MAHALO-Subaru (MApping HAlpha and Lines of Oxygen with Subaru) project aims to investigate how the star forming activities in galaxies are propagated as a function of time, mass, and environment. It employs a unique set of narrow-band filters on MOIRCS/Subaru to search for Ha emitters associated to the proto-clusters or in narrow redshift slices in the general field. We have shown not only filamentary/clumpy structures of all the proto-clusters but also very high star formation activities therein especially at z > 2. HST images from the CANDELS survey have revealed that nearly half of the Hα emitters in the field at z ∼ 2 have clumpy structures. Among them, “red dusty clumps” are preferentially found at or near the mass center of galaxies. Therefore, they are probably linked to the formation of bulge component. To explore physical states and the mode of star formation of those forming galaxies, we have started Gracias-ALMA project in full coordination with the Mahalo-Subaru project. We will resolve molecular gas contents and dusty star formation within these galaxies, and tell whether clumps are formed by gravitational instability of gas rich disks, and whether bulges are formed by clump migration or through galaxy-galaxy mergers.

Searching for massive, dusty starbursts offers the great opportunity to trace galaxy overdensities and thus the cosmic web in the distant universe. I will present our APEX-LABOCA 870 μm imaging of the protocluster field of the radio galaxy MRC1138–262 — the so-called Spiderweb Galaxy — at z = 2.16, uncovering a large number of so-called submm galaxies (SMGs). The number counts already indicate an excess of SMGs compared to blank fields. Based on an exquisite multi-wavelength dataset, I will show that a large fraction of these massive, dusty starbursts are physically associated with the protocluster at z = 2.16. Finally, I will discuss both the properties of this starburst overdensity and their individual members.

Our understanding of galaxy evolution has traditionally been driven by pre-selection of galaxies based on their broad-band continuum emission. This approach is potentially biased, in particular against gas-rich systems at high-redshift which may be dust-obscured. To overcome this limitation, we have recently concluded a blind CO survey at 3mm in a region of the Hubble Deep Field North using the IRAM Plateau de Bure Interferometer. Our study resulted in 1) the discovery of the redshift of the bright SMG HDF850.1 (z = 5.183); 2) the discovery of a bright line identified as CO(2-1) arising from a BzK galaxy at z = 1.785, and of other 6 CO lines associated with various galaxies in the field; 3) the detection of a few lines (presumably CO(3-2) at z ∼ 2) with no optical/NIR/MIR counterparts. These observational results allowed us to expand the parameter space of galaxy properties probed so far in high-z molecular gas studies. Most importantly, we could set first direct constraints on the cosmic evolution of the molecular gas content of the universe. The present study represents a first, fundamental step towards an unbiased census of molecular gas in ‘normal’ galaxies at high-z, a crucial goal of extragalactic astronomy in the ALMA era.

Cold gas streaming along the dark-matter filaments of the cosmic web is predicted to be the major provider of resources for disc buildup and star formation in massive galaxies in the early universe. We use hydrodynamical simulations to study to what extent these cold streams are traceable in the extended circum-galactic environment of galaxies via Ly alpha emission, Ly alpha absorption and selected low ionisation metal absorption lines. We predict the strength of the absorption signal produced by the streams and find that it is consistent with observations in high redshift galaxies. The characteristics of the Ly alpha emission of our simulated galaxies are similar in luminosity, morphology and extent to the observed Ly alpha blobs, with distinct kinematic features. We analyse the characteristics of the cold streams in simulations and present scaling relations for the amount of infall, its velocity, distribution and its clumpiness and compare our findings with observations.

The fraction of distant disks and mergers is still debated, while 3D-spectroscopy is revolutionizing the field. However its limited spatial resolution imposes a complimentary HST imagery and a robust analysis procedure. When applied to observations of IMAGES galaxies at z = 0.4-0.8, it reveals that half of the spiral progenitors were in a merger phase, 6 billion year ago. The excellent correspondence between methodologically-based classifications of morphologies and kinematics definitively probes a violent origin of disk galaxies as proposed by Hammer et al. (2005). Examination of nearby galaxy outskirts reveals fossil imprints of such ancient merger events, under the form of well organized stellar streams. Perhaps our neighbor, M31, is the best illustration of an ancient merger, which modeling in 2010 leads to predict the gigantic plane of satellites discovered by Ibata et al. (2013). There are still a lot of discoveries to be done until the ELT era, which will open an avenue for detailed and accurate 3D-spectroscopy of galaxies from the earliest epochs to the present.

A relation between the stellar mass M and the gas-phase metallicity Z of galaxies, the MZR, is observed up to higher redshifts. It is a matter of debate, however, if the SFR is a second parameter in the MZR. To explore this issue at z > 1, we used VLT-SINFONI near-infrared (NIR) spectroscopy of eight zCOSMOS galaxies at 1.3 < z < 1.4 to measure the strengths of four emission lines: Hβ, [OIII]λ5007, Hα, and [NII]λ6584, additional to [OII]λ3727 measured from VIMOS. We derive reliable O/H metallicities based on five lines, and also SFRs from extinction corrected Hα measurements. We find that the MZR of these star-forming galaxies at z ≈ 1.4 is lower than the local SDSS MZR by a factor of three to five, a larger change than reported in the literature using [NII]/Hα-based metallicities from individual and stacked spectra. Correcting N2-based O/Hs using recent results by Newman et al. (2014), also the larger FMOS sample at z ∼ 1.4 of Zahid et al. (2014) shows a similar evolution of the MZR like the zCOSMOS objects. These observations seem also in agreement with a non-evolving FMR using the physically motivated formulation of the FMR from Lilly et al. (2013).

Our new compilation of interferometric CO data suggests that nuclear and extended molecular gas disks are common in the final stages of mergers. Comparing the sizes of the molecular gas disk and gas mass fractions to early-type and late-type galaxies, about half of the sample show similar properties to early-type galaxies, which have compact gas disks and low gas mass fractions. We also find that sources with extended gas disks and large gas mass fractions may become disk-dominated galaxies.

To extend the molecular gas measurements to typical L* star-forming galaxies (SFGs) at z ∼ 1.5 − 3, we have observed CO emission for five strongly-lensed galaxies selected from the Herschel Lensing Survey. The combined sample of our L* SFGs with CO-detected SFGs at z >1 from the literature shows a large spread in star formation efficiency (SFE). We find that this spread in SFE is due to variations of several physical parameters, primarily the specific star formation rate, but also stellar mass and redshift. An increase of the molecular gas fraction (fgas) is observed from z ∼ 0.2 to z ∼ 1.2, followed by a quasi non-evolution toward higher redshifts, as found in earlier studies. We provide the first measure of fgas of z >1 SFGs at the low-stellar mass end between 109.4 < M∗/M⊙ < 109.9, which shows a clear fgas upturn.

We present recent results on Karl Jansky Very Large Array (JVLA) deep S-band (2-4 GHz) observation towards a protocluster 4C23.56 at redshift z ∼ 2.5. The protocluster 4C23.56 is known to have a significant over density (∼ 5 times) of star-burst galaxies selected to be Hα line-bright by a Subaru narrow band imaging. Now we have found 25 HAEs associated with the protocluster. These starburst HAEs are likely to become massive ellipticals at z = 0 in a cluster. Various other galaxy populations also reside in this field and the fact makes the field very unique as a tool to understand galaxy formation in a over dense region. Subsequent deep 1100-μm continuum surveys by the ASTE 10-m dish have discovered that several submillimeter bright galaxies (SMGs) coincide with HAEs, suggesting HAEs undergoing dusty starbursts. As star formation rates (SFRs) of HAEs might have been underestimated, we use radio being resistant to dust extinction. We investigate the correlation between SFR1.4 GHz and SFRHα for radio index α = 0.8 to see if the correlation holds for the sources and to check the number of dusty star forming galaxies. Our final results will allow us to evaluate quantitatively how the galaxy formation channel may be different under the condition of over-densities.

We investigate the environmental dependence of the mass-metallicty (MZ) relation and its connection to galaxy stellar structures and morphologies. In our studies, we analyze galaxies in massive clusters at z ∼ 0.4 from the CLASH (HST) and CLASH-VLT surveys and measure their gas metallicities, star-formation rates, stellar structures and morphologies. We establish the MZ relation for 90 cluster and 40 field galaxies finding a shift of ∼ − 0.3 dex in comparison to the local trends seen in SDSS for the majority of galaxies with logM < 10.5. We do not find significant differences of the distribution of 4 distinct morphological types that we introduce by our classification scheme (smooth, disc-like, peculiar, compact). Some variations between cluster and field galaxies in the MZ relation are visible at the high mass end. However, obvious trends for cluster specific interactions (enhancements or quenching of SFRs) are missing. In particular, galaxies with peculiar stellar structures that hold signs for galaxy interactions, are distributed in a similar way as disc-like galaxies - in SFRs, masses and O/H abundances. We further show that our sample falls around an extrapolation of the star-forming main sequence (the SFR-M∗ relation) at this redshift, indicating that emission-line selected samples do not have preferentially high star-formation rates (SFRs). However, we find that half of the high mass cluster members (M∗ > 1010M⊙) lie below the main sequence which corresponds to the higher mass objects that reach solar abundances in the MZ diagram.

One of the most characteristic features of galaxy clusters is the so-called “red sequence” (RS) of early-type galaxies. Since these galaxies are, in general, devoid of gas and dust, their red colors are mainly a consequence of their passive nature. However, the physical mechanisms responsible for quenching their star formation, thus originating the RS, are poorly understood. Environmental effects should play a significant role in the formation of the RS by transforming the observed galaxy properties from late to early-type ones. In this respect, we have initiated a KMOS program aimed at studying the kinematical structure of cluster galaxies at 0.8 < z < 1.7 in an effort to disentangle the physical mechanisms responsible for cluster galaxy evolution and the formation of the RS.

We present the KMOS (K-band Multi-Object Spectrograph) Cluster and VIRIAL (VLT IRIFU Absorption Line) Guaranteed Time Observation (GTO) programs. KMOS provides 24 arms each feeding an integral field unit (14×14 spaxels of 0.2″ pixels) for IZ, YJ, H and K band near infrared (NIR) medium resolution spectroscopy (R ∼ 3500). Targets are selected from a 7.2′ diameter patrol field. Ultra-deep spectroscopy of ∼ 80 early-type cluster galaxies (∼ 20hr on source) and ∼ 200 (∼ 10hr on source) early-type field galaxies at 1 < z < 2 will dramatically improve the situation at z > 1 for which measurements of stellar velocity dispersions and absorption indices are limited to a few, often relatively young passively evolving galaxies (e.g. Bezanson 2013). In ESO Periods P92 and P93, 15 nights worth of data has been collected for KMOS-Clusters and 6 nights for VIRIAL: this will be supplemented with more data in upcoming semesters. All galaxies have multiband HST imaging including existing or upcoming WFC3 IR imaging, providing stellar mass maps and sizes. Combined with our dispersion measurements, this will allow us to examine the fundamental plane and the dynamical mass of a large sample of z > 1 galaxies for the first time, for both cluster and field galaxies.

In the context of the first light of MUSE, Integral Field Unit (IFU) spectrograph of second generation installed recently at VLT, we compute mock IFU Lyman-alpha (lyα) observations of a virtual dwarf galaxy, to help understanding and interpreting forthcoming observations. This study is an extension of the work carried out in Verhamme et al. (2012), where we studied the spatially integrated lyα properties of a dwarf galaxy. With the same data, we now investigate the spatial variations of lyα spectra.

Each component of a galaxy plays its own unique role in regulating the galaxy's evolution. In order to understand how galaxies form and evolve, it is therefore crucial to study the distribution and properties of each of the various components, and the links between them, both radially and vertically. The latter is only possible in edge-on systems. We present the HEROES project, which aims to investigate the 3D structure of the interstellar gas, dust, stars and dark matter in a sample of 7 massive early-type spiral galaxies based on a multi-wavelength data set including optical, NIR, FIR and radio data.

The MIRAGE sample (Merging & isolated high-redshift AMR galaxies; Perret 2014, PhD dissertation; Perret et al. 2014, AA 562, 1) has been built in order to understand the contribution of the merger processes to the mass assembly in the MASSIV (Mass Assembly Survey with SINFONI in VVDS, Contini et al. 2012, AA 539, 91) sample. It consists of a sample of idealized simulations based on the RAMSES code; the initial conditions were designed to reproduce the physical properties of the most gas-rich young galaxies. The sample is composed of 20 simulations of mergers exploring the initial parameters of mass and orientation of the disks with a spatial resolution reaching 7 parsecs.

We performed 3D N-body/hydrodynamic simulations of local and high-z (z ∼ 2) star-forming galaxies (SFGs) to investigate the structure and kinematic properties of the different ISM phases (i.e., ionized, atomic, and molecular gases). We took into account, for the first time, a fully non-equilibrium radiative cooling by solving the non-equilibrium chemistries of atoms (H, He, C and O) and molecules (H2 and CO), as well as radiative heating, star formation, heating by HII region and supernova explosions.

A challenge in cosmological simulations is to formulate a physical model of star-formation (SF) and supernovae (SN) feedback which produces galactic outflows like that widely observed. In several models an outflow velocity (vout) and mass loading factor (η) are input to the sub-resolution recipe. We present results from our MUPPI model, which uses local properties of gas, and is able to develop galactic outflows whose properties correlate with global galaxy properties, consistent with observations; demonstrating a significant improvement in such work.

The properties of the host galaxies of quasi-stellar objects (QSOs) are essential for the understanding of the suspected coevolution of central supermassive black holes (BHs) and their host galaxies. In Busch et al. (2014), we present a study of 20 low-luminosity type-1 QSOs (LLQSO; Busch et al.2012) that have been selected from the Hamburg/ESO survey for bright UV-excess QSOs (z ≤ 0.06). Performing careful decomposition of deep near-infrared J,H,K images, we found that the observed sources do not follow published MBH – Lbulge relations for inactive galaxies, supporting similar results found for type-1 AGN in the optical. This can be explained by overluminous bulges with very young stellar populations or undermassive black holes that are observed in a phase of growth. We use 3d-spectroscopy in the optical and near-infrared as a powerful tool to analyze gas and stellar kinematics, determine gas masses, star formation rate, trace underlying stellar continuum, etc. (e.g., Smajić et al.2014) and thereby constrain possible evolution scenarios. The results will be interpreted in the context of galaxy evolution and particularly the still unknown role of the AGN in this process. Here, we show first results for HE 1029-1831.

We present a new method for the detection and characterization of large scale expansion in galaxy discs based on Hα Fabry-Perot spectroscopy, taking advantage of the high spatial and velocity resolution of our instrument (GHαFaS). The method analyses multi-peaked emission line profiles to find expansion along the line of sight on a pixel-by-pixel basis. At this stage we have centred our attention on the large scale structures of expansive gas which show a coherent gradient of velocities from their centres as a result of both bubble shape and projection effect. The results show a wide range of expansion velocities in these superbubbles, ranging from 30-150 km/s, with the expected trend of finding the higher velocities in the more violent areas of the galaxies. We have applied the technique to the Antennae and M83, obtaining spectacular results, and used these to investigate to what extent kinematically derived ages can be found and used to characterize the ages of their massive star clusters.

Superbubbles and large scale expansion in galaxies are important indicators of activity in galaxies: they are formed in starbursts and around active nuclei. Superbubbles can be used to give information about the star-forming region which produced them. We present in-depth results of our study of kinematically detected superbubbles using a method based on Fabry-Perot spectroscopy, which allows us to map regions of expansion across the entire disk of a galaxy. Three objects have been selected for this poster based on the interest of the results they show: two interacting galaxies, the Antennae and Arp270, at different stages of galaxy interaction, and the more isolated galaxy M83. We present the kinematic expansion maps, as well as a census of detected superbubbles and a dynamical study of their properties.