The Changing-Look Quasar Mrk 590 is Awakening
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Mrk 590 was originally classified as a Seyfert 1 galaxy, but then it
underwent dramatic changes: the nuclear luminosity dropped by over two
orders of magnitude and the broad emission lines all but disappeared
from the optical spectrum. Here we present followup observations to the
original discovery and characterization of this "changing look" active
galactic nucleus (AGN). The new Chandra and HST observations from 2014
show that Mrk 590 is awakening, changing its appearance again. While the
source continues to be in a low state, its soft excess has re-emerged,
though not to the previous level. The UV continuum is brighter by more
than a factor of two and the broad MgII emission line is present,
indicating that the ionizing continuum is also brightening. These
observations suggest that the soft excess is not due to reprocessed hard
X-ray emission. Instead, it is connected to the UV continuum through
warm Comptonization. Variability of the Fe K-alpha emission lines
suggests that the reprocessing region is within about 10 light years or
3 pc of the central source. The AGN type change is neither due to
obscuration, nor due to one-way evolution from type-1 to type-2, as
suggested in literature, but may be related to episodic accretion
events.
Originalsprog | Engelsk |
---|---|
Artikelnummer | 123 |
Tidsskrift | Astrophysical Journal |
Vol/bind | 866 |
Udgave nummer | 2 |
Antal sider | 5 |
ISSN | 0004-637X |
DOI | |
Status | Udgivet - 20 okt. 2018 |
Links
- https://arxiv.org/pdf/1810.06616.pdf
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