DISK DISPERSAL AT LOW METALLICITY
Metallicity sets important disks properties and thus it can impact disk dispersal timescale. For instance, dust opacity declines at low metallicity, resulting in a more efficient penetration of energetic photons in disks [Gorti & Hollenbach 2009]. This can increases the effectiveness of magnetic instabilities, which are important for accretion [Hartmann 2009] and magnetically-driven winds [Suzuki+2010]. As a consequence of this, disks dispersal may occur faster in low-metallicity environments [e.g. Ercolano+2009].
Observational studies provide contradictory results: Studies of the stellar population of a few low-metallicity star forming regions in the Outer Galaxy found very low disk fractions compared with regions with a metallicity closer to Solar values [e.g., Yasui+2016a,b]. On the other hands, studies of actively accreting Young Stellar Objects in the Magellanic Clouds found more intense and long-lived accretion rates compared with disk in the Milky Way [e.g., de Marchi+2017].
 
Left panel: Mass accretion rates of stars with disks in Solar metallicity regions (black) and in the low metallicity region around SN1987A in the Large Magellanic Cloud [de Marchi et al. 2010].
Right panel: Disk fraction as a function of clusters age. The black dots are values of clusters with Solar metallicity, red dots with low metallicity in the Outer Galaxy [Yasui et al. 2010].
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