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The nuclear starburst within the central $\sim 15^{\prime\prime}$ ($\sim 250$ pc; $1^{\prime\prime} \simeq 17$ pc) of NGC253 has been extensively studied as a prototype for the starburst phase in galactic evolution. Atacama Large Millimeter/submillimeter Array (ALMA) imaging within receiver Bands 6 and 7 have been used to investigate the dense gas structure, kinetic temperature, and heating processes which drive the NGC253 starburst. Twenty-nine transitions from fifteen molecular species/isotopologues have been identified and imaged at $1.^{\prime\prime}5$ to $0.^{\prime\prime}4$ resolution, allowing for the identification of five of the previously-studied giant molecular clouds (GMCs) within the central molecular zone (CMZ) of NGC253. Ten transitions from the formaldehyde (H$_2$CO) molecule have been used to derive the kinetic temperature within the $\sim 0.^{\prime\prime}5$ to $5^{\prime\prime}$ dense-gas structures imaged. On $\sim 5^{\prime\prime}$ scales we measure $T_K \gtrsim 50$ K, while on size scales $\lesssim 1^{\prime\prime}$ we measure $T_K \gtrsim 300$ K. These kinetic temperature measurements further delineate the association between potential sources of dense gas heating. We have investigated potential heating sources by comparing our measurements to models which predict the physical conditions associated with dense molecular clouds that possess a variety of heating mechanisms. This comparison has been supplemented with tracers of recently-formed massive stars (Br$\gamma$) and shocks ([FeII]). Derived molecular column densities point to a radially-decreasing abundance of molecules with sensitivity to cosmic ray and mechanical heating within the NGC253 CMZ. These measurements are consistent with radio spectral index calculations which suggest a higher concentration of cosmic ray producing supernova remnants within the central 10 pc of NGC253., Comment: 60 pages, 25 figures (whew!), Accepted for publication in ApJ, Latest version includes minor corrections following proof submission

We report ALMA observations of CO(3-2) emission in a sample of 7 Seyfert/LINER galaxies at the unprecedented spatial resolution of 0.1'' = 4-9 pc. Our aim is to explore the close environment of AGN, and the dynamical structures leading to its fueling. The selected galaxies host low-luminosity AGN, and have a wide range of activity types, and barred or ringed morphologies. The observed maps reveal the existence of circum-nuclear disk structures, defined by their morphology and decoupled kinematics. We call these structures "molecular tori", even though they appear often as disks, without holes in the center. They have varied orientations, unaligned with their host galaxy. The radius of the tori ranges from 6 to 27 pc, and their mass from 0.7 10$^7$ to 3.9 10$^7$ Msun. At larger scale, the gas is always piled up in a few 100~pc scale resonant rings, that play the role of a reservoir to fuel the nucleus. In some cases, a trailing spiral is observed inside the ring, providing evidence for feeding processes. Most frequently, the torus and the AGN are slightly off-centered, with respect to the bar-resonant ring position, implying that the black hole is wandering by a few 10~pc amplitude around the center of mass of the galaxy. Our spatial resolution allows us to measure gas velocities inside the sphere of influence of the central black holes. By fitting the observations with different simulated cubes, varying the torus inclination and the black hole mass, it is possible to estimate the mass of the central black hole, which is in general difficult for such late-type galaxies, with only a pseudo-bulge., Comment: 20 pages, 21 figures, accepted in Astron. and Astrophys

We present sub-kpc-scale mapping of the 870 $\mu$m ALMA continuum emission in six luminous ($L_{\rm IR}~\sim~5~\times10^{12}$ L$_{\odot}$) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. Our high-fidelity 0.07$''$-resolution imaging ($\sim$500 pc) reveals robust evidence for structures with deconvolved sizes of $\lesssim$0.5-1 kpc embedded within (dominant) exponential dust disks. The large-scale morphologies of the structures within some of the galaxies show clear curvature and/or clump-like structures bracketing elongated nuclear emission, suggestive of bars, star-forming rings, and spiral arms. In this interpretation, the ratio of the `ring' and `bar' radii (1.9$\pm$0.3) agrees with that measured for such features in local galaxies. These potential spiral/ring/bar structures would be consistent with the idea of tidal disturbances, with their detailed properties implying flat inner rotation curves and Toomre-unstable disks (Q<1). The inferred one-dimensional velocity dispersions ($\sigma_{\rm r}\lesssim$ 70-160 km s$^{-1}$) are marginally consistent with the limits implied if the sizes of the largest structures are comparable to the Jeans length. We create maps of the star formation rate density ($\Sigma_{\rm SFR}$) on $\sim$500 pc scales and show that the SMGs are able to sustain a given (galaxy-averaged) $\Sigma_{\rm SFR}$ over much larger physical scales than local (ultra-)luminous infrared galaxies. However, on 500 pc scales, they do not exceed the Eddington limit set by radiation pressure on dust. If confirmed by kinematics, the potential presence of non-axisymmetric structures would provide a means for net angular momentum loss and efficient star formation, helping to explain the very high star formation rates measured in SMGs., Comment: 18 pages, 6 figures, Accepted to ApJ

We present Atacama Large Millimeter/submillimeter Array (ALMA) resolved observations of molecular gas in galaxies up to $z=0.35$ to characterise the role of global galactic dynamics on the global interstellar medium (ISM) properties. These observations consist of a sub-sample of 39 galaxies taken from the Valpara\'iso ALMA Line Emission Survey (VALES). From the CO($J=1-0)$ emission line, we quantify the kinematic parameters by modelling the velocity fields. We find that the IR luminosity increases with the rotational to dispersion velocity ratio ($V_{\rm rot}/\sigma_v$, corrected for inclination). We find a dependence between $V_{\rm rot}/\sigma_v$ and the [CII]/IR ratio, suggesting that the so-called `[CII] deficit' is related to the dynamical state of the galaxies. We find that global pressure support is needed to reconcile the dynamical mass estimates with the stellar masses in our systems with low $V_{\rm rot}/\sigma_v$ values. The star formation rate (SFR) is weakly correlated with the molecular gas fraction ($f_{\rm H_2}$) in our sample, suggesting that the release of gravitational energy from cold gas may not be the main energy source of the turbulent motions seen in the VALES galaxies. By defining a proxy of the `star formation efficiency' parameter as the SFR divided by the CO luminosity (SFE$'\equiv$ SFR/L$'_{\rm CO}$), we find a constant SFE$'$ per crossing time ($t_{\rm cross}$). We suggest that $t_{\rm cross}$ may be the controlling timescale in which the star formation occurs in dusty $z\sim0.03-0.35$ galaxies., Comment: Accepted for publication in MNRAS. 28 pages, 15 figures, 2 Tables

We present high-resolution (0.17\arcsec $\times$ 0.14\arcsec) Atacama Large Millimeter/submillimeter Array (ALMA) observations of the CO\,(6-5) line, and 435\um\ dust continuum emission within a $\sim$9\arcsec $\times$ 9\arcsec\ area centered on the nucleus of the galaxy NGC\,5135. NGC\,5135 is a well-studied luminous infrared galaxy that also harbors a Compton-thick active galactic nucleus (AGN). At the achieved resolution of 48 $\times$ 40\,pc, the CO\,(6-5) and dust emissions are resolved into gas "clumps" along the symmetrical dust lanes associated with the inner stellar bar. The clumps have radii between $\sim$45-180\,pc and CO\,(6-5) line widths of $\sim$60-88\,\kms. The CO\,(6-5) to dust continuum flux ratios vary among the clumps and show an increasing trend with the \FeII/Br-$\gamma$ ratios, which we interpret as evidence for supernova-driven shocked gas providing a significant contribution to the \co65\ emission. The central AGN is undetected in continuum, nor in CO\,(6-5) if its line velocity width is no less than $\sim$\,40\,\kms. We estimate that the AGN contributes at most 1\% of the integrated CO\,(6-5) flux of 512 $\pm$ 24$\,$Jy\kms\ within the ALMA field of view, which in turn accounts for $\sim$32\% of the CO\,(6-5) flux of the whole galaxy., Comment: 21 pages, 12 figures, Accepted for publication in ApJ

The potential similarity of the powering mechanisms of relativistic SNe and GRBs allowed us to make a prediction that relativistic SNe are born in environments similar to those of GRBs, that is, ones which are rich in atomic gas. Here we embark on testing this hypothesis by analysing the properties of the host galaxy NGC 3278 of the relativistic SN 2009bb. This is the first time the atomic gas properties of a relativistic SN host are provided and the first time resolved 21 cm-hydrogen-line (HI) information is provided for a host of an SN of any type in the context of the SN position. We obtained radio observations with ATCA covering the HI line, and optical integral field unit spectroscopy observations with MUSE. The atomic gas distribution of NGC 3278 is not centred on the optical galaxy centre, but instead around a third of atomic gas resides in the region close to the SN position. This galaxy has a few times lower atomic and molecular gas masses than predicted from its SFR. SN 2009bb exploded close to the region with the highest SFR density and the lowest age (~5.5 Myr, corresponding to the initial mass of the progenitor star ~36 Mo). As for GRB hosts, the gas properties of NGC 3278 are consistent with a recent inflow of gas from the intergalactic medium, which explains the concentration of atomic gas close to the SN position and the enhanced SFR. Super-solar metallicity at the position of the SN (unlike for most GRBs) may mean that relativistic explosions signal a recent inflow of gas (and subsequent star formation), and their type (GRBs or SNe) is determined either i) by the metallicity of the inflowing gas, so that metal-poor gas results in a GRB explosion and metal-rich gas results in a relativistic SN explosion without an accompanying GRB, or ii) by the efficiency of gas mixing, or iii) by the type of the galaxy., Comment: Accepted by A&A. 18 pages, 9 figures, 7 tables. The ATCA and VLT/MUSE data will be available through CDS linked in the published version

The most intensively star-forming galaxies are extremely luminous at far-infrared (FIR) wavelengths, highly obscured at optical and ultraviolet wavelengths, and lie at $z\ge 1-3$. We present a programme of ${\it Herschel}$ FIR spectroscopic observations with the SPIRE FTS and photometric observations with PACS, both on board ${\it Herschel}$, towards a sample of 45 gravitationally lensed, dusty starbursts across $z\sim 1-3.6$. In total, we detected 27 individual lines down to 3-$\sigma$, including nine $[\rm C{\small II}]$ 158-$\mu$m lines with confirmed spectroscopic redshifts, five possible $[\rm C{\small II}]$ lines consistent with their far-infrared photometric redshifts, and in some individual sources a few $[\rm O{\small III}]$ 88-$\mu$m, $[\rm O{\small III}]$ 52-$\mu$m, $[\rm O{\small I}]$ 145-$\mu$m, $[\rm O{\small I}]$ 63-$\mu$m, $[\rm N{\small II}]$ 122-$\mu$m, and OH 119-$\mu$m (in absorption) lines. To derive the typical physical properties of the gas in the sample, we stack all spectra weighted by their intrinsic luminosity and by their 500-$\mu$m flux densities, with the spectra scaled to a common redshift. In the stacked spectra, we detect emission lines of $[\rm C{\small II}]$ 158-$\mu$m, $[\rm N{\small II}]$ 122-$\mu$m, $[\rm O{\small III}]$ 88-$\mu$m, $[\rm O{\small III}]$ 52-$\mu$m, $[\rm O{\small I}]$ 63-$\mu$m, and the absorption doublet of OH at 119-$\mu$m, at high fidelity. We find that the average electron densities traced by the $[\rm N{\small II}]$ and $[\rm O{\small III}]$ lines are higher than the average values in local star-forming galaxies and ULIRGs, using the same tracers. From the $[\rm N{\small II}]/[\rm C{\small II}]$ and $[\rm O{\small I}]/[\rm C{\small II}]$ ratios, we find that the $[\rm C{\small II}]$ emission is likely dominated by the photo-dominated regions (PDR), instead of by ionised gas or large-scale shocks., Comment: 39 pages, 19 figures, Accepted for publication in MNRAS. For extra pptx slides prepared for this work, please see http://www.eso.org/~zzhang/download/FTS_SMG_survey_ZhiyuZhang.pdf

We present the results from our Atacama Large Millimeter/submillimeter Array (ALMA) imaging observations of the CO (7-6), [CI] 370 um (hereafter [CI]) and [NII] 205 um (hereafter [NI]I) lines and their underlying continuum emission of BRI 1335-0417, an infrared bright quasar at z = 4.407. At the achieved resolutions of 1.1" to 1.2" (or 7.5 to 8.2 kpc), the continuum at 205 and 372 um (rest-frame), the CO (7-6), and the [CI] emissions are at best barely resolved whereas the [NII] emission is well resolved with an ALMA beam de-convolved major axis of 1.3" (+/- 0.3") or 9 (+/-2) kpc. As a warm dense gas tracer, the CO (7-6) emission shows a more compact spatial distribution and a significantly higher peak velocity dispersion than the other two lines that probe lower density gas, a picture favoring a merger-triggered star formation (SF) scenario over an orderly rotating SF disk. The CO (7-6) data also indicate a possible QSO-driven gas outflow that reaches a maximum line-of-sight velocity of 500 to 600 km/s. The far-infrared (FIR) dust temperature (T_dust) of 41.5 K from a gray-body fit to the continuum agrees well with the average T_dust inferred from various line luminosity ratios. The resulting L_CO(7-6)/L_FIR luminosity ratio is consistent with that of local luminous infrared galaxies powered predominantly by SF. The CO(7-6) luminosity-inferred SF rate is 5.1 (+/-1.5) x 10^3 M_solar/yr . The system has an effective star-forming region of 1.7 (+1.7/-0.8) kpc in diameter and a molecular gas reservoir of ~5 x 10^{11} M_solar., Comment: 14 pages, 7 figures; accepted for publication in the Astrophysical Journal

We describe the application of the supervised machine-learning algorithms to identify the likely multi-wavelength counterparts to submillimeter sources detected in panoramic, single-dish submillimeter surveys. As a training set, we employ a sample of 695 ($S_{\rm 870\mu m}$ >1 mJy) submillimeter galaxies (SMGs) with precise identifications from the ALMA follow-up of the SCUBA-2 Cosmology Legacy Survey's UKIDSS-UDS field (AS2UDS). We show that radio emission, near-/mid-infrared colors, photometric redshift, and absolute $H$-band magnitude are effective predictors that can distinguish SMGs from submillimeter-faint field galaxies. Our combined radio+machine-learning method is able to successfully recover $\sim$85 percent of ALMA-identified SMGs which are detected in at least three bands from the ultraviolet to radio. We confirm the robustness of our method by dividing our training set into independent subsets and using these for training and testing respectively, as well as applying our method to an independent sample of $\sim$100 ALMA-identified SMGs from the ALMA/LABOCA ECDF-South Survey (ALESS). To further test our methodology, we stack the 870$\mu$m ALMA maps at the positions of those $K$-band galaxies that are classified as SMG counterparts by the machine-learning but do not have a $>$4.3$ \sigma$ ALMA detection. The median peak flux density of these galaxies is $S_{\rm 870\mu m}=(0.61\pm0.03)$ mJy, demonstrating that our method can recover faint and/or diffuse SMGs even when they are below the detection threshold of our ALMA observations. In future, we will apply this method to samples drawn from panoramic single-dish submillimeter surveys which currently lack interferometric follow-up observations, to address science questions which can only be tackled with large, statistical samples of SMGs., Comment: 25 pages, 10 figures, three tables, accepted for publication in ApJ

We present ALMA observations of the mid-J 12CO emission from six single-dish selected 870-micron sources in the Extended Chandra Deep Field-South (ECDFS) and UKIDSS Ultra-Deep Survey (UDS) fields. These six single-dish submillimetre sources were selected based on previous ALMA continuum observations, which showed that each comprised a blend of emission from two or more individual submillimetre galaxies (SMGs), separated on 5--10 arcsec scales. The six single-dish submillimetre sources targeted correspond to a total of 14 individual SMGs, of which seven have previously-measured robust optical/near-infrared spectroscopic redshifts, which were used to tune our ALMA observations. We detect CO(3-2) or CO(4-3) at z=2.3--3.7 in seven of the 14 SMGs, and in addition serendipitously detect line emission from three gas-rich companion galaxies, as well as identify four new 3.3-mm selected continuum sources in the six fields. Joint analysis of our CO spectroscopy and existing data suggests that 64 \pm 18% of the SMGs in blended submillimetre sources are unlikely to be physically associated. However, three of the SMG fields (50%) contain new, serendipitously-detected CO-emitting (but submillimetre-faint) sources at similar redshifts to the 870-micron selected SMGs we targeted. These data suggest that the SMGs inhabit overdense regions, but that these are not sufficiently overdense on ~100 kpc scales to influence the source blending given the short lifetimes of SMGs. We find that 21 \pm 12% of SMGs have spatially-distinct and kinematically-close companion galaxies (~8--150 kpc and <~300 km/s), which may have enhanced their star-formation via gravitational interactions., Comment: MNRAS in press

Hyperluminous infrared galaxies (HyLIRGs) provide crucial "long lever arm" constraints on galaxy evolution. H-ATLAS $J084933.4+021443$, a $z=2.41$ binary HyLIRG with at least two additional luminous companion galaxies, is thus an optimal test-ground for studies of star formation and galaxy evolution during "cosmic noon". We have used ALMA to obtain resolved imaging and kinematics of atomic and molecular emission lines, and rest-frame $340$ to $1160$GHz continuum emission, for the known luminous component galaxies in H-ATLAS $J084933.4+021443$: W, T, M, C. All four component galaxies are spatially ($\sim 0 .\!\!^{''} 3$ or $2.5$kpc) resolved in CO J:7-6, [C$_\mathrm{I}$] 2-1, H$_2$O and the millimetre (mm) to sub-mm continuum. Rotation-dominated gas kinematics is confirmed in W and T. The significant extension to component T, in gas and continuum, along its kinematic minor axis, is attributable to its lensing magnification. Spatially resolved sub-mm spectral energy distributions reveal that component W is well fit with greybody emission from dust at a single temperature over the full extent of the galaxy, despite it containing a powerful AGN, while component T requires an additional component of hotter nuclear dust and additional sources of emission in the mm. We confirm that [C$_\mathrm{I}$] 2-1 can be used as a rough tracer of warm/dense molecular gas in extreme systems, though the [C$_\mathrm{I}$] 2-1/CO luminosity ratio increases sub-linearly. We obtain an exquisite and unprecedented resolved ($2.5$-kpc-scale) "warm/dense molecular gas" Schmidt-Kennicutt (SK) relationship for components W and T. Gas exhaustion times for all apertures in W (T) are $1-4$Gyr ($0.5-2$Gyr). Both W and T follow a resolved "warm/dense gas" SK relationship with power law $n\sim1.7$, significantly steeper than the $n\sim1$ found previously via "cold" molecular gas in nearby "normal" star-forming galaxies.

Aiming to characterise the properties of the molecular gas in the ultraluminous infrared galaxy Mrk273 and its outflow, we used the NOEMA interferometer to image the dense gas molecular tracers HCN, HCO+, HNC, HOC+ and HC3N at 86GHz and 256GHz with angular resolutions of 4.9x4.5 arcsec (3.7x3.4 kpc) and 0.61x0.55 arcsec (460x420 pc). We also modelled the flux of several H2O lines observed with Herschel using a radiative transfer code that includes excitation by collisions as well as by far-infrared photons. The disk of the Mrk273 north nucleus has two components with decoupled kinematics. The gas in the outer parts (1.5 kpc) rotates with a south-east to north-west direction, while in the inner disk (300 pc) follows a north-east to south-west rotation. The central 300 pc, which hosts a compact starburst region, is filled with dense and warm gas, contains a dynamical mass of (4-5)x10^9M_sun, a luminosity of L'_HCN=(3-4)x10^8 K km/s pc^2, and a dust temperature of 55 K. At the very centre, a compact core with R~50 pc has a luminosity of L_IR=4x10^11L_sun (30% of the total infrared luminosity), and a dust temperature of 95 K. The core is expanding at low velocities ~50-100 km/s, probably affected by the outflowing gas. We detect the blue-shifted component of the outflow, while the red-shifted counterpart remains undetected in our data. Its cold and dense phase reaches fast velocities up to ~1000 km/s, while the warm outflowing gas has more moderate maximum velocities of ~600 km/s. The outflow is detected as far as 460 pc from the centre in the northern direction, and has a mass of dense gas <8x10^8M_sun. The difference between the position angles of the inner disk (~70 degree) and the outflow (~10 degree) indicates that the outflow is likely powered by the AGN, and not by the starburst. Regarding the chemistry, we measure an extremely low HCO+/HOC+ ratio of 10+-5 in the inner disk of Mrk273., Comment: Accepted for publication in A&A. 21 pages, 17 figures, 7 tables, and a lot of interesting text

We report the first results of AS2UDS: an 870 $\mu$m continuum survey with the Atacama Large Millimeter/Submillimeter Array (ALMA) of a total area of $\sim$ 50 arcmin$^2$ comprising a complete sample of 716 submillimeter sources drawn from the SCUBA-2 Cosmology Legacy Survey (S2CLS) map of the UKIDSS/UDS field. The S2CLS parent sample covers a 0.96 degree$^2$ field at $\sigma_{850}=0.90\pm0.05$ mJy beam$^{-1}$. Our deep, high-resolution ALMA observations with $\sigma_{\rm 870}\sim$ 0.25 mJy and a 0.15"--0.30" FWHM synthesized beam, provide precise locations for 695 submillimetre galaxies (SMGs) responsible for the submillimeter emission corresponding to 606 sources in the low resolution, single-dish map. We measure the number counts of SMGs brighter than $S_{\rm 870}\geq$ 4 mJy, free from the effects of blending and show that the normalisation of the counts falls by 28 $\pm$ 2% in comparison to the SCUBA-2 parent sample, but that the shape remains unchanged. We determine that 44$^{+16}_{-14}$% of the brighter single-dish sources with $S_{850}\geq$ 9 mJy consist of a blend of two or more ALMA-detectable SMGs brighter than $S_{870}\sim$ 1 mJy (corresponding to a galaxy with a total-infrared luminosity of $L_{IR}\geq$ 10$^{12}$ L$_\odot$), in comparison to 28 $\pm$ 2% for the single-dish sources at $S_{\rm 850}\geq$ 5 mJy. Using the 46 single-dish submillimeter sources that contain two or more ALMA-detected SMGs with photometric redshifts, we show that there is a significant statistical excess of pairs of SMGs with similar redshifts ($<$1% probability of occurring by chance), suggesting that at least 30% of these blends arise from physically associated pairs of SMGs., Comment: 11 pages, 4 figures, fixed typo (sorry Rob)

We report the results of a search for serendipitous [CII] 157.74$\mu$m emitters at $z\sim4.4$-$4.7$ using the Atacama Large Millimeter/submillimeter Array (ALMA). The search exploits the AS2UDS continuum survey, which covers ~50 arcmin$^2$ of the sky towards 695 luminous ($S_{870}\gtrsim1$mJy) submillimeter galaxies (SMGs), selected from the SCUBA-2 Cosmology Legacy Survey (S2CLS) 0.96deg$^2$ Ultra Deep Survey (UDS) field. We detect ten candidate line emitters, with an expected false detection rate of ten percent. All of these line emitters correspond to 870$\mu$m continuum-detected sources in AS2UDS. The emission lines in two emitters appear to be high-J CO, but the remainder have multi-wavelength properties consistent with [CII] from $z\simeq4.5$ galaxies. Using our sample, we place a lower limit of $>5\times10^{-6}$Mpc$^{-3}$ on the space density of luminous ($L_{\rm IR} \simeq 10^{13}$Lsun) SMGs at $z=4.40$-$4.66$, suggesting $\ge7$percent of SMGs with $S_{870\mu{\rm m}}\gtrsim1$mJy lie at $4

We present new CO(2-1) observations of 3 low-z (~350 Mpc) ULIRG systems (6 nuclei) observed with ALMA at high-spatial resolution (~500 pc). We detect massive cold molecular gas outflows in 5 out of 6 nuclei (0.3-5)x10^8 Msun. These outflows are spatially resolved with deprojected radii of 0.25-1 kpc although high-velocity molecular gas is detected up to ~0.5-1.8 kpc (1-6 kpc deprojected). The mass outflow rates are 12-400 Msun/yr and the inclination corrected average velocity of the outflowing gas 350-550 km/s (v_max = 500-900 km/s). The origin of these outflows can be explained by the nuclear starbursts although the contribution of an obscured AGN can not be completely ruled out. The position angle (PA) of the outflowing gas along the kinematic minor axis of the nuclear molecular disk suggests that the outflow axis is perpendicular to the disk for three of these outflows. Only in one case, the outflow PA is clearly not along the kinematic minor axis. The outflow depletion times are 15-80 Myr which are slightly shorter than the star-formation (SF) depletion times (30-80 Myr). However, we estimate that only 15-30% of the outflowing gas will escape the gravitational potential of the nucleus. The majority of the outflowing gas will return to the disk after 5-10 Myr and become available to form new stars. Therefore, these outflows will not likely quench the nuclear starbursts. These outflows would be consistent with being driven by radiation pressure (momentum-driven) only if the coupling between radiation and dust increases with increasing SF rates. This can be achieved if the dust optical depth is higher in objects with higher SF. The relatively small sizes (<1 kpc) and dynamical times (<3 Myr) of the cold molecular outflows suggests that molecular gas cannot survive longer in the outflow environment or that it cannot form efficiently beyond these distances or times. (Abridged), Comment: Accepted for publication in A&A; 20 pages, 18 figures

We use ALMA observations of four sub-millimetre galaxies (SMGs) at $z\sim2-3$ to investigate the spatially resolved properties of the inter-stellar medium (ISM) at scales of 1--5 kpc (0.1--0.6$''$). The velocity fields of our sources, traced by the $^{12}$CO($J$=3-2) emission, are consistent with disk rotation to first order, implying average dynamical masses of $\sim$3$\times10^{11}$M$_{\odot}$ within two half-light radii. Through a Bayesian approach we investigate the uncertainties inherent to dynamically constraining total gas masses. We explore the covariance between the stellar mass-to-light ratio and CO-to-H$_{2}$ conversion factor, $\alpha_{\rm CO}$, finding values of $\alpha_{\rm CO}=1.1^{+0.8}_{-0.7}$ for dark matter fractions of 15 \%. We show that the resolved spatial distribution of the gas and dust continuum can be uncorrelated to the stellar emission, challenging energy balance assumptions in global SED fitting. Through a stacking analysis of the resolved radial profiles of the CO(3-2), stellar and dust continuum emission in SMG samples, we find that the cool molecular gas emission in these sources (radii $\sim$5--14 kpc) is clearly more extended than the rest-frame $\sim$250 $\mu$m dust continuum by a factor $>2$. We propose that assuming a constant dust-to-gas ratio, this apparent difference in sizes can be explained by temperature and optical-depth gradients alone. Our results suggest that caution must be exercised when extrapolating morphological properties of dust continuum observations to conclusions about the molecular gas phase of the ISM., Comment: Submitted to ApJ, 16 pages, 6 figures

Improvements in both theory and frequency metrology of few-electron systems such as hydrogen and helium have enabled increasingly sensitive tests of quantum electrodynamics (QED), as well as ever more accurate determinations of fundamental constants and the size of the nucleus. At the same time advances in cooling and trapping of neutral atoms have revolutionized the development of increasingly accurate atomic clocks. Here, we combine these fields to reach the highest precision on an optical tranistion in the helium atom to date by employing a Bose-Einstein condensate confined in a magic wavelength optical dipole trap. The measured transition accurately connects the ortho- and parastates of helium and constitutes a stringent test of QED theory. In addition we test polarizability calculations and ultracold scattering properties of the helium atom. Finally, our measurement probes the size of the nucleus at a level exceeding the projected accuracy of muonic helium measurements currently being performed in the context of the proton radius puzzle.

We obtained CO(2-1) observations of seven GRB hosts with the APEX and IRAM 30m telescopes. We analysed these data together with all other hosts with previous CO observations. We obtained detections for 3 GRB hosts (980425, 080207, and 111005A) and upper limits for the remaining 4 (031203, 060505, 060814, and 100316D). In our entire sample of 12 CO-observed GRB hosts, 3 are clearly deficient in molecular gas, even taking into account their metallicity (980425, 060814, and 080517). Four others are close to the best-fit line for other star-forming galaxies on the SFR-MH2 plot (051022, 060505, 080207, and 100316D). One host is clearly molecule rich (111005A). Finally, the data for 4 GRB hosts are not deep enough to judge whether they are molecule deficient (000418, 030329, 031203, and 090423). The median value of the molecular gas depletion time, MH2/SFR, of GRB hosts is ~0.3 dex below that of other star-forming galaxies, but this result has low statistical significance. A Kolmogorov-Smirnov test performed on MH2/SFR shows an only ~2sigma difference between GRB hosts and other galaxies. This difference can partly be explained by metallicity effects, since the significance decreases to ~1sigma for MH2/SFR versus~metallicity. We found that any molecular gas deficiency of GRB hosts has low statistical significance and that it can be attributed to their lower metallicities; and thus the sample of GRB hosts has molecular properties that are consistent with those of other galaxies, and they can be treated as representative star-forming galaxies. Given the concentration of atomic gas recently found close to GRB and supernova sites, indicating recent gas inflow, our results about the weak molecular deficiency imply that such an inflow does not enhance the SFRs significantly, or that atomic gas converts efficiently into the molecular phase, which fuels star formation., Comment: Published in A&A. 12 pages, 5 figures, 4 tables

We present deep high resolution (0.03", 200pc) ALMA Band 7 observations covering the dust continuum and [CII] $\lambda157.7\mu$m emission in four $z\sim4.4-4.8$ sub-millimeter galaxies (SMGs) selected from the ALESS and AS2UDS surveys. The data show that the rest-frame 160$\mu$m (observed 345 GHz) dust emission is consistent with smooth morphologies on kpc scales for three of the sources. One source, UDS47.0, displays apparent substructure but this is also consistent with a smooth morphology, as indicated by simulations showing that smooth exponential disks can appear clumpy when observed at high angular resolution (0.03") and depth of these observations ($\sigma_{345\text{GHz}} \sim27-47\mu$Jy beam$^{-1}$). The four SMGs are bright [CII] emitters, and we extract [CII] spectra from the high resolution data, and recover $\sim20-100$% of the [CII] flux and $\sim40-80$% of the dust continuum emission, compared to the previous lower resolution observations. When tapered to 0.2" resolution our maps recover $\sim80-100$% of the continuum emission, indicating that $\sim60$% of the emission is resolved out on $\sim200$pc scales. We find that the [CII] emission in high-redshift galaxies is more spatially extended than the rest-frame 160$\mu$m dust continuum by a factor of $1.6\pm0.4$. By considering the $L_{\text{[CII]}}$/$L_{\text{FIR}}$ ratio as a function of the star-formation rate surface density ($\Sigma_{\text{SFR}}$) we revisit the [CII] deficit, and suggest that the decline in the $L_{\text{[CII]}}$/$L_{\text{FIR}}$ ratio as a function of $\Sigma_{\text{SFR}}$ is consistent with local processes. We also explore the physical drivers that may be responsible for these trends and can give rise to the properties found in the densest regions of SMGs., Comment: 15 pages, 6 figures, 4 tables, accepted for publication in ApJ