High mass X-ray binaries in the LMC: Dependence on the stellar population age and the propeller effect

We study the population of compact X-ray sources in the Large Magellanic Cloud using the archival data of the XMM-Newton observatory. The total area of the survey is approximate to 3.8 square degrees with a limiting sensitivity of approximate to 10(-14) erg/s/cm(2), corresponding to a luminosity of approximate to 3 x 10(33) erg/s at the LMC distance. Out of similar to 460 point sources detected in the 2 - 8 keV energy band, the vast majority are background CXB sources, observed through the LMC. Based on the properties of the optical and near-infrared counterparts of the detected sources we identified 9 likely HMXB candidates and 19 sources, whose nature is uncertain, thus providing lower and upper limits on the luminosity distribution of HMXBs in the observed part of LMC. When considered globally, the bright end of this distribution is consistent within statistical and systematic uncertainties with extrapolation of the universal luminosity function of HMXBs. However, there seems to be fewer low luminosity sources, log(L-X) less than or similar to 35.5, than predicted. We consider the impact of the propeller effect on the HMXB luminosity distribution and show that it can qualitatively explain the observed deficit of low luminosity sources. We found significant field-to-field variations in the number of HMXBs across the LMC, which appear to be uncorrelated with the star formation rates inferred by the FIR and H-alpha emission. We suggest that these variations are caused by the dependence of the HMXB number on the age of the underlying stellar population. Using the existence of large coeval stellar aggregates in the LMC, we constrain the number of HMXBs as a function of time tau elapsed since the star formation event in the range of tau from similar to 1- 2 Myr to similar to 10-12 Myr.