Shivaei, IReddy, Naveen A.Rieke, George H.Shapley, Alice E.Kriek, MariskaBattisti, AndrewMobasher, BahramSanders, RyanFetherolf, TaraAzadi, MojeganCoil, Alison L2022-07-272022-07-271538-4357http://hdl.handle.net/1885/269978We derive a UV-optical stellar dust attenuation curve of galaxies at z = 1.4-2.6 as a function of gas-phase metallicity. We use a sample of 218 star-forming galaxies, excluding those with very young or heavily obscured star formation, from the MOSFIRE Deep Evolution Field survey with Hα, Hβ, and [N ii]λ 6585 spectroscopic measurements. We constrain the shape of the attenuation curve by comparing the average flux densities of galaxies sorted into bins of dust obscuration using Balmer decrements, i.e., Hα-to-Hβ luminosities. The average attenuation curve for the high-metallicity sample ($12+\mathrm{log}({\rm{O}}/{\rm{H}})\gt 8.5$, corresponding to ${M}_{* }\gtrsim {10}^{10.4}$ ${M}_{\odot }$) has a shallow slope, identical to that of the Calzetti local starburst curve, and a significant UV 2175 - extinction bump that is ~0.5x the strength of the Milky Way bump. On the other hand, the average attenuation curve of the low-metallicity sample ($12+\mathrm{log}({\rm{O}}/{\rm{H}})\sim 8.2-8.5$) has a steeper slope similar to that of the SMC curve, only consistent with the Calzetti slope at the 3σ level. The UV bump is not detected in the low-metallicity curve, indicating the relative lack of the small dust grains causing the bump at low metallicities. Furthermore, we find that on average the nebular reddening (E(B − V)) is a factor of 2 times larger than that of the stellar continuum for galaxies with low metallicities, while the nebular and stellar reddening are similar for galaxies with higher metallicities. The latter is likely due to a high surface density of dusty clouds embedding the star-forming regions but also reddening the continuum in the high-metallicity galaxies.Support for this work was provided by NASA through the NASA Hubble Fellowship grant # HST-HF2-51420, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. Funding for the MOSDEF survey was provided by NSF AAG grants AST1312780, 1312547, 1312764, and 1313171 and archival grant AR-13907, provided by NASA through a grant from the Space Telescope Science Institute. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. We are grateful to the MOSFIRE instrument team for building this powerful instrument, and to Marc Kassis at the Keck Observatory for his many valuable contributions to the execution of the MOSDEF surveyapplication/pdfen-AU© 2020. The American Astronomical SocietyGalaxy evolutionInterstellar dust extinctionHigh-redshift galaxiesGalaxy abundancesChemical abundancesGalaxy propertiesGalaxiesInterstellar dustInterstellar abundances202010.3847/1538-4357/aba35e2021-08-01