The Nuclear X-Ray Emission-line Structure in NGC 2992 Revealed by Chandra-HETGS

We present the narrow emission-line structure revealed by a 135 ks Chandra observation of Seyfert galaxy NGC 2992, using the High Energy Transmission Grating Spectrometer. The source was observed in an historically low-flux state. Using a Bayesian Block search technique, we detected neutral Si K alpha and Si K alpha fluorescence and two additional lines that are consistent with redshifted, ionized Si emission. The latter two features are indicative of a photoionized outflow with a velocity of similar to 2500 km s(-1). We also observed prominent, unresolved line emission at the rest energy of Fe. Ka, with a 90% confidence FWHM velocity width of <2000 km s(-1) (<2800 km s(-1)) and equivalent width of 406-1148 eV (288-858 eV) when broad Fe. Ka line emission, as detected by Suzaku, was (was not) included in the model.