The Nuclear Outflows and Feedback in the Seyfert 2 Galaxy Markarian 573

TL;DR

This study uses high-resolution HST spectroscopy to analyze the nuclear outflows in Seyfert 2 galaxy Markarian 573, finding that the outflows are weak and unlikely to significantly influence galaxy evolution.

Contribution

It provides detailed kinematic and ionization analysis of nuclear outflows in Markarian 573, challenging the notion of strong AGN feedback in galaxy evolution.

Findings

Outflows do not significantly accelerate surrounding gas.

Outflows are too weak to be a major ionization source.

Energy in outflows is insufficient to disrupt star formation.

Abstract

We present a study of outflow and feedback in the well-known Seyfert 2 galaxy Markarian 573 using high angular resolution long-slit spectrophotometry obtained with the Hubble Space Telescope Imaging Spectrograph (STIS). Through analysis of the kinematics and ionization state of a biconical outflow region emanating from the nucleus, we find that the outflow does not significantly accelerate the surrounding host-galaxy interstellar gas and is too weak to be a strong ionization mechanism in the extended emission regions. Instead, the excitation of the extended regions is consistent with photoionization by the active nucleus. From energetics arguments we show that the nuclear outflow is slow and heavy and has a mechanical luminosity that is only ~1% of the estimated bolometric luminosity of the system. The energy in the outflow is able to mildly shape the gas in the extended regions but appears to be insufficient to unbind it, or even to plausibly disrupt star formation. These results are at odds with the picture of strong AGN feedback that has been invoked to explain certain aspects of galaxy evolution.