SIMBAD references

We present the results of a near-infrared and X-ray study of the Seyfert 2 galaxy NGC 3281. Emission from the Seyfert nucleus is detected in both regions of the electromagnetic spectrum, allowing us to infer both the equivalent line of sight hydrogen column density, N_H=71.0^+11.3_–12.3x10²⁶ m^–2, and the extinction due to dust, A_V = 22±11 mag (90% confidence intervals). We infer a ratio of N_H/A_V that is an order of magnitude larger than that determined along lines of sight in the Milky Way and discuss possible interpretations. We consider the most plausible explanation to be a dense cloud in the foreground of both the X-ray and infrared-emitting regions that obscures the entire X-ray source but only a fraction of the much larger infrared source.