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We present new Atacama Large Millimeter/Submillimeter Array (ALMA) observations of the [CII] 158 $\mu$m transition and the dust continuum in HZ4, a typical star-forming galaxy when the Universe was only $\sim1$ Gyr old ($z\approx5.5$). Our high $\approx0.3$'' spatial resolution allow us to study the relationships between [CII] line emission, star formation rate (SFR), and far-infrared (FIR) emission on spatial scales of $\sim2$ kpc. In the central $\sim$4 kpc of HZ4, the [CII]/FIR ratio is $\sim3\times10^{-3}$ on global scales as well as on spatially-resolved scales of $\sim$2 kpc, comparable to the ratio observed in local moderate starburst galaxies such as M82 or M83. For the first time in an individual normal galaxy at this redshift, we find evidence for outflowing gas from the central star-forming region in the direction of the minor-axis of the galaxy. The projected velocity of the outflow is $\sim400$ km s$^{-1}$, and the neutral gas mass outflow rate is $\sim3-6$ times higher than the SFR in the central region. Finally, we detect a diffuse component of [CII] emission, or "[CII]-halo", that extends beyond the star-forming disk and has a size of $\sim12$ kpc in diameter. Most likely the outflow, which has a velocity approximately half the escape velocity of the system, is in part responsible for fueling the [CII] extended emission. Together with the kinematic analysis of HZ4 (presented in a forthcoming paper), the analysis supports that HZ4 is a typical star-forming disk at $z\sim5$ with interstellar medium (ISM) conditions similar to present-day galaxies forming stars at a similar level, driving a galactic outflow that may already play a role in its evolution., Comment: Accepted for publication in Astronomy & Astrophysics. 13 pages, 11 figures

We present half-light sizes measured from H$��$ emission tracing star-formation in 281 star-forming galaxies from the KMOS3D survey at 0.7 < z < 2.7. Sizes are derived by fitting 2D exponential disk models, with bootstrap errors averaging 20%. H$��$ sizes are a median (mean) of 1.19 (1.26) times larger than those of the stellar continuum, which due to radial dust gradients places an upper limit on the growth in stellar size via star formation, with just 43% intrinsic scatter. At fixed continuum size the H$��$ size shows no residual trend with stellar mass, star formation rate, redshift or morphology. The only significant residual trend is with the excess obscuration of H$��$ by dust, at fixed continuum obscuration. The scatter in continuum size at fixed stellar mass is likely driven by the scatter in halo spin parameters. The stability of the ratio of H$��$ size to continuum size demonstrates a high degree of stability in halo spin and in the transfer of angular momentum to the disk over a wide range of physical conditions and cosmic time. This may require local regulation by feedback processes. The implication of our results, as we demonstrate using a toy model, is that our upper limit on star-formation driven growth is sufficient only to evolve star-forming galaxies approximately along the observed size-mass relation, consistent with the size growth of galaxies at constant cumulative co-moving number density. To explain the observed evolution of the size-mass relation of star-forming disk galaxies other processes, such as the preferential quenching of compact galaxies or galaxy mergers, may be required., 29 pages, 18 figures, accepted for publication in ApJ. Table C1 will be available in machine readable format with the final published version of the paper

In this work we analyze the physical properties of a sample of 56 spectroscopically selected star-forming (SF) Ly$��$ emitting galaxies at 2.0$\lesssim$z$\lesssim$3.5 using both a spectral energy distribution (SED) fitting procedure from rest-frame UV to mid-IR and direct 160$��$m observations taken with the Photodetector Array Camera & Spectrometer (PACS) instrument onboard \emph{Herschel Space Observatory}. We define LAEs as those Ly$��$ emitting galaxies whose rest-frame Ly$��$ equivalent widths (Ly$��$ EW$_{rest-frame}$) are above 20��, the typical threshold in narrow-band searches. Ly$��$ emitting galaxies with Ly$��$ EW$_{rest-frame}$ are called non-LAEs. As a result of an individual SED fitting for each object, we find that the studied sample of LAEs contains galaxies with ages mostly below 100Myr and a wide variety of dust attenuations, SFRs, and stellar masses. The heterogeneity in the physical properties is also seen in the morphology, ranging from bulge-like galaxies to highly clumpy systems. In this way, we find that LAEs at 2.0$\lesssim$z$\lesssim$3.5 are very diverse, and do not have a bimodal nature, as suggested in previous works. Furthermore, the main difference between LAEs and non-LAEs is their dust attenuation, because LAEs are not as dusty as non-LAEs. On the FIR side, four galaxies of the sample (two LAEs and two non-LAEs) have PACS-FIR counterparts. Their total IR luminosity place all of them in the ULIRG regime and are all dusty objects, with A$_{1200}$$\gtrsim$4mag. This is an indication from direct FIR measurements that dust and Ly$��$ emission are not mutually exclusive. This population of red and dusty LAEs is not seen at z$\sim$0.3, suggesting an evolution with redshift of the IR nature of galaxies selected via their Ly$��$ emission., Accepted for publication in A&A

One remaining open question regarding the physical properties of Ly$��$ emitters (LAEs) is their dust content and its evolution with redshift. The variety of results is large and with those reported by now is difficult to establish clear relations between dust, other fundamental parameters of galaxies (star-formation rate, metallicity or age) and redshift. In this Letter, we report \emph{Herschel} PACS-100$��$m, PACS-160$��$m and \emph{Spitzer} MIPS-24$��$m detections of a sample of spectroscopically GALEX-selected LAEs at z$\sim$0.3 and $\sim$1.0. Five out of ten and one out of two LAEs are detected in, at least, one PACS band at z$\sim$0.3 and $\sim$1.0, respectively. These measurements have a great importance given that they allow us to quantify, for the first time, the dust content of LAEs from direct FIR observations. MIPS-24$��$m detections allow us to determine IR properties of the PACS-undetected LAEs. We obtain that mid-IR/FIR detected star-forming (SF) LAEs at z$\sim$0.3 have dust content within 0.75$\lesssim$ $A_{1200��}$ $\lesssim$2.0, with a median value of A$_{1200\textrm��}$$\sim$1.1. This range broadens out to 0.75$\lesssim$ $A_{1200��}$ $\lesssim$2.5 when considering those LAEs at z$\sim$1.0. Only one SF LAE is undetected both in MIPS-24$��$m and PACS, with $A_{1200��}$ $\lesssim$0.75. These results seem to be larger than those reported for high-redshift LAEs and, therefore, although an evolutionary trend is not clearly seen, it could point out that low-redshift LAEs are dustier than high-redshift ones. However, the diverse methods used could introduce a systematic offset in the results., Accepted for publication in ApJL