NGC 1365 hosts an X-ray obscured AGN known for both its variable absorption and its relativistic features in the reflection component. Recent simultaneous observations performed by XMM-Newton and NuSTAR caught the source in a rare, nearly unobscured state, revealing the presence of a warm absorber and a neutral, but low column density (∼1022 cm−2) absorber, usually not observable due to thicker layers along the line of sight. Here I propose a multi-layer structure of the circumnuclear medium which can explain all the observed absorption states of this source, and their variability properties. Remarkably, despite the spectral complexity due to this multi-component absorber, the relativistic reflection component (and hence the black hole spin) can be unambiguously measured through a time resolved spectroscopic analysis.
Absorption from a multi-layer circumnuclear medium and reflection from the accretion disc in NGC 1365 / Risaliti, G.. - In: ASTRONOMISCHE NACHRICHTEN. - ISSN 1521-3994. - ELETTRONICO. - 337:(2016), pp. 529-533. [10.1002/asna.201612342]
Absorption from a multi-layer circumnuclear medium and reflection from the accretion disc in NGC 1365
RISALITI, GUIDO
2016
Abstract
NGC 1365 hosts an X-ray obscured AGN known for both its variable absorption and its relativistic features in the reflection component. Recent simultaneous observations performed by XMM-Newton and NuSTAR caught the source in a rare, nearly unobscured state, revealing the presence of a warm absorber and a neutral, but low column density (∼1022 cm−2) absorber, usually not observable due to thicker layers along the line of sight. Here I propose a multi-layer structure of the circumnuclear medium which can explain all the observed absorption states of this source, and their variability properties. Remarkably, despite the spectral complexity due to this multi-component absorber, the relativistic reflection component (and hence the black hole spin) can be unambiguously measured through a time resolved spectroscopic analysis.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.