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

Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy

Corresponding author: C. Vignali, chris@astro.psu.edu

Received: 31 August 2001
Accepted: 29 October 2001

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 ≈210²⁴ cm^-2, while the MECS spectrum is reflection-dominated, with a prominent (–1.2 keV) iron Kα emission line. The source is detected at only the 5σ 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° 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 about 50 times the Galactic value is derived.