In:
The Astrophysical Journal, American Astronomical Society, Vol. 886, No. 2 ( 2019-12-01), p. 145-
Abstract:
We present a flux-resolved X-ray analysis of the dwarf Seyfert 1.8 galaxy NGC 4395, based on three archival XMM-Newton and one archival NuSTAR observations. The source is known to harbor a low-mass black hole ( ) and shows strong variability in the full X-ray range during these observations. We model the flux-resolved spectra of the source assuming three absorbing layers: neutral, mildly ionized, and highly ionized ( , , and 3.8 × 10 22 cm −2 , respectively). The source also shows intrinsic variability by a factor of ∼3 on short timescales, which is due to changes in the nuclear flux, assumed to be a power law (Γ = 1.6–1.67). Our results show a positive correlation between the intrinsic flux and the absorbers’ ionization parameter. The covering fraction of the neutral absorber varies during the first XMM-Newton observation, which could explain the pronounced soft X-ray variability. However, the source remains fully covered by this layer during the other two observations, largely suppressing the soft X-ray variability. This suggests an inhomogeneous and layered structure in the broad-line region. We also find a difference in the characteristic timescale of the power spectra between different energy ranges and observations. We finally show simulated spectra with XRISM , eXTP , and Athena , which will allow us to characterize the different absorbers, study their dynamics, and will help us identify their locations and sizes.
Type of Medium:
Online Resource
ISSN:
0004-637X
,
1538-4357
DOI:
10.3847/1538-4357/ab5110
Language:
Unknown
Publisher:
American Astronomical Society
Publication Date:
2019
detail.hit.zdb_id:
2960-9
detail.hit.zdb_id:
1473835-1
SSG:
16,12
