Disclosing the true nature of the Sy 2 galaxy NGC 3281: one more Compton-thick source

Abstract

We present the BeppoSAX broad-band X-ray spectrum of the Seyfert 2 galaxy NGC 3281. The source high-energy spectrum is characterized by the nuclear transmitted component, with an absorbing column density of about 2 10^24 cm^-2, while the MECS spectrum is reflection-dominated, with a prominent (EW about 0.5-1.2 keV) iron K_alpha emission line. The source is detected at only the 5 sigma significance level in the LECS band, because of the strong obscuration which hampers at low energies the direct view of the active nucleus harbored in NGC 3281. BeppoSAX results are consistent with the scenario where NGC 3281 is inclined more than 60 degrees with respect to the line-of-sight. Combining the N_H value obtained from the present X-ray analysis with the A_V measurement, a N_H/A_V about 50 times the Galactic value is derived.

7 pages, 5 figures included, accepted for publication by Astronomy & Astrophysics

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