XMM-NEWTON Observation of the Seyfert 2 Galaxy NGC 4138
Abstract
The XMM-Newton data presented here are the first X-ray observation of the Seyfert 2 galaxy NGC4138. Although the galaxy has been pointed by ROSAT-HRI, it was not detected, with a flux upper limit of about 1.1x10-13 erg cm-2 s-1 in the 0.2-2.4 keV energy band. XMM-Newton performed the observation on 26 November 2001. The source is detected for the first time in X-rays with F[0.2-2.4]=1.0x10-13 erg cm-2 s-1, in agreement with the upper limit of ROSAT. The source spectrum is typical of Seyfert 2 galaxies. We find heavy obscuration (NH about 8x1022 cm-2) and a flat photon index (1.6). The source intrinsic luminosity is about 5x1041 erg/s in the 0.5-10 keV energy band.
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