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Changing-look event in NGC 3516: continuum or obscuration variability?
Missagh Mehdipour, Gerard A. Kriss, Laura W. Brenneman +6
The Seyfert-1 galaxy NGC 3516 has undergone major spectral changes in recent years. In 2017 we obtained Chandra, NuSTAR, and Swift observations during its new low-flux state. Using…
Transient obscuration event captured in NGC~3227 II. Warm absorbers and obscuration events in archival XMM-Newton and NuSTAR observations
Yijun Wang, Jelle Kaastra, Missagh Mehdipour +18
The relation between warm absorber (WA) outflows of AGN and nuclear obscuration activities caused by optically-thick clouds (obscurers) crossing the line of sight is unclear. NGC 3…
Multi-epoch properties of the warm absorber in the Seyfert 1 galaxy NGC 985
J. Ebrero, V. Domcek, G. A. Kriss +1
(Abridged) NGC 985 was observed by XMM-Newton twice in 2015, revealing that the source was coming out from a soft X-ray obscuration event that took place in 2013. These kinds of ev…
Transient obscuration event captured in NGC 3227. I. Continuum model for the broadband spectral energy distribution
M. Mehdipour, G. A. Kriss, J. S. Kaastra +21
From Swift monitoring of a sample of active galactic nuclei (AGN) we found a transient X-ray obscuration event in Seyfert-1 galaxy NGC 3227, and thus triggered our joint XMM-Newton…