Fast molecular outflow from a dusty star-forming galaxy in the early Universe.

Galaxies grow inefficiently, with only a small percentage of the available gas converted into stars each free-fall time. Feedback processes, such as outflowing winds driven by radiation pressure, supernovae, or supermassive black hole accretion, can act to halt star formation if they heat or expel the gas supply. We report a molecular outflow launched from a dust-rich star-forming galaxy at redshift 5.3, 1 billion years after the Big Bang. The outflow reaches velocities up to 800 kilometers per second relative to the galaxy, is resolved into multiple clumps, and carries mass at a rate within a factor of 2 of the star formation rate. Our results show that molecular outflows can remove a large fraction of the gas available for star formation from galaxies at high redshift.

Author Correction: A massive core for a cluster of galaxies at a redshift of 4.3.

Change history: In this Letter, the Acknowledgements section should have included the following sentence: "The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.". This omission has been corrected online.

A massive core for a cluster of galaxies at a redshift of 4.3.

Massive galaxy clusters have been found that date to times as early as three billion years after the Big Bang, containing stars that formed at even earlier epochs1-3. The high-redshift progenitors of these galaxy clusters-termed 'protoclusters'-can be identified in cosmological simulations that have the highest overdensities (greater-than-average densities) of dark matter4-6. Protoclusters are expected to contain extremely massive galaxies that can be observed as luminous starbursts 7 . However, recent detections of possible protoclusters hosting such starbursts8-11 do not support the kind of rapid cluster-core formation expected from simulations 12 : the structures observed contain only a handful of starbursting galaxies spread throughout a broad region, with poor evidence for eventual collapse into a protocluster. Here we report observations of carbon monoxide and ionized carbon emission from the source SPT2349-56. We find that this source consists of at least 14 gas-rich galaxies, all lying at redshifts of 4.31. We demonstrate that each of these galaxies is forming stars between 50 and 1,000 times more quickly than our own Milky Way, and that all are located within a projected region that is only around 130 kiloparsecs in diameter. This galaxy surface density is more than ten times the average blank-field value (integrated over all redshifts), and more than 1,000 times the average field volume density. The velocity dispersion (approximately 410 kilometres per second) of these galaxies and the enormous gas and star-formation densities suggest that this system represents the core of a cluster of galaxies that was already at an advanced stage of formation when the Universe was only 1.4 billion years old. A comparison with other known protoclusters at high redshifts shows that SPT2349-56 could be building one of the most massive structures in the Universe today.

Galaxy growth in a massive halo in the first billion years of cosmic history.

According to the current understanding of cosmic structure formation, the precursors of the most massive structures in the Universe began to form shortly after the Big Bang, in regions corresponding to the largest fluctuations in the cosmic density field. Observing these structures during their period of active growth and assembly-the first few hundred million years of the Universe-is challenging because it requires surveys that are sensitive enough to detect the distant galaxies that act as signposts for these structures and wide enough to capture the rarest objects. As a result, very few such objects have been detected so far. Here we report observations of a far-infrared-luminous object at redshift 6.900 (less than 800 million years after the Big Bang) that was discovered in a wide-field survey. High-resolution imaging shows it to be a pair of extremely massive star-forming galaxies. The larger is forming stars at a rate of 2,900 solar masses per year, contains 270 billion solar masses of gas and 2.5 billion solar masses of dust, and is more massive than any other known object at a redshift of more than 6. Its rapid star formation is probably triggered by its companion galaxy at a projected separation of 8 kiloparsecs. This merging companion hosts 35 billion solar masses of stars and has a star-formation rate of 540 solar masses per year, but has an order of magnitude less gas and dust than its neighbour and physical conditions akin to those observed in lower-metallicity galaxies in the nearby Universe. These objects suggest the presence of a dark-matter halo with a mass of more than 100 billion solar masses, making it among the rarest dark-matter haloes that should exist in the Universe at this epoch.

The ocular pigmentary disturbance of human Chédiak-Higashi syndrome. A comparative light- and electron-microscopic study and review of the literature.

The ultrastructure of the ocular pigment abnormality of human Chédiak-Higashi syndrome is described. The presence of giant abnormal melanosomes, probably the end result of the fusion of smaller abnormal organelles, was the most striking pathologic finding. This defect involved both optic cup and neural crest-derived melanocytes; the former were affected more severely. Giant lysosome-like organelles were also observed.

Bronchiolo-alveolar carcinoma with nodal metastases. An ultrastructural study.

A case of bronchiolo-alveolar carcinoma of the lung was studied by light and electron microscopy. Type II granular pneumocytes were seen in the lymph node metastases of the tumor, a finding not reported previously. We feel that the presence of these cells in metastatic foci indicates their neoplastic nature, and provides evidence that bronchiolo-alveolar carcinoma arises from type II cells.

The renal pathology of Chediak-Higashi disease: usefulness of the urinary sediment as a confirmatory diagnostic test.

The presence of large cytoplasmic inclusions, thought to be abnormal lysosomes, seems to be the cytological hallmark of Chediak-Higashi disease in both humans and animals. This cell anomaly, originally reported in the leukocytes, is also present in various tissue cells, including kidneys. In the patient described, the abnormal inclusions were identified in renal cells of the urinary sediment. Thus, urine could provide a convenient source of diagnostic material in patients with Chediak-Higashi disease. In addition, the ultrastructure of these inclusions is described for the first time in human renal tissue.

Problems in the development of a clinically oriented program in electron microscopy.

The educational, organizational, and fiscal aspects of electron microscopy are discussed.. with emphais on the desirability of making electron microscopy an integral part of the formal training of residents in pathology and of the overall educational program of the medical staff. The rapidity of feedback of information from the pathologist to the clinician is stressed. The number of specimens processed and the variety of tissues submitted for electron microscopy can be regulated by the pathologist but should reflect the particular strength of the hospital or its department of pathology. The organization of the electron microscopy facility, its funding, and sharing of the electron microscopy program in the local community of clinical scientists are discussed

Whipple's disease. An example of the value of the electron microscope in diagnosis, follow-up, and correlation of a pathologic process.

Two cases of Whipple's disease were followed by electron microscopic study of periodic peroral suction biopsy specimens of small intestine to show the presence and disappearance of the interstitial lamina proprial organisms, the sequential changes of the macrophages, and the return to normal leukocytic population of the lamina propria following prolonged treatment with tetracycline. The value of electron microscopy in the detection of small numbers of micro-organisms is demonstrated. Ultrastructural study is the most efficient method of demonstrating the presence of diagnostic micro-organisms, measuring the adequacy of treatment, and identifying possible early reactivation of infection.