A Curved 150 Parsec Long Jet in the Double-Peaked Emission-Line AGN KISSR 434. (arXiv:1812.11074v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Kharb_P/0/1/0/all/0/1">Preeti Kharb</a> (NCRA-TIFR), <a href="http://arxiv.org/find/astro-ph/1/au:+Vaddi_S/0/1/0/all/0/1">Sravani Vaddi</a> (NCRA-TIFR), <a href="http://arxiv.org/find/astro-ph/1/au:+Sebastian_B/0/1/0/all/0/1">Biny Sebastian</a> (NCRA-TIFR), <a href="http://arxiv.org/find/astro-ph/1/au:+Subramanian_S/0/1/0/all/0/1">Smitha Subramanian</a> (IIA), <a href="http://arxiv.org/find/astro-ph/1/au:+Das_M/0/1/0/all/0/1">Mousumi Das</a> (IIA), <a href="http://arxiv.org/find/astro-ph/1/au:+Paragi_Z/0/1/0/all/0/1">Zsolt Paragi</a> (JIVE)

Double-peaked emission lines in the narrow- and/or broad-line spectra of AGN
have been suggested to arise due to disky broad/narrow line regions, jet-medium
interaction, or the presence of binary supermassive black holes. We present the
results from 1.5 and 4.9 GHz phase-referenced Very Long Baseline Interferometry
(VLBI) observations of the Seyfert type 2 galaxy KISSR 434, which exhibits
double-peaked emission lines in its optical spectrum. We detect a
steep-spectrum ($alpha<-1$), curved and long (~150 parsec) jet in the VLBI images of KISSR 434. The jet curvature could be a result of precession rather than ram-pressure bending from a rotating ISM. Precession could in turn arise due to a warped accretion disk or the presence of a binary black hole with a separation of 0.015 parsec, not accessible to present day telescopes. An examination of the emission line ratios with the MAPPINGS III code reveals that AGN photoionization is likely to be responsible for the observed line ratios and not shock-ionization due to the jet. A light (with jet-to-ambient medium density ratio of $etasim0.01$) and fast (with speed $v_jgtrsim0.75c$) precessing jet in KISSR 434 may have stirred up the emission-line gas clouds to produce the observed splits in the narrow line peaks but is not powerful enough to shock-ionise the gas.

Double-peaked emission lines in the narrow- and/or broad-line spectra of AGN
have been suggested to arise due to disky broad/narrow line regions, jet-medium
interaction, or the presence of binary supermassive black holes. We present the
results from 1.5 and 4.9 GHz phase-referenced Very Long Baseline Interferometry
(VLBI) observations of the Seyfert type 2 galaxy KISSR 434, which exhibits
double-peaked emission lines in its optical spectrum. We detect a
steep-spectrum ($alpha<-1$), curved and long (~150 parsec) jet in the VLBI
images of KISSR 434. The jet curvature could be a result of precession rather
than ram-pressure bending from a rotating ISM. Precession could in turn arise
due to a warped accretion disk or the presence of a binary black hole with a
separation of 0.015 parsec, not accessible to present day telescopes. An
examination of the emission line ratios with the MAPPINGS III code reveals that
AGN photoionization is likely to be responsible for the observed line ratios
and not shock-ionization due to the jet. A light (with jet-to-ambient medium
density ratio of $etasim0.01$) and fast (with speed $v_jgtrsim0.75c$)
precessing jet in KISSR 434 may have stirred up the emission-line gas clouds to
produce the observed splits in the narrow line peaks but is not powerful enough
to shock-ionise the gas.

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