Search Publications
Cometary plasma response to interplanetary corotating interaction regions during 2016 June-September: a quantitative study by the Rosetta Plasma Consortium
Henri, Pierre; Simon Wedlund, Cyril; Nilsson, Hans +14 more
Four interplanetary corotating interaction regions (CIRs) were identified during 2016 June-September by the Rosetta Plasma Consortium (RPC) monitoring in situ the plasma environment of the comet 67P/Churyumov-Gerasimenko (67P) at heliocentric distances of ∼3-3.8 au. The CIRs, formed in the interface region between low- and high-speed solar wind st…
Optical Identifications of High-Redshift Galaxy Clusters from the Planck Sunyaev-Zeldovich Survey
Aghanim, N.; Bikmaev, I. F.; Khamitov, I. M. +8 more
We present the results of optical identifications and spectroscopic redshift measurements for galaxy clusters from the second Planck catalogue of Sunyaev-Zeldovich sources (PSZ2) located at high redshifts, z ≈ 0.7-0.9. We used the data of optical observations with the Russian-Turkish 1.5-mtelescope (RTT-150), the Sayan Observatory 1.6-m telescope,…
The NuSTAR Extragalactic Surveys: Source Catalog and the Compton-thick Fraction in the UDS Field
Harrison, F. A.; Stern, D.; Alexander, D. M. +19 more
We present the results and the source catalog of the NuSTAR survey in the UKIDSS Ultra Deep Survey (UDS) field, bridging the gap in depth and area between NuSTAR’s ECDFS and COSMOS surveys. The survey covers a ∼0.6 deg2 area of the field for a total observing time of ∼1.75 Ms, to a half-area depth of ∼155 ks corrected for vignetting at …
Mass-invariance of the iron enrichment in the hot haloes of massive ellipticals, groups, and clusters of galaxies
Urdampilleta, I.; Simionescu, A.; Kaastra, J. S. +7 more
X-ray measurements find systematically lower Fe abundances in the X-ray emitting haloes pervading groups (kT ≲ 1.7 keV) than in clusters of galaxies. These results have been difficult to reconcile with theoretical predictions. However, models using incomplete atomic data or the assumption of isothermal plasmas may have biased the best-fitting Fe a…
First cosmological constraints combining Planck with the recent gravitational-wave standard siren measurement of the Hubble constant
Di Valentino, Eleonora; Melchiorri, Alessandro
The recent observations of gravitational-wave and electromagnetic emission produced by the merger of the binary neutron-star system GW170817 have opened the possibility of using standard sirens to constrain the value of the Hubble constant. While the reported bound of H0=7 0-8+12 at 68% C.L. is significantly weaker…
Cometary ion dynamics observed in the close vicinity of comet 67P/Churyumov-Gerasimenko during the intermediate activity period
Behar, E.; Nilsson, H.; Goetz, C. +4 more
Aims: Cometary ions are constantly produced in the coma, and once produced they are accelerated and eventually escape the coma. We describe and interpret the dynamics of the cometary ion flow, of an intermediate active comet, very close to the nucleus and in the terminator plane.
Methods: We analysed in situ ion and magnetic field measur…
Laboratory simulations of the Vis-NIR spectra of comet 67P using sub-µm sized cosmochemical analogues
Kappel, D.; Bockelée-Morvan, D.; Capaccioni, F. +16 more
Laboratory spectral measurements of relevant analogue materials were performed in the framework of the Rosetta mission in order to explain the surface spectral properties of comet 67P. Fine powders of coal, iron sulphides, silicates and their mixtures were prepared and their spectra measured in the Vis-IR range. These spectra are compared to a ref…
Olivine-bearing lithologies on the Moon: Constraints on origins and transport mechanisms from M3 spectroscopy, radiative transfer modeling, and GRAIL crustal thickness
Corley, Laura M.; McGovern, Patrick J.; Kramer, Georgiana Y. +8 more
High-resolution hyperspectral data from Chandrayaan-1's Moon Mineralogy Mapper (M3) allow detection of olivine on the lunar surface. Olivine exposed at the surface may originate as mantle material or igneous products (intrusive or extrusive). Potential transport mechanisms include excavation of the mantle or lower crustal material by im…
Discovery of an Ultraviolet Counterpart to an Ultrafast X-Ray Outflow in the Quasar PG 1211+143
Kriss, Gerard A.; Lee, Julia C.; Danehkar, Ashkbiz +5 more
We observed the quasar PG 1211+143 using the Cosmic Origins Spectrograph on the Hubble Space Telescope in 2015 April as part of a joint campaign with the Chandra X-ray Observatory and the Jansky Very Large Array. Our ultraviolet spectra cover the wavelength range 912-2100 Å. We find a broad absorption feature (∼ 1080 {km} {{{s}}}-1) at …
Integrated-light analyses vs. colour-magnitude diagrams. II. Leo A: an extremely young dwarf in the Local Group
Monelli, M.; Gallart, C.; Bernard, E. J. +7 more
Context. Most of our knowledge of the stellar component of galaxies is based on the analysis of distant systems and comes from integrated light data. It is important to test whether the results of the star formation histories (SFH) obtained with standard full-spectrum fitting methods are in agreement with those obtained through colour-magnitude di…