TY - JOUR
T1 - PHIBSS
T2 - Searching for Molecular Gas Outflows in Star-forming Galaxies at z = 0.5-2.6
AU - Barfety, Capucine
AU - Jolly, Jean Baptiste
AU - Förster Schreiber, Natascha M.
AU - Tacconi, Linda J.
AU - Genzel, Reinhard
AU - Tozzi, Giulia
AU - Burkert, Andreas
AU - Chen, Jianhang
AU - Combes, Françoise
AU - Davies, Ric
AU - Eisenhauer, Frank
AU - Salcedo, Juan M.Espejo
AU - Herrera-Camus, Rodrigo
AU - Lee, Lilian L.
AU - Lee, Minju M.
AU - Liu, Daizhong
AU - Lutz, Dieter
AU - Naab, Thorsten
AU - Neri, Roberto
AU - Shachar, Amit Nestor
AU - Pastras, Stavros
AU - Pulsoni, Claudia
AU - Price, Sedona H.
AU - Renzini, Alvio
AU - Schuster, Karl
AU - Shimizu, Taro T.
AU - Sternberg, Amiel
AU - Sturm, Eckhard
AU - Übler, Hannah
AU - Wuyts, Stijn
N1 - Publisher Copyright:
© 2025. The Author(s). Published by the American Astronomical Society.
PY - 2025
Y1 - 2025
N2 - We present an analysis of millimeter CO observations to search for and quantify signatures of molecular gas outflows. We exploit the large sample of 0.5 < z < 2.6 galaxies observed as part of the PHIBSS1/2 surveys with the IRAM Plateau de Bure interferometer, focusing on the 154 typical massive star-forming galaxies with CO detections (mainly CO(3–2), but including also CO(2–1) and CO(6–5)) at signal-to-noise ratio (SNR) > 1.5 and available properties (stellar mass, star formation rate or SFR, size) from ancillary data. None of the individual spectra exhibit a compelling signature of CO outflow emission, even at high SNR > 7. To search for fainter outflow signatures, we carry out an analysis of stacked spectra, including the full sample, as well as subsets, split in terms of stellar mass, redshift, inclination, offset in SFR from the main sequence, and active galactic nuclei activity. None of the physically motivated subsamples shows any outflow signature. We report a tentative detection in a subset statistically designed to maximize outflow signatures. We derive upper limits on molecular gas outflow rate and mass loading factors η based on our results and find η ≤ 2.2–35.4, depending on the subsample. Much deeper CO data and observations of alternative tracers are needed to decisively constrain the importance of the cold molecular gas component of outflows relative to other gas phases.
AB - We present an analysis of millimeter CO observations to search for and quantify signatures of molecular gas outflows. We exploit the large sample of 0.5 < z < 2.6 galaxies observed as part of the PHIBSS1/2 surveys with the IRAM Plateau de Bure interferometer, focusing on the 154 typical massive star-forming galaxies with CO detections (mainly CO(3–2), but including also CO(2–1) and CO(6–5)) at signal-to-noise ratio (SNR) > 1.5 and available properties (stellar mass, star formation rate or SFR, size) from ancillary data. None of the individual spectra exhibit a compelling signature of CO outflow emission, even at high SNR > 7. To search for fainter outflow signatures, we carry out an analysis of stacked spectra, including the full sample, as well as subsets, split in terms of stellar mass, redshift, inclination, offset in SFR from the main sequence, and active galactic nuclei activity. None of the physically motivated subsamples shows any outflow signature. We report a tentative detection in a subset statistically designed to maximize outflow signatures. We derive upper limits on molecular gas outflow rate and mass loading factors η based on our results and find η ≤ 2.2–35.4, depending on the subsample. Much deeper CO data and observations of alternative tracers are needed to decisively constrain the importance of the cold molecular gas component of outflows relative to other gas phases.
U2 - 10.3847/1538-4357/addc6f
DO - 10.3847/1538-4357/addc6f
M3 - Journal article
AN - SCOPUS:105010587267
SN - 0004-637X
VL - 988
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 55
ER -