Cosmological simulations predict that the Universe contains a network of intergalactic gas filaments, within which galaxies form and evolve. However, the faintness of any emission from these ...filaments has limited tests of this prediction. We report the detection of rest-frame ultraviolet Lyman-α radiation from multiple filaments extending more than one megaparsec between galaxies within the SSA22 protocluster at a redshift of 3.1. Intense star formation and supermassive black-hole activity is occurring within the galaxies embedded in these structures, which are the likely sources of the elevated ionizing radiation powering the observed Lyman-α emission. Our observations map the gas in filamentary structures of the type thought to fuel the growth of galaxies and black holes in massive protoclusters.
We compare the kinetic energy and momentum injection rates from intense star formation, bolometric AGN radiation, and radio jets with the kinetic energy and momentum observed in the warm ionized gas ...in 24 powerful radio galaxies at z ~ 2. These galaxies are among our best candidates for being massive galaxies near the end of their active formation period, when intense star formation, quasar activity, and powerful radio jets all co-exist. All galaxies have VLT/SINFONI imaging spectroscopy of the rest-frame optical line emission, showing extended emission-line regions with large velocity offsets (up to 1500 km s-1) and line widths (typically 800–1000 km s-1) consistent with very turbulent, often outflowing gas. As part of the HeRGÉ sample, they also have FIR estimates of the star formation and quasar activity obtained with Herschel/PACS and SPIRE, which enables us to measure the relative energy and momentum release from each of the three main sources of feedback in massive, star-forming AGN host galaxies during their most rapid formation phase. We find that star formation falls short by factors 10−1000 of providing the energy and momentum necessary to power the observed gas kinematics. The obscured quasars in the nuclei of these galaxies provide enough energy and momentum in about half of the sample, however, only if both are transferred to the gas relatively efficiently. We compare with theoretical and observational constraints on the efficiency of the energy and momentum transfer from jet and AGN radiation, which favors the radio jets as main drivers of the gas kinematics.
We present Multi Unit Spectroscopic Explorer (MUSE) integral field unit spectroscopic observations of the ∼150 kpc Lyα halo around the z = 4.1 radio galaxy TN J1338−1942. This 9-h observation maps ...the full two-dimensional kinematics of the Lyα emission across the halo, which shows a velocity gradient of Δv ∼ 700 km s−1 across 150 kpc in projection, and also identified two absorption systems associated with the Lyα emission from the radio galaxy. Both absorbers have high covering fractions (∼1) spanning the full ∼150 × 80 kpc2 extent of the halo. The stronger and more blueshifted absorber (Δv ∼ −1200 km s−1 from the systemic) has dynamics that mirror that of the underlying halo emission and we suggest that this high column material (n(H i) ∼ 1019.4 cm−2), which is also seen in C iv absorption, represents an outflowing shell that has been driven by the active galactic nuclei (AGN) or the star formation within the galaxy. The weaker (n(H i) ∼ 1014 cm−2) and less blueshifted (Δv ∼ −500 km s−1) absorber most likely represents material in the cavity between the outflowing shell and the Lyα halo. We estimate that the mass in the shell must be ∼1010 M⊙ – a significant fraction of the interstellar medium from a galaxy at z = 4. The large scales of these coherent structures illustrate the potentially powerful influence of AGN feedback on the distribution and energetics of material in their surroundings. Indeed, the discovery of high-velocity (∼1000 km s−1), group-halo-scale (i.e. >150 kpc) and mass-loaded winds in the vicinity of the central radio source is in agreement with the requirements of models that invoke AGN-driven outflows to regulate star formation and black hole growth in massive galaxies.
We observed Hubble Deep Field South with the new panoramic integral-field spectrograph MUSE that we built and have just commissioned at the VLT. The data cube resulting from 27 h of integration ...covers one arcmin2 field of view at an unprecedented depth with a 1σ emission-line surface brightness limit of 1 × 10-19 erg s-1 cm-2 arcsec-2, and contains ~90 000 spectra. We present the combined and calibrated data cube, and we performed a first-pass analysis of the sources detected in the Hubble Deep Field South imaging. We measured the redshifts of 189 sources up to a magnitude I814 = 29.5, increasing the number of known spectroscopic redshifts in this field by more than an order of magnitude. We also discovered 26 Lyα emitting galaxies that are not detected in the HST WFPC2 deep broad-band images. The intermediate spectral resolution of 2.3 Å allows us to separate resolved asymmetric Lyα emitters, O ii3727 emitters, and C iii1908 emitters, and the broad instantaneous wavelength range of 4500 Å helps to identify single emission lines, such as O iii5007, Hβ, and Hα, over a very wide redshift range. We also show how the three-dimensional information of MUSE helps to resolve sources that are confused at ground-based image quality. Overall, secure identifications are provided for 83% of the 227 emission line sources detected in the MUSE data cube and for 32% of the 586 sources identified in the HST catalogue. The overall redshift distribution is fairly flat to z = 6.3, with a reduction between z = 1.5 to 2.9, in the well-known redshift desert. The field of view of MUSE also allowed us to detect 17 groups within the field. We checked that the number counts of O ii3727 and Lyα emitters are roughly consistent with predictions from the literature. Using two examples, we demonstrate that MUSE is able to provide exquisite spatially resolved spectroscopic information on the intermediate-redshift galaxies present in the field. Thisunique data set can be used for a wide range of follow-up studies. We release the data cube, the associated products, and the source catalogue with redshifts, spectra, and emission-line fluxes.
Context.
Here we describe a simple, efficient, and most importantly fully operational point-spread-function (PSF)-reconstruction approach for laser-assisted ground layer adaptive optics (GLAO) in the ...frame of the Multi Unit Spectroscopic Explorer (MUSE) wide field mode.
Aims.
Based on clear astrophysical requirements derived by the MUSE team and using the functionality of the current ESO Adaptive Optics Facility we aim to develop an operational PSF-reconstruction (PSFR) algorithm and test it both in simulations and using on-sky data.
Methods.
The PSFR approach is based on a Fourier description of the GLAO correction to which the specific instrumental effects of MUSE wide field mode (pixel size, internal aberrations, etc.) have been added. It was first thoroughly validated with full end-to-end simulations. Sensitivity to the main atmospheric and AO system parameters was analysed and the code was re-optimised to account for the sensitivity found. Finally, the optimised algorithm was tested and commissioned using more than one year of on-sky MUSE data.
Results.
We demonstrate with an on-sky data analysis that our algorithm meets all the requirements imposed by the MUSE scientists, namely an accuracy better than a few percent on the critical PSF parameters including full width at half maximum and global PSF shape through the kurtosis parameter of a Moffat function.
Conclusions.
The PSFR algorithm is publicly available and is used routinely to assess the MUSE image quality for each observation. It can be included in any post-processing activity which requires knowledge of the PSF.
X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope (VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the ...Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 to 2500 nm. It is designed to maximize the sensitivity in this spectral range through dichroic splitting in three arms with optimized optics, coatings, dispersive elements and detectors. It operates at intermediate spectral resolution (R ~ 4000−17 000, depending on wavelength and slit width) with fixed échelle spectral format (prism cross-dispersers) in the three arms. It includes a 1.8″ × 4″ integral field unit as an alternative to the 11′′ long slits. A dedicated data reduction package delivers fully calibrated two-dimensional and extracted spectra over the full wavelength range. We describe the main characteristics of the instrument and present its performance as measured during commissioning, science verification and the first months of science operations.
High-redshift radio galaxies present signs of both star formation and AGN activity, making them ideal candidates to investigate the connection and coevolution of AGN and star formation in the ...progenitors of present-day massive galaxies. We make use of a sample of 11 powerful radio galaxies spanning 1 <z< 4 which have complete coverage of their spectral energy distribution (SED) from UV to FIR wavelengths. Using Herschel data, we disentangle the relative contribution of the AGN and star formation by combining the galaxy evolution code PÉGASE.3 with an AGN torus model. We find that three components are necessary to reproduce the observed SEDs: an evolved and massive stellar component, a submm bright young starburst, and an AGN torus. We find that powerful radio galaxies form at very high-redshift, but experience episodic and important growth at 1 <z< 4 as the mass of the associated starburst varies from 5 to 50% of the total mass of the system. The properties of star formation differ from source to source, indicating no general trend of the star formation properties in the most infrared luminous high-redshift radio galaxies and no correlation with the AGN bolometric luminosity. Moreover, we find that AGN scattered light have a very limited impact on broad-band SED fitting on our sample. Finally, our analysis also suggests a wide range in origins for the observed star formation,which we partially constrain for some sources.
Abstract
We present a MUSE (Multi-Unit Spectroscopic Explorer) and KMOS (K-band Multi-Object Spectrograph) dynamical study 405 star-forming galaxies
at redshift z = 0.28–1.65 (median redshift
...$\bar{z}$
= 0.84). Our sample is representative of the star-forming ‘main sequence’, with star formation rates of SFR = 0.1–30 M⊙ yr−1 and stellar masses M
⋆ = 108–1011 M⊙. For 49 ± 4 per cent of our sample, the dynamics suggest rotational support, 24 ± 3 per cent are unresolved systems and 5 ± 2 per cent appear to be early-stage major mergers with components on 8–30 kpc scales. The remaining 22 ± 5 per cent appear to be dynamically complex, irregular (or face-on systems). For galaxies whose dynamics suggest rotational support, we derive inclination-corrected rotational velocities and show that these systems lie on a similar scaling between stellar mass and specific angular momentum as local spirals with j
⋆ = J/
$M_\star \propto M_\star ^{2/3}$
but with a redshift evolution that scales as j
⋆ ∝ M
$_\star ^{2/3}(1+z)^{-1}$
. We also identify a correlation between specific angular momentum and disc stability such that galaxies with the highest specific angular momentum (log(j
⋆/M
$_\star ^{2/3}$
) > 2.5) are the most stable, with Toomre Q = 1.10 ± 0.18, compared to Q = 0.53 ± 0.22 for galaxies with log(j
⋆/M
$_\star ^{2/3}$
) < 2.5. At a fixed mass, the Hubble Space Telescope morphologies of galaxies with the highest specific angular momentum resemble spiral galaxies, whilst those with low specific angular momentum are morphologically complex and dominated by several bright star-forming regions. This suggests that angular momentum plays a major role in defining the stability of gas discs: at z ∼ 1, massive galaxies that have discs with low specific angular momentum are globally unstable, clumpy and turbulent systems. In contrast, galaxies with high specific angular momentum have evolved into stable discs with spiral structure where star formation is a local (rather than global) process.
Context. This paper presents the results obtained with the Multi Unit Spectroscopic Explorer (MUSE) for the core of the lensing cluster Abell 1689, as part of MUSE’s commissioning at the ESO Very ...Large Telescope. Aims. Integral-field observations with MUSE provide a unique view of the central 1 × 1 arcmin2 region at intermediate spectral resolution in the visible domain, allowing us to conduct a complete census of both cluster galaxies and lensed background sources. Methods. We performed a spectroscopic analysis of all sources found in the MUSE data cube. Two hundred and eighty-two objects were systematically extracted from the cube based on a guided-and-manual approach. We also tested three different tools for the automated detection and extraction of line emitters. Cluster galaxies and lensed sources were identified based on their spectral features. We investigated the multiple-image configuration for all known sources in the field. Results. Previous to our survey, 28 different lensed galaxies displaying 46 multiple images were known in the MUSE field of view, most of them were detected through photometric redshifts and lensing considerations. Of these, we spectroscopically confirm 12 images based on their emission lines, corresponding to 7 different lensed galaxies between z = 0.95 and 5.0. In addition, 14 new galaxies have been spectroscopically identified in this area thanks to MUSE data, with redshifts ranging between 0.8 and 6.2. All background sources detected within the MUSE field of view correspond to multiple-imaged systems lensed by A1689. Seventeen sources in total are found at z ≥ 3 based on their Lyman-α emission, with Lyman-α luminosities ranging between 40.5 ≲ log (Lyα) ≲ 42.5 after correction for magnification. This sample is particularly sensitive to the slope of the luminosity function toward the faintest end. The density of sources obtained in this survey is consistent with a steep value of α ≤ −1.5, although this result still needs further investigation. Conclusions. These results illustrate the efficiency of MUSE in characterizing lensing clusters on one hand and in studying faint and distant populations of galaxies on the other hand. In particular, our current survey of lensing clusters is expected to provide a unique census of sources responsible for the reionization in a representative volume at z ~ 4−7.
ABSTRACT
We present Very Large Telescope/Spectrograph for INtegral Field Observations in the Near Infrared (VLT/SINFONI) observations of 35 quasars at 2.1 < z < 3.2, the majority of which were ...selected from the Clusters Around Radio-Loud AGN (CARLA) survey. CARLA quasars have large C iv-based black hole masses (MBH > 109 M⊙) and powerful radio emission ($P_{500\, \rm MHz}$ > 27.5 W Hz−1). We estimate H α-based MBH, finding a scatter of 0.35 dex compared to C iv. We evaluate several recipes for correcting C iv-based masses, which reduce the scatter to 0.24 dex. The radio power of the radio-loud quasars is at most weakly correlated with the interconnected quantities H αwidth, L5100, and MBH, suggesting that it is governed by different physical processes. However, we do find a strong inverse correlation between C iv blueshift and radio power linked to higher Eddington ratios and L5100. Under standard assumptions, the black hole (BH) growth time is longer than the cosmic age for many CARLA quasars, suggesting that they must have experienced more efficient growth in the past. If these BHs were growing from seeds since the epoch of reionization, it is possible that they grew at the Eddington limit like the quasars at z ∼ 6–7, and then continued to grow at the reduced rates observed until z ∼ 2–3. Finally, we study the relation between MBH and environment, finding a weak positive correlation between MBH and galaxydensity measured by CARLA.
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