AGN-Driven Outflows in Dwarf Galaxies. (arXiv:1905.09287v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Manzano_King_C/0/1/0/all/0/1">Christina Manzano-King</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Canalizo_G/0/1/0/all/0/1">Gabriela Canalizo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sales_L/0/1/0/all/0/1">Laura Sales</a>
We present spatially resolved kinematic measurements of AGN-driven outflows
in dwarf galaxies in the stellar mass range $5.89times10^8 – 9.33times10^9
M_{odot}$, selected from SDSS DR7,8 and followed up with Keck/LRIS
spectroscopy. From a parent sample of 50 dwarf galaxies with and without AGN,
we find spatially extended (up to $sim 1.5,rm{kpc}$), high velocity ionized
gas outflows ($W_{80}$ up to $sim2000,rm{km,s}^{-1}$) in 13 dwarf galaxies.
Nine of the galaxies with outflows have optical line ratios indicative of AGN,
and six of these have outflow components with optical line ratios also
consistent with AGN ionization. Outflow velocities in all 13 galaxies exceed
the escape velocities of their halos. Although black holes have been known to
populate the centers of (at least a few) dwarf galaxies, and indirect evidence
of AGN quenching of star formation in dwarfs has begun to surface, our
measurements constitute the first direct detection and measurement of AGN
impact on the large scale kinematics and gas content in dwarf galaxies.
Furthermore, we find evidence suggestive of ongoing star formation suppression,
possibly regulated by the AGN. Galaxy formation models must therefore be able
to account not only for the formation and growth of black holes at the centers
of dwarf galaxies, but should also be revised to include AGN as important —
and perhaps dominant — sources of feedback in low mass galaxies.
We present spatially resolved kinematic measurements of AGN-driven outflows
in dwarf galaxies in the stellar mass range $5.89times10^8 – 9.33times10^9
M_{odot}$, selected from SDSS DR7,8 and followed up with Keck/LRIS
spectroscopy. From a parent sample of 50 dwarf galaxies with and without AGN,
we find spatially extended (up to $sim 1.5,rm{kpc}$), high velocity ionized
gas outflows ($W_{80}$ up to $sim2000,rm{km,s}^{-1}$) in 13 dwarf galaxies.
Nine of the galaxies with outflows have optical line ratios indicative of AGN,
and six of these have outflow components with optical line ratios also
consistent with AGN ionization. Outflow velocities in all 13 galaxies exceed
the escape velocities of their halos. Although black holes have been known to
populate the centers of (at least a few) dwarf galaxies, and indirect evidence
of AGN quenching of star formation in dwarfs has begun to surface, our
measurements constitute the first direct detection and measurement of AGN
impact on the large scale kinematics and gas content in dwarf galaxies.
Furthermore, we find evidence suggestive of ongoing star formation suppression,
possibly regulated by the AGN. Galaxy formation models must therefore be able
to account not only for the formation and growth of black holes at the centers
of dwarf galaxies, but should also be revised to include AGN as important —
and perhaps dominant — sources of feedback in low mass galaxies.
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