TUNA Lunch Talk:

Avanti Tilak

Harvard-Smithsonian CfA,

A Deep 0.3-10 keV Spectrum of the H2O Maser Galaxy IC 2560

December 11

12:10PM, Note unusual location: Room 311 , NRAO, Edgemont Road


I present a spectrum of an XMM-Newton observation of the 22 GHz water maser source IC 2560. The X-ray spectrum shows soft excess due to multi-temperature ionized plasma, a hard continuum and strong emission features, from Mg, Si, S, Ca, Fe and Ni, mainly due to fluorescence. The spectrum is consistent with reflection from a mostly neutral medium and obscuration due to a very high column density, greater than 1024 cm-2. The spectrum also shows a warm scattered component of the unobscured emission as well as an emission line at 6.7 keV, possibly due to FeXXV, undetected in previous Chandra observations. The absorption column density for the FeXXV line is less than 1023 cm-2 s-1, which is much lower than the obscuration of the central source. I compare X-ray and maser emission characteristics of IC 2560 and other AGN that exhibit water maser emission originating in disk structures around central engines. We find that the measured minimum disk radii of maser emission and the clumpiness of disk structures (inferred from the distribution of maser emission) appear to depend on the unobscured luminosities of central engines.