SIMBAD references

Using a subpixel event repositioning technique, we spatially resolved X-ray emission from the infrared double system IRS 5 in the R Corona Australis molecular cloud with ∼0.8" separation. As far as we know, this result–obtained from eight Chandra archival observations between 2000 and 2005–is the first X-ray study of individual sources in a Class I protostar binary system with a projected separation of less than 200 AU. We extracted light curves and spectra of the individual sources using a two-dimensional image-fitting method. IRS 5a at the south, the source that was brighter in the near-infrared, showed three X-ray flares lasting >20 ks, reminiscent of X-ray flares from pre-main-sequence stars, while the northern source (IRS 5b) was quiescent in X-rays in all the observations except for a 2005 August 9 observation with a factor of ∼2 flux enhancement. In quiescence, these sources showed almost identical X-ray spectra, with N_H∼4x10²²/cm2, kT∼2 keV, and logL_X∼30.2-30.3 ergs/s. IRS 5a showed plasma at temperatures up to kT∼5-6 keV during flares, while the column density of IRS 5b increased by a factor of 2 during an observation on 2005 August 9. We discuss the evolutionary stages and variation of the X-ray activity of these sources.