Search Publications

First Detection of Sign-reversed Linear Polarization from the Forbidden [O I] 630.03 nm Line

de Wijn, A. G.; Socas-Navarro, H.; Vitas, N.

We report on the detection of linear polarization of the forbidden [O I] 630.03 nm spectral line. The observations were carried out in the broader context of the determination of the solar oxygen abundance, an important problem in astrophysics that still remains unresolved. We obtained spectro-polarimetric data of the forbidden [O I] line at 630.0…

Point and Compact Hα Sources in the Interior of M33

Joner, Michael D.; Roming, Peter W. A.; Hintz, Eric G. +2 more

A variety of interesting objects such as Wolf-Rayet stars, tight OB associations, planetary nebulae, X-ray binaries, etc., can be discovered as point or compact sources in Hα surveys. How these objects distribute through a galaxy sheds light on the galaxy star formation rate and history, mass distribution, and dynamics. The nearby galaxy M33 is an…

A New Orbit for the Eclipsing Binary V577 Oph

Jeffery, Elizabeth J.; Barnes, Thomas G., III; Skillen, Ian +1 more

Pulsating stars in eclipsing binary systems are unique objects for providing constraints on stellar models. To fully leverage the information available from the binary system, full orbital radial velocity curves must be obtained. We report 23 radial velocities for components of the eclipsing binary V577 Oph, whose primary star is a δ Sct variable.…

Debris Disks and the Zodiacal Light Explored by the Akari Mid-Infrared All-Sky Survey

Oyabu, Shinki; Inutsuka, Shu-ichiro; Onaka, Takashi +7 more

Halo Pressure Profile through the Skew Cross-power Spectrum of the Sunyaev-Zel’dovich Effect and CMB Lensing in Planck

Cooray, Asantha; Feng, Chang; Keating, Brian +1 more

We measure the cosmic microwave background (CMB) skewness power spectrum in Planck, using frequency maps of the HFI instrument and the Sunyaev-Zel’dovich (SZ) component map. The two-to-one skewness power spectrum measures the cross-correlation between CMB lensing and the thermal SZ effect. We also directly measure the same cross-correlation using …

The XMM deep survey in the Chandra Deep Field South

Vignali, C.; Gilli, R.; Ranalli, P. +3 more

The Chandra Deep Field South (CDF-S) was observed by XMM-Newton for about 3 Ms in many periods over the past decade (2001-2002 and 2008-2009). The main goal of the survey was to obtain good quality X-ray spectroscopy of the active galactic nuclei responsible for the bulk of the X-ray background. We present the scientific highlights of the XMM-Newt…

Swept Forward Magnetic Field Variability in High-Latitude Regions of Saturn's Magnetosphere

Coates, A. J.; Dougherty, M. K.; Masters, A. +3 more

Swept forward field is the term given to configurations of magnetic field wherein the field lines deviate from the meridional planes of a planet in the direction of its rotation. Evidence is presented for swept-forward field configurations on Cassini orbits around Saturn from the first half of 2008. These orbits were selected on the basis of high …

Radial Variations of Outward and Inward Alfvénic Fluctuations Based on Ulysses Observations

Wu, D. J.; Yang, L.; Shi, J. K. +4 more

Ulysses magnetic and plasma data are used to study hourly scale Alfvénic fluctuations in the solar polar wind. The calculated energy ratio {R}_{vA}²(cal) of inward to outward Alfvén waves is obtained from the observed Walén slope through an analytical expression, and the observed {R}_{vA}^2<…

Dust clouds and plasmoids in Saturn's magnetosphere as seen with four Cassini instruments

Khalisi, Emil

We revisit the evidence for a ;dust cloud; observed by the Cassini spacecraft at Saturn in 2006. The data of four instruments are simultaneously compared to interpret the signatures of a coherent swarm of dust that would have remained near the equatorial plane for as long as six weeks. The conspicuous pattern, as seen in the dust counters of the C…

Down to earth: Popularisation of geo-information services in the Netherlands

Kerstens, Nathalie; Giannopapa, Christina; Dolmans, Sharon +1 more

The popularisation of geo-information services contributes to achieving Europe's 2020 goals to become a "smart, sustainable and inclusive growth economy" [1]. From a utilitarian perspective, this implies making the benefits of geo-information available to the largest number of users possible. To this end earth observation data has been made public…