Incidence, scaling relations and physical conditions of ionized gas outflows in MaNGA

Abstract

In this work, we investigate the strength and impact of ionised gas outflows within z ∼ 0.04 MaNGA galaxies. We find evidence for outflows in 322 galaxies ($12{{\ \rm per\ cent}}$ of the analysed line-emitting sample), 185 of which show evidence for AGN activity. Most outflows are centrally concentrated with a spatial extent that scales sublinearly with Re. The incidence of outflows is enhanced at higher masses, central surface densities and deeper gravitational potentials, as well as at higher SFR and AGN luminosity. We quantify strong correlations between mass outflow rates and the mechanical drivers of the outflow of the form $\dot{M}_{\rm out} \propto \rm SFR^{0.97}$ and $\dot{M}_{\rm out} \propto L_{\rm AGN}^{0.55}$. We derive a master scaling relation describing the mass outflow rate of ionised gas as a function of M⋆, SFR, Re and LAGN. Most of the observed winds are anticipated to act as galactic fountains, with the fraction of galaxies with escaping winds increasing with decreasing potential well depth. We further investigate the physical properties of the outflowing gas finding evidence for enhanced attenuation in the outflow, possibly due to metal-enriched winds, and higher excitation compared to the gas in the galactic disk. Given that the majority of previous studies have focused on more extreme systems with higher SFRs and/or more luminous AGN, our study provides a unique view of the non-gravitational gaseous motions within ‘typical’ galaxies in the low-redshift Universe, where low-luminosity AGN and star formation contribute jointly to the observed outflow phenomenology.

BASS XXXI: Outflow scaling relations in low redshift X-ray AGN host galaxies with MUSE

“…However, this drop is not uniform as the velocity and flux distributions both show clumpy profiles within the outflowing medium. We note that the outflow across the FoV might not be entirely due to the AGN, as the asymmetry in the [O ] line profile could result from residual turbulence from star formation or supernovae driven winds (e.g., Davies et al 2019;Avery et al 2021;Herrera-Camus et al 2021). The electron density map also shows a non-uniform distribution, similar to the ones observed previously in the literature with lower spatial resolution data (e.g., Kakkad et al 2018).…”

Anomaly detection in Hyper Suprime-Cam galaxy images with generative adversarial networks

“…For most of the lines, but particularly H𝛼 and OIIId, there is a large component on the blue side. The strength of this asymmetry is highly unusual, though some asymmetry has been observed in dwarf galaxies with gas outflows or inflows in MaNGA (Wylezalek et al 2020;Avery et al 2021), as well as in some extremely metal-poor dwarf galaxies (EMPGs) in the EMPRESS sample (Kojima et al 2019). This initially suggests that our source is a dwarf galaxy with a gaseous outflow; we investigate this possibility by looking at the components of the flux fit.…”

The SAMI Galaxy Survey: the difference between ionised gas and stellar velocity dispersions

“…Gas outflows powered by AGN may inflate gas velocity dispersions, explaining the correlation between Δ𝜎 and 𝐶 AGN . Avery et al (2021), however, reported that the mass outflow rates depend on the luminosity of AGN and SFR, indicating that both starbursts and AGN are physical drivers of galactic outflows. In this study, we do not find a connection between the current SFR (or SFR normalised by the main sequence, following Avery et al 2021) and Δ𝜎 (see Varidel et al 2020), so there is no direct evidence linking the physical drivers of gas outflows and the impact of outflows on gas kinematics.…”

“…Avery et al (2021), however, reported that the mass outflow rates depend on the luminosity of AGN and SFR, indicating that both starbursts and AGN are physical drivers of galactic outflows. In this study, we do not find a connection between the current SFR (or SFR normalised by the main sequence, following Avery et al 2021) and Δ𝜎 (see Varidel et al 2020), so there is no direct evidence linking the physical drivers of gas outflows and the impact of outflows on gas kinematics. Another possible explanation for enhanced Δ𝜎, especially valid for LINER, is dynamically-warm diffuse ionised gas powered by evolved stars (Belfiore et al 2016;Law et al 2021).…”

“…They are found to be common in galaxies with high SFR (Heckman 2002;Rupke, Veilleux & Sanders 2005a,b;Weiner et al 2009;Steidel et al 2010). Avery et al (2021) also identified evidence of outflows in 322 of 2744 galaxies using MaNGA IFS data, and reported strong correlations between mass outflow rates and both star formation rate and AGN luminosity. In this study, however, we found a negative correlation between Δ𝜎 and SFR (Figure 5), suggesting the current status of star-forming activity may not be as important in boosting 𝜎 gas and determining Δ𝜎.…”