Netherlands Institute for Space Research

About: Netherlands Institute for Space Research is a facility organization based out in Utrecht, Netherlands. It is known for research contribution in the topics: Galaxy & Neutron star. The organization has 737 authors who have published 3026 publications receiving 106632 citations. The organization is also known as: SRON & Space Research Organisation Netherlands.

The ASTRO-H X-ray astronomy satellite

Abstract: The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of ΔE ≤ 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts.

A large increase in U.S. methane emissions over the past decade inferred from satellite data and surface observations

Abstract: The global burden of atmospheric methane has been increasing over the past decade, but the causes are not well understood. National inventory estimates from the U.S. Environmental Protection Agency indicate no significant trend in U.S. anthropogenic methane emissions from 2002 to present. Here we use satellite retrievals and surface observations of atmospheric methane to suggest that U.S. methane emissions have increased by more than 30% over the 2002–2014 period. The trend is largest in the central part of the country, but we cannot readily attribute it to any specific source type. This large increase in U.S. methane emissions could account for 30–60% of the global growth of atmospheric methane seen in the past decade.

Spitzer mid-infrared spectroscopy of ICES toward extincted background stars

Abstract: A powerful way to directly observe the solid-state inventory of dense molecular clouds is by infrared spectroscopy of background stars. We present Spitzer IRS 5-20 μm spectra of ices toward stars behind the Serpens and Taurus molecular clouds, probing visual extinctions of 10-34 mag. These data provide the first complete inventory of solid-state material in dense clouds before star formation begins. The spectra show prominent 6.0 and 6.85 μm bands. In contrast to some young stellar objects (YSOs), most (~75%) of the 6.0 μm band is explained by the bending mode of pure H2O ice. In realistic mixtures this number increases to 85%, because the peak strength of the H2O bending mode is very sensitive to the molecular environment. The strength of the 6.85 μm band is comparable to what is observed toward YSOs. Thus, the production of the carrier of this band does not depend on the energetic input of a nearby source. The spectra show large abundances of CO and CO2 (20%-40% with respect to H2O ice). Compared with YSOs, the band profile of the 15 μm CO2 bending mode lacks the signatures of crystallization, confirming the cold, pristine nature of these lines of sight. After the dominant species are removed, there are residuals that suggest the presence of minor species such as HCOOH and possibly NH3. Clearly, models of star formation should begin with dust models already coated with a fairly complex mixture of ices.

The complex circumstellar environment of HD 142527

Abstract: Context. The recent findings of gas giant planets around young A-type stars suggest that disks surrounding Herbig Ae/Be stars will develop planetary systems. An interesting case is HD 142527, for which previous observations revealed a complex circumstellar environment and an unusually high ratio of infrared to stellar luminosity. Its properties differ considerably from other Herbig Ae/Be stars. This suggests that the disk surrounding HD 142527 is in an uncommon evolutionary stage. Aims. We aim for a better understanding of the geometry and evolutionary status of the circumstellar material around the Herbig Ae/Be star HD 142527. Methods. We map the composition and spatial distribution of the dust around HD 142527. We analyze SEST and ATCA millimeter data, VISIR N and Q-band imaging and spectroscopy. We gather additional relevant data from the literature. We use the radiative transfer code MCMax to construct a model of the geometry and density structure of the circumstellar matter, which fits all of the observables satisfactorily. Results. We find that the disk of HD 142527 has three geometrically distinct components separated by a disk gap running from 30 to 130 AU. There is a geometrically flat inner disk running from 0.3 AU up to 30 AU; an optically thin halo-like component of dust in the inner disk regions; and a massive self-shadowed outer disk running from 130 AU up to 200 AU. We derived a total dust mass in