JCMT Observing: An efficient survey of obscured star formation in the high redshift (4 < z < 7) Universe

Lead Research Organisation: University of Sussex
Department Name: Sch of Mathematical & Physical Sciences


Dr. Jillian Scudder will be travelling to the JCMT telescope on Mauna Kea in order to serve as an observer for that telescope for five days.


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Duivenvoorden S (2018) Red, redder, reddest: SCUBA-2 imaging of colour-selected Herschel sources in Monthly Notices of the Royal Astronomical Society

Description High-redshift, luminous, dusty star-forming galaxies (DSFGs) constrain the extremity of galaxy formation theories. The most extreme are discovered through follow-up on candidates in large area surveys. Here, we present extensive 850 µm SCUBA-2 follow-up observations of 188 red DSFG candidates from the Herschel Multitiered Extragalactic Survey (HerMES) Large Mode Survey, covering 274 deg2. We detected 87 per cent with a signal-to-noise ratio >3 at 850 µm. We introduce a new method for incorporating the confusion noise in our spectral energy distribution fitting by sampling correlated flux density fluctuations from a confusion limited map. The new 850 µm data provide a better constraint on the photometric redshifts of the candidates, with photometric redshift errors decreasing from sz/(1 + z) ˜ 0.21 to 0.15. Comparison spectroscopic redshifts also found little bias (<(z - zspec)/(1 + zspec)> = 0.08). The mean photometric redshift is found to be 3.6 with a dispersion of 0.4 and we identify 21 DSFGs with a high probability of lying at z > 4. After simulating our selection effects we find number counts are consistent with phenomenological galaxy evolution models. There is a statistically significant excess of WISE-1 and SDSS sources near our red galaxies, giving a strong indication that lensing may explain some of the apparently extreme objects. Nevertheless, our sample includes examples of galaxies with the highest star formation rates in the Universe (»103 M? yr-1).
Exploitation Route In academic research
Sectors Education