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The extreme astrophysical processes and conditions that characterize the early Universe are expected to result in young galaxies that are dynamically different from those observed today1-5. This is because the strong effects associated with galaxy mergers and supernova explosions would lead to most young star-forming galaxies being dynamically hot, chaotic and strongly unstable1,2. Here we report the presence of a dynamically cold, but highly star-forming, rotating disk in a galaxy at redshift6 z = 4.2, when the Universe was just 1.4 billion years old. Galaxy SPT-S J041839-4751.9 is strongly gravitationally lensed by a foreground galaxy at z = 0.263, and it is a typical dusty starburst, with global star-forming7 and dust properties8 that are in agreement with current numerical simulations9 and observations10. Interferometric imaging at a spatial resolution of about 60 parsecs reveals a ratio of rotational to random motions of 9.7 ± 0.4, which is at least four times larger than that expected from any galaxy evolution model at this epoch1-5 but similar to the ratios of spiral galaxies in the local Universe11. We derive a rotation curve with the typical shape of nearby massive spiral galaxies, which demonstrates that at least some young galaxies are dynamically akin to those observed in the local Universe, and only weakly affected by extreme physical processes.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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The mass function of dwarf satellite galaxies that are observed around Local Group galaxies differs substantially from simulations based on cold dark matter: the simulations predict many more dwarf galaxies than are seen. The Local Group, however, may be anomalous in this regard. A massive dark satellite in an early-type lens galaxy at a redshift of 0.222 was recently found using a method based on gravitational lensing, suggesting that the mass fraction contained in substructure could be higher than is predicted from simulations. The lack of very low-mass detections, however, prohibited any constraint on their mass function. Here we report the presence of a (1.9 ± 0.1) × 10(8) M dark satellite galaxy in the Einstein ring system JVAS B1938+666 (ref. 11) at a redshift of 0.881, where M denotes the solar mass. This satellite galaxy has a mass similar to that of the Sagittarius galaxy, which is a satellite of the Milky Way. We determine the logarithmic slope of the mass function for substructure beyond the local Universe to be 1.1(+0.6)(-0.4), with an average mass fraction of 3.3(+3.6)(-1.8) per cent, by combining data on both of these recently discovered galaxies. Our results are consistent with the predictions from cold dark matter simulations at the 95 per cent confidence level, and therefore agree with the view that galaxies formed hierarchically in a Universe composed of cold dark matter.
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The role of allergic responses to dietary antigens in the pathogenesis of inflammatory Bowel Disease (IBD) remains speculative. We studied 50 patients with Ulcerative Colitis (UC), 50 patients with Crohn's Disease (CD) and 100 healthy controls (HC) matched for sex and age. In these patients total serum IgE and specific IgE to ten selected foods were estimated using Phadebas PRIST and RAST. There was no significant difference in the total serum IgE level between UC, CD and HC. The percentage of positive reaction to specific IgE was significantly lower in HC (score 1-2: 7%; score 2: 3%) compared with UC (score 1-2: 24%, p less than 0.004; score 2: 8%, n.s.) and CD (score 1-2: 16%, n.s.; score 2: 12%, p less than 0.03). In CD with colic or ileocolic involvement, the percentage of patients with a positive response to RAST was significantly greater (score 1-2: 26%; score 2: 21%) than in CD with ileal involvement. The considerable increase in positive results to RAST in IBD may be due to a greater absorption of antigens through the diseased wall.