AX J1845–0258 is a transient X-ray pulsar , with spin period of 6.97s , discovered with the ASCA satellite in 1993 .
Its soft spectrum and the possible association with a supernova remnant suggest that AX J1845–0258 might be a magnetar , but this has not been confirmed yet .
A possible counterpart one order of magnitude fainter , AX J184453–025640 , has been found in later X-ray observations , but no pulsations have been detected .
In addition , some other X-ray sources are compatible with the pulsar location , which is in a crowded region of the Galactic plane .
We have carried out a new investigation of all the X-ray sources in the ASCA error region of AX J1845–0258 , using archival data obtained with Chandra in 2007 and 2010 , and with XMM-Newton in 2010 .
We set an upper limit of 6 % on the pulsed fraction of AX J184453–025640 and confirmed its rather hard spectrum ( power law photon index of 1.2 \pm 0.3 ) .
In addition to the other two fainter sources already reported in the literature , we found other X-ray sources positionally consistent with AX J1845–0258 .
Although many of them are possibly foreground stars likely unrelated to the pulsar , at least another new source , CXOU J184457.5–025823 , could be a plausible counterpart of AX J1845–0258 .
It has a flux of 6 \times 10 ^ { -14 } erg cm ^ { -2 } s ^ { -1 } and a spectrum well fit by a power law with photon index \sim 1.3 and N _ { \text { H } } \sim 10 ^ { 22 } cm ^ { -2 } .