Daftar Isi: The molecular gas and dust content in 'typical' star-forming galaxies at z = 1.46 & 2.23 as revealed by ALMA

Daftar Isi:

We show ALMA observations to 'typical' H-alpha star-forming galaxies at z=1.46 and 2.23 selected from the High-z Emission Line Survey (HiZELS). The galaxies have previously got AO-assisted H-alpha observations with SINFONI at ~0.2" (~1kpc) resolution revealing thick rotating disks presenting massive clumps of star-formation. Using ALMA Band-3 we observe large and massive reservoirs of cold molecular gas with masses which are usually ~2-3 times larger than that seen in stars, more extended, and show smooth radial profiles without significant clumpy structures (as those seen by SINFONI). One galaxy is resolved in CO(2-1) at 0.2" resolution revealing that both phases of the ISM, ionised an molecular, have similar rotation velocity and velocity dispersion at ~100km/s levels. We observe a flat rotation curve up to 2x its half-light radius, so assuming a thick rotating disk we can put constraints on its dynamical mass (~1.5*10^11Mo) and dark-matter fraction (f_DM~0.6). Even though HiZELS galaxies cover a wide parameter space in terms of gas content, their integrated properties still follow the Schmidt-Kennicutt law, similarly to `normal' galaxies seen in the local Universe. Using ALMA Band-7 we derive the H-alpha dust-corrected star-formation rates, finding that these galaxies fall in the so-called `long-lasting mode' of star-formation which could continue up to the present day at that fixed SFR.