DUVET Survey: Mapping Outflows in the Metal-Poor Starburst Mrk 1486

TL;DR

This paper introduces a simple, effective method to characterize star-formation driven outflows in edge-on, metal-poor starburst galaxies using emission line flux distribution, applicable to low-resolution data, demonstrated on Mrk 1486.

Contribution

The paper presents a new technique to identify and measure outflows in galaxies using emission line flux, suitable for low spectral resolution observations, demonstrated on Mrk 1486.

Findings

Outflow asymmetry observed in Mrk 1486.

Estimated outflow opening angle of 17-37 degrees.

Mass outflow rate of approximately 2.5 solar masses per year.

Abstract

We present a method to characterize star-formation driven outflows from edge-on galaxies and apply this method to the metal-poor starburst galaxy, Mrk 1486. Our method uses the distribution of emission line flux (from H$\beta$ and [OIII] 5007) to identify the location of the outflow and measure the extent above the disk, the opening angle, and the transverse kinematics. We show that this simple technique recovers a similar distribution of the outflow without requiring complex modelling of line-splitting or multi-Gaussian components, and is therefore applicable to lower spectral resolution data. In Mrk 1486 we observe an asymmetric outflow in both the location of the peak flux and total flux from each lobe. We estimate an opening angle of $17-37^{\circ}$ depending on the method and assumptions adopted. Within the minor axis outflows, we estimate a total mass outflow rate of $\sim2.5$ M$_{\odot}$ yr$^{-1}$, which corresponds to a mass loading factor of $\eta=0.7$. We observe a non-negligible amount of flux from ionized gas outflowing along the edge of the disk (perpendicular to the biconical components), with a mass outflow rate $\sim0.9$ M$_{\odot}$ yr$^{-1}$. Our results are intended to demonstrate a method that can be applied to high-throughput, low spectral resolution observations, such as narrow band filters or low spectral resolution IFS that may be more able to recover the faint emission from outflows.