Accurate X-ray position and multiwavelength observations of the isolated neutron star RBS 1774

Abstract

We report on X-ray, optical, infrared and radio observations of the isolated neutron star 1RXS J214303.7+065419 (RBS 1774). The X-ray observation was performed with the high-resolution camera onboard the Chandra X-ray Observatory, allowing us to derive the most accurate position for this source (; 90 per cent uncertainty of 0.6 arcsec). Furthermore, we confirmed with a higher spatial accuracy the point-like nature of this X-ray source. Observations were taken in B, V, r′, i′, J, H and Ks filters using the Keck, Very Large Telescope (VLT), Blanco and Magellan telescopes, while radio observations were obtained from the Parkes single dish at 2.9 GHz and 708 MHz. No plausible optical and/or infrared counterpart for RBS 1774 was detected within the refined sub-arsecond Chandra X-ray error circle. Present upper limits to the optical and the infrared magnitudes are r′ > 25.7 and J > 22.6 (5σ confidence level). Radio observations did not show evidence for radio pulsations down to a luminosity at 1.4 GHz of L < 0.02 mJy kpc2. Furthermore, no convincing evidence for Rotating Radio Transients-like radio bursts has been found. Our results on RBS 1774 are discussed and compared with the known properties of other thermally emitting neutron stars.