Star Formation at 4 < z < 6 from the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH)

August 2014 • 2014ApJ...791L..25S

Authors • Steinhardt, Charles L. • Speagle, Josh S. • Capak, Peter • Silverman, John D. • Carollo, Marcella • Dunlop, James • Hashimoto, Yasuhiro • Hsieh, Bau-Ching • Ilbert, Olivier • Le Fevre, Olivier • Le Floc'h, Emeric • Lee, Nicholas • Lin, Lihwai • Lin, Yen-Ting • Masters, Dan • McCracken, Henry J. • Nagao, Tohru • Petric, Andreea • Salvato, Mara • Sanders, Dave • Scoville, Nick • Sheth, Kartik • Strauss, Michael A. • Taniguchi, Yoshiaki

Abstract • Using the first 50% of data collected for the Spitzer Large Area Survey with Hyper-Suprime-Cam observations on the 1.8 deg² Cosmological Evolution Survey we estimate the masses and star formation rates of 3398 M _* > 10¹⁰ M _⊙ star-forming galaxies at 4 < z < 6 with a substantial population up to M _* >~ 10^11.5 M _⊙. We find that the strong correlation between stellar mass and star formation rate seen at lower redshift (the "main sequence" of star-forming galaxies) extends to z ~ 6. The observed relation and scatter is consistent with a continued increase in star formation rate at fixed mass in line with extrapolations from lower-redshift observations. It is difficult to explain this continued correlation, especially for the most massive systems, unless the most massive galaxies are forming stars near their Eddington-limited rate from their first collapse. Furthermore, we find no evidence for moderate quenching at higher masses, indicating quenching either has not occurred prior to z ~ 6 or else occurs rapidly, so that few galaxies are visible in transition between star-forming and quenched.

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IPAC Authors
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Elise Furlan

Associate Scientist

Daniel Masters

Assistant Scientist