Résumé / Abstract Journal-club_Galaxies

Séminaire/Seminar Galaxies

«  z-GAL - A NOEMA Redshift Survey of Bright Herschel Galaxies »

Pierre Cox
On behalf of the z-GAL Team - Institut d'Astrophysique de Paris (Paris, France)

The Herschel surveys have enabled the detection of numerous dusty luminous sub-millimetre galaxies (SMGs) in the early universe. Follow-up observations of these sources are essential to determine their nature and the physical properties of their interstellar medium; reliable redshift measurements are therefore crucial to explore the molecular and atomic gas of these objects.

We will here present the results of a Large Program, z-GAL, using NOEMA, aimed at a comprehensive 3 and 2-mm spectroscopic redshift survey of a large (137 sources) sample of the brightest (S500 µm>80 mJy) SMGs selected from the Herschel H-ATLAS, HerMES and HerS surveys. Reliable redshifts were derived for all sources but two, based on the detection of at least two emission lines, making it the largest sample of high-z galaxies with unambiguous redshifts to date. The spectroscopic redshifts are in the range 0.8 < z < 6.5 with a median of z=2.56, centred on the peak epoch of galaxy evolution.

We will describe the main results of the z-GAL survey, highlighting the physical properties of the SMGs derived from the molecular and atomic emission lines and the underlying dust continuum, and comment on the nature of the sources, that include lenses and hyper-luminous galaxies, as well as binary and triple systems. Complementary data, including HST and Keck data, will also be presented. Comparisons with other spectroscopic surveys of high-z galaxies will be shown and future prospects, including follow-up observations based on these redshifts measurements, outlined.
jeudi 28 septembre 2023 - 11:00
Salle du Conseil
Institut d'Astrophysique de Paris
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