Search Publications
Localized sources of water vapour on the dwarf planet (1)Ceres
Marston, Anthony; Müller, Thomas; Lee, Seungwon +10 more
The `snowline' conventionally divides Solar System objects into dry bodies, ranging out to the main asteroid belt, and icy bodies beyond the belt. Models suggest that some of the icy bodies may have migrated into the asteroid belt. Recent observations indicate the presence of water ice on the surface of some asteroids, with sublimation a potential…
H2D+ observations give an age of at least one million years for a cloud core forming Sun-like stars
Caselli, Paola; Menten, Karl M.; Sipilä, Olli +8 more
The age of dense interstellar cloud cores, where stars and planets form, is a crucial parameter in star formation and difficult to measure. Some models predict rapid collapse, whereas others predict timescales of more than one million years (ref. 3). One possible approach to determining the age is through chemical changes as cloud contraction occu…
A massive galaxy in its core formation phase three billion years after the Big Bang
Kirkpatrick, Allison; Franx, Marijn; van Dokkum, Pieter +13 more
Most massive galaxies are thought to have formed their dense stellar cores in early cosmic epochs. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes, but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we report a candidate core in the…
The rarity of dust in metal-poor galaxies
Sandstrom, Karin M.; Bolatto, Alberto D.; Leroy, Adam K. +7 more
Galaxies observed at redshift z>6, when the Universe was less than a billion years old, thus far very rarely show evidence of the cold dust that accompanies star formation in the local Universe, where the dust-to-gas mass ratio is around one per cent. A prototypical example is the galaxy Himiko (z = 6.6), which--a mere 840million years after th…
Inefficient star formation in extremely metal poor galaxies
Wang, Junzhi; Gao, Yu; Zhang, Zhi-Yu +5 more
The first galaxies contain stars born out of gas with few or no `metals' (that is, elements heavier than helium). The lack of metals is expected to inhibit efficient gas cooling and star formation, but this effect has yet to be observed in galaxies with an oxygen abundance (relative to hydrogen) below a tenth of that of the Sun. Extremely metal po…
Two γ-ray bursts from dusty regions with little molecular gas
Kohno, K.; Nakanishi, K.; Tamura, Y. +4 more
Long-duration γ-ray bursts are associated with the explosions of massive stars and are accordingly expected to reside in star-forming regions with molecular gas (the fuel for star formation). Previous searches for carbon monoxide (CO), a tracer of molecular gas, in burst host galaxies did not detect any emission. Molecules have been detected as ab…