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Early galaxy revealed in Hubble data An ultra-deep search through the full Hubble Ultra Deep Field data set has uncovered a galaxy with a redshift of z ≈ 10, equivalent to an age of only 500 million years after the Big Bang. The data also provide strong constraints on the volume density of galaxies — and hence the star formation rate — at this time. The authors conclude that the star formation rate increased by a factor of ten in the time between z ≈ 10 and z ≈ 8, implying that this period in the heart of the reionization epoch was one in which galaxies were evolving very rapidly. Here, the full two-year Hubble Ultra Deep Field (HUDF09) data are used to conduct an ultra-deep search for z ≈10 galaxies in the heart of the reionization epoch, only 500 million years after the Big Bang. One possible z ≈10 galaxy candidate is found. It is also shown that regardless of source detections, the star formation rate density is much smaller (∼10%) at this time than it is just ∼200 million years later at z ≈8. The 100–200 million years prior to z ≈10 is clearly a crucial phase in the assembly of the earliest galaxies. Searches for very-high-redshift galaxies over the past decade have yielded a large sample of more than 6,000 galaxies existing just 900–2,000 million years (Myr) after the Big Bang (redshifts 6 >  z  > 3; ref. 1 ). The Hubble Ultra Deep Field (HUDF09) data 2 , 3 have yielded the first reliable detections of z  ≈ 8 galaxies 3 , 4 , 5 , 6 , 7 , 8 , 9 that, together with reports of a γ-ray burst at z  ≈ 8.2 (refs 10 , 11 ), constitute the earliest objects reliably reported to date. Observations of z  ≈ 7–8 galaxies suggest substantial star formation at z  > 9–10 (refs 12 , 13 ). Here we use the full two-year HUDF09 data to conduct an ultra-deep search for z  ≈ 10 galaxies in the heart of the reionization epoch, only 500 Myr after the Big Bang. Not only do we find one possible z  ≈ 10 galaxy candidate, but we show that, regardless of source detections, the star formation rate density is much smaller (∼10%) at this time than it is just ∼200 Myr later at z  ≈ 8. This demonstrates how rapid galaxy build-up was at z  ≈ 10, as galaxies increased in both luminosity density and volume density from z  ≈ 10 to z  ≈ 8. The 100–200 Myr before z  ≈ 10 is clearly a crucial phase in the assembly of the earliest galaxies.

The Cosmic Evolution Survey (COSMOS) has become a cornerstone of extragalactic astronomy. Since the last public catalog in 2015, a wealth of new imaging and spectroscopic data have been collected in the COSMOS field. This paper describes the collection, processing, and analysis of these new imaging data to produce a new reference photometric redshift catalog. Source detection and multiwavelength photometry are performed for 1.7 million sources across the 2 deg2 of the COSMOS field, ∼966,000 of which are measured with all available broadband data using both traditional aperture photometric methods and a new profile-fitting photometric extraction tool, The Farmer, which we have developed. A detailed comparison of the two resulting photometric catalogs is presented. Photometric redshifts are computed for all sources in each catalog utilizing two independent photometric redshift codes. Finally, a comparison is made between the performance of the photometric methodologies and of the redshift codes to demonstrate an exceptional degree of self-consistency in the resulting photometric redshifts. The i < 21 sources have subpercent photometric redshift accuracy and even the faintest sources at 25 < i < 27 reach a precision of 5%. Finally, these results are discussed in the context of previous, current, and future surveys in the COSMOS field. Compared to COSMOS2015, it reaches the same photometric redshift precision at almost one magnitude deeper. Both photometric catalogs and their photometric redshift solutions and physical parameters will be made available through the usual astronomical archive systems (ESO Phase 3, IPAC-IRSA, and CDS).

The Near-Infrared Spectrograph (NIRSpec) is one of the four focal plane instruments on the James Webb Space Telescope. In this paper, we summarize the in-orbit performance of NIRSpec, as derived from data collected during its commissioning campaign and the first few months of nominal science operations. More specifically, we discuss the performance of some critical hardware components such as the two NIRSpec Hawaii-2RG detectors, wheel mechanisms, and the microshutter array. We also summarize the accuracy of the two target acquisition procedures used to accurately place science targets into the slit apertures, discuss the current status of the spectrophotometric and wavelength calibration of NIRSpec spectra, and provide the “as measured” sensitivity in all NIRSpec science modes. Finally, we point out a few important considerations for the preparation of NIRSpec science programs.

The Near-Infrared Spectrograph (NIRSpec) is one of the four focal plane instruments on the James Webb Space Telescope. In this paper, we summarize the in-orbit performance of NIRSpec, as derived from data collected during its commissioning campaign and the first few months of nominal science operations. More specifically, we discuss the performance of some critical hardware components such as the two NIRSpec Hawaii-2RG detectors, wheel mechanisms, and the microshutter array. We also summarize the accuracy of the two target acquisition procedures used to accurately place science targets into the slit apertures, discuss the current status of the spectrophotometric and wavelength calibration of NIRSpec spectra, and provide the “as measured” sensitivity in all NIRSpec science modes. Finally, we point out a few important considerations for the preparation of NIRSpec science programs.

Robust evidence to direct management of pregnant women with mild hypertensive disease at term is scarce. We investigated whether induction of labour in women with a singleton pregnancy complicated by gestational hypertension or mild pre-eclampsia reduces severe maternal morbidity. We undertook a multicentre, parallel, open-label randomised controlled trial in six academic and 32 non-academic hospitals in the Netherlands between October, 2005, and March, 2008. We enrolled patients with a singleton pregnancy at 36–41 weeks' gestation, and who had gestational hypertension or mild pre-eclampsia. Participants were randomly allocated in a 1:1 ratio by block randomisation with a web-based application system to receive either induction of labour or expectant monitoring. Masking of intervention allocation was not possible. The primary outcome was a composite measure of poor maternal outcome—maternal mortality, maternal morbidity (eclampsia, HELLP syndrome, pulmonary oedema, thromboembolic disease, and placental abruption), progression to severe hypertension or proteinuria, and major post-partum haemorrhage (>1000 mL blood loss). Analysis was by intention to treat and treatment effect is presented as relative risk. This study is registered, number ISRCTN08132825. 756 patients were allocated to receive induction of labour (n=377 patients) or expectant monitoring (n=379). 397 patients refused randomisation but authorised use of their medical records. Of women who were randomised, 117 (31%) allocated to induction of labour developed poor maternal outcome compared with 166 (44%) allocated to expectant monitoring (relative risk 0·71, 95% CI 0·59–0·86, p<0·0001). No cases of maternal or neonatal death or eclampsia were recorded. Induction of labour is associated with improved maternal outcome and should be advised for women with mild hypertensive disease beyond 37 weeks' gestation. ZonMw.

The evolution of galaxies is likely to be complex, involving mergers, starbursts, and other dramatic changes in morphology and luminosity. The measurement of the evolution of the mass function of galaxies is therefore essential. This can be accomplished by measuring the evolution of the mass-to-light ratios of galaxies as a function of redshift. The Fundamental Plane relation is uniquely suited to measure the evolution of the mass-to-light ratio of early-type galaxies. We show that the evolution depends sensitively on cosmology and star-formation history. We present results on the evolution of the mass-to-light ratio from the Fundamental Plane out to z = 0.83. The early-type galaxies in clusters follow a well-defined relation out the highest redshift. The mass-to-light evolution is very slow, and implies a high mean stellar age in an open universe. One of the main uncertainties in the interpretation is morphological evolution. If the youngest early types at low redshift appear as other morphological types at high redshift, then the study of early-type galaxies at high redshifts will produce biased results. We discuss the effects of this 'progenitor bias'. We show evidence for significant morphological evolution for all early types (elliptical and S0 galaxies). We find a high fraction of mergers in MS 1054-03, comparable with the fraction of ellipticals. Furthermore, the total fraction of early types in rich clusters decreases from z = 0 to z = 0.83. These results suggest that the set of early types is not a closed set, but evolving. The effects on the derived evolution of the mass-to-light ratio is relatively small, due to the small scatter. The next step will be to extend these studies to high redshift clusters, and to the field. This work can provide very strong constraints on the mass evolution of galaxies.

Searches for very-high-redshift galaxies over the past decade have yielded a large sample of more than 6,000 galaxies existing just 900-2,000million years (Myr) after the Big Bang (redshifts 6>z>3; ref. 1). The Hubble Ultra Deep Field (HUDF09) data have yielded the first reliable detections of z approximately 8 galaxies that, together with reports of a gamma -ray burst at z approximately 8.2 (refs 10, 11), constitute the earliest objects reliably reported to date. Observations of z approximately 7-8 galaxies suggest substantial star formation at z>9-10 (refs 12, 13). Here we use the full two-year HUDF09 data to conduct an ultra-deep search for z approximately 10 galaxies in the heart of the reionization epoch, only 500Myr after the Big Bang. Not only do we find one possible z approximately 10 galaxy candidate, but we show that, regardless of source detections, the star formation rate density is much smaller (10%) at this time than it is just 200Myr later at z approximately 8. This demonstrates how rapid galaxy build-up was at z approximately 10, as galaxies increased in both luminosity density and volume density from z approximately 10 to z approximately 8. The 100-200Myr before z approximately 10 is clearly a crucial phase in the assembly of the earliest galaxies.

There is significant evidence that galaxy evolution is a complex process, in which mass accretion, mergers, and star bursts play an important role. This complex evolution adds significant freedom to the modeling of observations of high-redshift galaxies. Additional constraints are necessary.Such constraints may come from measurements of circular velocities, or velocity dispersions of galaxies at intermediate redshift. The first observations of central velocity dispersions are presented for galaxies in the rich cluster Abell 665 at z= 0.18. Full curves of radial velocity, and velocity dispersion of cluster members are presented. The measurements result in a well-defined Faber-Jackson relation for the red cluster members. A blue galaxy is lying 2.2 mag off the relation, and has an \"E+ A\" spectrum. This \"Butcher-Oemler\" galaxy is rotating rapidly, which is indicative of a strong disk. The observations show that measurements of central velocity dispersions are possible with current telescope capabilities.Observations at higher redshifts will lead to new constraints on both galaxy evolution and cosmology.

The Fundamental plane provides a sensitive tool to measure the change in the M/L ratio of early type galaxies with redshift. The evolution of the M/L ratio is a function of the star formation history. It depends on the IMF, the formation redshift, and cosmology. Some model examples are shown, and a first result on the cluster Abell 665 at z=0.18 is given. The measurements confirm the cosmological surface brightness dimming, and imply an evolution of the (red) L/M ratio (1 + z)^sup 1.8±0.7^. More data are needed to extend this result to higher redshifts, and to test the underlying assumptions.[PUBLICATION ABSTRACT]

We describe the scientific motivations, the mission concept and the instrumentation of SPACE, a class-M mission proposed for concept study at the first call of the ESA Cosmic-Vision 2015–2025 planning cycle. SPACE aims to produce the largest three-dimensional evolutionary map of the Universe over the past 10 billion years by taking near-IR spectra and measuring redshifts for more than half a billion galaxies at 0 < z < 2 down to AB~23 over 3π sr of the sky. In addition, SPACE will also target a smaller sky field, performing a deep spectroscopic survey of millions of galaxies to AB~26 and at 2 < z < 10 +. These goals are unreachable with ground-based observations due to the ≈500 times higher sky background (see e.g. Aldering, LBNL report number LBNL-51157, 2001). To achieve the main science objectives, SPACE will use a 1.5 m diameter Ritchey-Chretien telescope equipped with a set of arrays of Digital Micro-mirror Devices covering a total field of view of 0.4 deg2, and will perform large-multiplexing multi-object spectroscopy (e.g. ≈6000 targets per pointing) at a spectral resolution of R~400 as well as diffraction-limited imaging with continuous coverage from 0.8 to 1.8 μm. Owing to the depth, redshift range, volume coverage and quality of its spectra, SPACE will reveal with unique sensitivity most of the fundamental cosmological signatures, including the power spectrum of density fluctuations and its turnover. SPACE will also place high accuracy constraints on the dark energy equation of state parameter and its evolution by measuring the baryonic acoustic oscillations imprinted when matter and radiation decoupled, the distance-luminosity relation of cosmological supernovae, the evolution of the cosmic expansion rate, the growth rate of cosmic large-scale structure, and high-z galaxy clusters. The datasets from the SPACE mission will represent a long lasting legacy for the whole astronomical community whose data will be mined for many years to come.