  Swift observed an outburst from the supergiant fast X-ray transients (SFXT)
AX J1841.0-0536 on 2010 June 5, and followed it with XRT for 11 days. The X-ray
light curve shows an initial flare followed by a decay and subsequent increase,
as often seen in other SFXTs, and a dynamical range of ~1600. Our observations
allow us to analyse the simultaneous broad-band (0.3-100 keV) spectrum of this
source, for the first time down to 0.3 keV, can be fitted well with models
usually adopted to describe the emission from accreting neutron stars in
high-mass X-ray binaries, and is characterized by a high absorption
(N_H~2x10^22 cm-2), a flat power law (Gamma~0.2), and a high energy cutoff. All
of these properties resemble those of the prototype of the class, IGR
J17544-2619, which underwent an outburst on 2010 March 4, whose observations we
also discuss. We show how well AX J1841.0-0536 fits in the SFXT class, based on
its observed properties during the 2010 outburst, its large dynamical range in
X-ray luminosity, the similarity of the light curve (length and shape) to those
of the other SFXTs observed by Swift, and the X-ray broad-band spectral
properties.
