VLT. The object is detected in
the I, J and Ks bands under excellent conditions. We find that the source has
varied greatly in its infrared brightness and present these new magnitudes. No
correlation is found between the infrared flux and spin-down rate, but the
infrared flux and X-ray flux may be anti-correlated. Assuming nominal reddening
values, the resultant spectral energy distribution is found to be inconsistent
with the only other AXP SED available (for 4U0142+61). We consider the effect
of the uncertainty in the reddening to the source on its SED. We find that
although both the X-ray and infrared fluxes have varied greatly for this
source, the most recent flux ratio is remarkably consistent with what is is
found for other AXPs. Finally, we discuss the implications of our findings in
the context of the magnetar model.Comment: 21 pages, 5 eps figures. Submitted to Ap
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