Nantais, J.Wilson, GillianMuzzin, AdamOld, Lyndsay JDemarco, R.Cerulo, PierluigiBalogh, MichaelRudnick, GregoryChan, JeffreyCooper, Michael CLidman, Chris2023-03-232023-03-230035-8711http://hdl.handle.net/1885/287309We calculate H α-based star formation rates and determine the star formation rate-stellar mass relation for members of three Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS) clusters at z ∼1.6 and serendipitously identified field galaxies at similar redshifts to the clusters. We find similar star formation rates in cluster and field galaxies throughout our range of stellar masses. The results are comparable to those seen in other clusters at similar redshifts, and consistent with our previous photometric evidence for little quenching activity in clusters. One possible explanation for our results is that galaxies in our z ∼1.6 clusters have been accreted too recently to show signs of environmental quenching. It is also possible that the clusters are not yet dynamically mature enough to produce important environmental quenching effects shown to be important at low redshift, such as ram-pressure stripping or harassment.Our research team recognizes support from the following grants: Universidad Andres Bello internal research project DI-12-19/R (JN), Basal Center for Astrophysics and Associated Technologies (CATA) grant AFB-170002 (RD), and Atacama Large Millimeter Array - Comision Nacional de Investigaci ´ on en Ciencia y Tecnolog ´ ´ıa (ALMA-CONICYT) grant no 31180051 (PC). This work was supported in part by National Science Foundation (NSF) grants AST1517863, AST-1518257, and AST-1815475. Additional support was provided by the National Aeronautics and NASA through grants GO15294 and AR-14289 from the Space Telescope Science Institute (STSCI), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. Support is acknowledged from a European Space Agency (ESA) research fellowship (LJO) and by grant number 80NSSC17K0019 issued through the NASA Astrophysics Data Analysis Program (ADAP).application/pdfen-AU© 2020 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reservedgalaxies: clusters: generalgalaxies: evolution202010.1093/mnras/staa28722022-01-16