We analyse RXTE and Swift observations of SWIFT J1729.9 - 3437 after its outburst from 2010 July 20 to 2010 August 12 .
We calculate a spin frequency and spin frequency derivative of 1.8734 ( 8 ) \times 10 ^ { -3 } Hz and 6.42 ( 6 ) \times 10 ^ { -12 } Hz/s respectively from the quadratic fit of the pulse arrival times.The quadratic fit residuals fit well to a circular orbital model with a period of 15.3 ( 2 ) days and a mass function of about 1.3 M _ { \odot } , but they can also be explained by a torque noise strength of 6.8 \times 10 ^ { -18 } Hz sec ^ { -2 } .
Pulse profiles switch from double-peaked to single-peaked as the source flux continues to decrease .
We find that the pulse shape generally shows no strong energy dependence .
The hardness ratios reveal that the source becomes softer with decreasing flux .
We construct a single spectrum from all the available RXTE and Swift observations .
We find that adding an Fe line complex feature around 6.51 keV slightly improves the spectral fit .
We also find that Fe line flux correlates with X-ray flux which might indicate the origin of the Fe emission as the source itself rather than the Galactic ridge .