We introduce the first galaxy–Ovi absorption kinematic study for 20 absorption systems (EW > 0.1 Å) associated with isolated galaxies (0.15 ≤ z ≤ 0.55) that have accurate redshifts and rotation curves obtained using Keck/ESI. Our sample is split into two azimuthal angle bins: major axis (Φ < 25°) and minor axis (Φ > 33°). O vi absorption along the galaxy major axis is not correlated with galaxy rotation kinematics, with only 1/10 of systems that could be explained with rotation/accretion models. This is in contrast to corotation commonly observed for Mg ii absorption. Ovi along the minor axis could be modeled by accelerating outflows, but only for small opening angles, while the majority of the Ovi is decelerating. Along both axes, stacked Ovi profiles reside at the galaxy systemic velocity with the absorption kinematics spanning the entire dynamical range of their galaxies. The Ovi found in AMR cosmological simulations exists within filaments and in halos of ~50 kpc surrounding galaxies. Simulations show that major-axis Ovi gas inflows along filaments and decelerates as it approaches the galaxy, while increasing in its level of corotation. Minor-axis outflows in the simulations are effective within 50–75 kpc; beyond that they decelerate and fall back onto the galaxy. While the simulations show clear Ovi kinematic signatures, they are not directly comparable to observations. When we compare kinematic signatures integrated through the entire simulated galaxy halo, we find that these signatures are washed out owing to full velocity distribution of Ovi throughout the halo. We illustrate that Ovi alone does not serve as a useful kinematic indicator of gas accretion, outflows, or star formation and likely best probes the halo virial temperature.
Kacprzak, Glenn G., et al. "The Relation between Galaxy ISM and Circumgalactic O<sub>vi</sub> Gas Kinematics Derived from Observations and ΛCDM Simulations." The Astrophysical Journal (Online), vol. 870, no. 2, Jan. 2019. https://doi.org/10.3847/1538-4357/aaf1a6
Kacprzak, Glenn G., Vander Vliet, Jacob R., Nielsen, Nikole M., Muzahid, Sowgat, Pointon, Stephanie K., Churchill, Christopher W., Ceverino, Daniel, Arraki, Kenz S., Klypin, Anatoly, Charlton, Jane C., & Lewis, James (2019). The Relation between Galaxy ISM and Circumgalactic O<sub>vi</sub> Gas Kinematics Derived from Observations and ΛCDM Simulations. The Astrophysical Journal (Online), 870(2). https://doi.org/10.3847/1538-4357/aaf1a6
Kacprzak, Glenn G., Vander Vliet, Jacob R., Nielsen, Nikole M., et al., "The Relation between Galaxy ISM and Circumgalactic O<sub>vi</sub> Gas Kinematics Derived from Observations and ΛCDM Simulations," The Astrophysical Journal (Online) 870, no. 2 (2019), https://doi.org/10.3847/1538-4357/aaf1a6
@article{osti_1544076,
author = {Kacprzak, Glenn G. and Vander Vliet, Jacob R. and Nielsen, Nikole M. and Muzahid, Sowgat and Pointon, Stephanie K. and Churchill, Christopher W. and Ceverino, Daniel and Arraki, Kenz S. and Klypin, Anatoly and Charlton, Jane C. and others},
title = {The Relation between Galaxy ISM and Circumgalactic O<sub>vi</sub> Gas Kinematics Derived from Observations and ΛCDM Simulations},
annote = {We introduce the first galaxy–Ovi absorption kinematic study for 20 absorption systems (EW > 0.1 Å) associated with isolated galaxies (0.15 ≤ z ≤ 0.55) that have accurate redshifts and rotation curves obtained using Keck/ESI. Our sample is split into two azimuthal angle bins: major axis (Φ 33°). O vi absorption along the galaxy major axis is not correlated with galaxy rotation kinematics, with only 1/10 of systems that could be explained with rotation/accretion models. This is in contrast to corotation commonly observed for Mg ii absorption. Ovi along the minor axis could be modeled by accelerating outflows, but only for small opening angles, while the majority of the Ovi is decelerating. Along both axes, stacked Ovi profiles reside at the galaxy systemic velocity with the absorption kinematics spanning the entire dynamical range of their galaxies. The Ovi found in AMR cosmological simulations exists within filaments and in halos of ~50 kpc surrounding galaxies. Simulations show that major-axis Ovi gas inflows along filaments and decelerates as it approaches the galaxy, while increasing in its level of corotation. Minor-axis outflows in the simulations are effective within 50–75 kpc; beyond that they decelerate and fall back onto the galaxy. While the simulations show clear Ovi kinematic signatures, they are not directly comparable to observations. When we compare kinematic signatures integrated through the entire simulated galaxy halo, we find that these signatures are washed out owing to full velocity distribution of Ovi throughout the halo. We illustrate that Ovi alone does not serve as a useful kinematic indicator of gas accretion, outflows, or star formation and likely best probes the halo virial temperature.},
doi = {10.3847/1538-4357/aaf1a6},
url = {https://www.osti.gov/biblio/1544076},
journal = {The Astrophysical Journal (Online)},
issn = {ISSN 1538-4357},
number = {2},
volume = {870},
place = {United States},
publisher = {Institute of Physics (IOP)},
year = {2019},
month = {01}}