We report Atacama Large Millimetre/submillimeter Array (ALMA) Cycle-5 follow-up observations of two candidate [CII] emitters at z ~ 6 in the ALMA deep field in SSA22 (ADF22). The candidates were detected blindly in a Cycle-2 ALMA survey covering ~ 5 square arcmins, with a single tuning, along with two CO lines associated with galaxies at lower redshifts. Various tests suggested at least one of the two > 6-sigma [CII] candidates should be robust (Hayatsu et al. 2017). Nevertheless, our new, deeper observations recover neither candidate, demonstrating a higher contamination rate than expected. The cause of the spurious detections is under investigation but at present it remains unclarified.
@article{arxiv.1907.05742,
title = {ADF22: Blind detections of [CII] line emitters shown to be spurious},
author = {Natsuki H. Hayatsu and Rob J. Ivison and Paola Andreani and Hideki Umehata and Yuichi Matsuda and Naoki Yoshida and Kotaro Kohno and Bunyo Hatsukade and Akio K. Inoue and Yoichi Tamura and Tutomu T. Takeuchi and Seiji Fujimoto and Minju M. Lee and Tohru Nagao and Yiping Ao},
journal= {arXiv preprint arXiv:1907.05742},
year = {2019}
}
Comments
Submitted to AAS research note. One figure, three pages. Comments, suggestions, questions are welcome. The details will be discussed in Hayatsu et al. in prep