SUPPORTED In the last decade it has become clear that there exists a small subset of pulsars that are powered neither by rotation nor accretion but by the decay of their enormous magnetic fields -- magnetars. The origin of the X-ray emission from magnetar-candidate AXPs (Anomalous X-ray Pulsars) is fairly well understood within the framework of the magnetar model. However, where and how the optical/IR emission is produced is unclear. If, as recent models suggest, the optical/IR emission is magnetospheric, then any variation in the optical/IR flux should be accompanied by variation in the X-ray spectra. We therefore propose for joint Chandra-Hubble observations of two magnetar candidates in order to test the optical/IR emission models for magnetars.

We plan to observe one target 4 times with HST/NICMOS simultaneously with Chandra, using the nic 3 camera and the f160w and f110w filters. On visits 1 and 2, we use the nic spiral dither pattern with 30 points, spaced 5 arcseconds apart. In filter f160w, exposures will be made in multiaccum mode with for an integration time of 39.9 seconds per pointing, or 1197 seconds total. The 30-point pattern and 2 sets of exposures fill 2 orbit per visit; thus, visits 1 and 2 will require a total of 4 orbits. On visits 3 and 4, we use a similar nic spiral dither pattern, but with 26 points spaced 5 arcseconds apart. Only filter f160w is used, with the same multiaccum settings as above for a total integration time of 1037 seconds. Visits 3 and 4 are each one complete orbit. Our scientific goal is to monitor IR flux changes in our target, and search for correlations with X-ray spectral variability. In order to identify variability that is truly correlated, we require that our HST and Chandra observations be simultaneous, or at least overlapping in time. Ideally, the visits would be separated by approximately greater than 2 months and equispaced. STAR NEUTRON STAR PULSAR J2000 H~22 mag, J=23.4 mag 1 NIC-SPIRAL-DITH SPIRAL DITHER 30 5.0 POS-TARG 0.0 false false 2 NIC-SPIRAL-DITH SPIRAL DITHER 26 5.0 POS-TARG 0.0 false false This visit must be scheduled simultaneously with Chandra. This visit must be scheduled simultaneously with Chandra. This visit must be scheduled simultaneously with Chandra. This visit must be scheduled simultaneously with Chandra.