Search Publications
The nongravitational interactions of dark matter in colliding galaxy clusters
Massey, Richard; Harvey, David; Tittley, Eric +2 more
Collisions between galaxy clusters provide a test of the nongravitational forces acting on dark matter. Dark matter’s lack of deceleration in the “bullet cluster” collision constrained its self-interaction cross section σDM/m < 1.25 square centimeters per gram (cm2/g) [68% confidence limit (CL)] (σDM, self-inter…
On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko
Bertaux, Jean-Loup; Da Deppo, Vania; Naletto, Giampiero +63 more
Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen c…
Multiple images of a highly magnified supernova formed by an early-type cluster galaxy lens
Fontana, Adriano; Weiner, Benjamin J.; Schmidt, Kasper B. +28 more
In 1964, Refsdal hypothesized that a supernova whose light traversed multiple paths around a strong gravitational lens could be used to measure the rate of cosmic expansion. We report the discovery of such a system. In Hubble Space Telescope imaging, we have found four images of a single supernova forming an Einstein cross configuration around a r…
Evidence for mature bulges and an inside-out quenching phase 3 billion years after the Big Bang
Wuyts, S.; Förster Schreiber, N. M.; Genzel, R. +14 more
Most present-day galaxies with stellar masses ≥1011 solar masses show no ongoing star formation and are dense spheroids. Ten billion years ago, similarly massive galaxies were typically forming stars at rates of hundreds solar masses per year. It is debated how star formation ceased, on which time scales, and how this “quenching” relate…
Dust measurements in the coma of comet 67P/Churyumov-Gerasimenko inbound to the Sun
Accolla, Mario; Altobelli, Nicolas; Bertaux, Jean-Loup +78 more
Critical measurements for understanding accretion and the dust/gas ratio in the solar nebula, where planets were forming 4.5 billion years ago, are being obtained by the GIADA (Grain Impact Analyser and Dust Accumulator) experiment on the European Space Agency’s Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko. Between 3.6 and 3.4 astro…
67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio
Wurz, P.; Bochsler, P.; Altwegg, K. +29 more
The provenance of water and organic compounds on Earth and other terrestrial planets has been discussed for a long time without reaching a consensus. One of the best means to distinguish between different scenarios is by determining the deuterium-to-hydrogen (D/H) ratios in the reservoirs for comets and Earth’s oceans. Here, we report the direct i…
The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta
Langevin, Y.; Bellucci, G.; Jaumann, R. +75 more
The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared…
Organic compounds on comet 67P/Churyumov-Gerasimenko revealed by COSAC mass spectrometry
Krüger, Harald; McKenna-Lawlor, Susan; Gautier, Thomas +18 more
Comets harbor the most pristine material in our solar system in the form of ice, dust, silicates, and refractory organic material with some interstellar heritage. The evolved gas analyzer Cometary Sampling and Composition (COSAC) experiment aboard Rosetta’s Philae lander was designed for in situ analysis of organic molecules on comet 67P/Churyumov…
Black hole feedback in the luminous quasar PDS 456
Harrison, F. A.; Stern, D.; Behar, E. +17 more
The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spheri…
Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature
Wurz, P.; Bochsler, P.; Altwegg, K. +29 more
Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system,…