Subarcsecond location of IGR J17480-2446 with Rossi XTE

TL;DR

This paper demonstrates a novel technique using lunar occultation observed by Rossi XTE to determine the position of an X-ray source with subarcsecond accuracy, surpassing the instrument's imaging limitations.

Contribution

It introduces a new method for precise X-ray source localization using lunar occultation data from non-imaging observatories.

Findings

Achieved 40 mas positional accuracy for IGR J17480-2446.

First subarcsecond localization of an X-ray source with a non-imaging satellite.

Shows potential for applying this technique to future X-ray missions.

Abstract

On 2010 October 13, the X-ray astronomical satellite Rossi XTE, during the observation of the newly discovered accretion powered X-ray pulsar IGR J17480--2446, detected a lunar occultation of the source. From knowledge of lunar topography and Earth, Moon, and spacecraft ephemeris at the epoch of the event, we determined the source position with an accuracy of 40 mas (1{\sigma} c.l.), which is interesting, given the very poor imaging capabilities of RXTE (\sim 1\circ). For the first time, using a non-imaging X-ray observatory, the position of an X-ray source with a subarcsecond accuracy is derived, demonstrating the neat capabilities of a technique that can be fruitfully applied to current and future X-ray missions.