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Development of an ensemble Kalman filter data assimilation system for the Venusian atmosphere
Sugimoto, Norihiko; Takagi, Masahiro; Kouyama, Toru +3 more
The size and mass of Venus is similar to those of the Earth; however, its atmospheric dynamics are considerably different and they are poorly understood due to limited observations and computational difficulties. Here, we developed a data assimilation system based on the local ensemble transform Kalman filter (LETKF) for a Venusian Atmospheric GCM…
Discovery of Galactic O iv and O v X-ray absorption due to transition temperature gas in the PKS 2155-304 spectrum
Kaastra, J.; Bonamente, M.; Paerels, F. +4 more
Far-ultraviolet (FUV) observations have revealed transition temperature gas (TTG; log T(K) 5), located in the lower Galactic halo and in high-velocity clouds. However, the corresponding X-ray absorption has so far remained mostly undetected. In order to make an improvement in this respect in Galactic X-ray absorption studies, we accumulated very d…
New observational limits on dark radiation in braneworld cosmology
Mathews, Grant J.; Kusakabe, Motohiko; Gangopadhyay, Mayukh Raj +1 more
A dark radiation term arises as a correction to the energy-momentum tensor in the simplest five-dimensional RS-II brane-world cosmology. In this paper we revisit the constraints on dark radiation based upon the newest results for light element nuclear reaction rates, observed light element abundances, and the power spectrum of the cosmic microwave…
Physical properties of seven binary and higher-order multiple OB systems
Mayer, Pavel; Harmanec, Petr; Chini, Rolf +7 more
Analyses of multi-epoch, high-resolution (R 50 000) optical spectra of seven early-type systems provided various important new insights with respect to their multiplicity. First determinations of orbital periods were made for HD 92206 C (2.^d022), HD 112244 (27.^d665), HD 164438 (10.^d25), HD 123056 A ( 1314 d) and HD 123056 B (<2 d); the orbit…
Wavelet reconstruction of E and B modes for CMB polarization and cosmic shear analyses
Leistedt, Boris; Peiris, Hiranya V.; McEwen, Jason D. +1 more
We present new methods for mapping the curl-free (E-mode) and divergence-free (B-mode) components of spin 2 signals using spin directional wavelets. Our methods are equally applicable to measurements of the polarization of the cosmic microwave background (CMB) and the shear of galaxy shapes due to weak gravitational lensing. We derive pseudo- and …
High signal-to-noise spectral characterization of the planetary-mass object HD 106906 b
Fortney, Jonathan J.; Meyer, Michael R.; Quanz, Sascha P. +4 more
Context. Directly imaged planets are ideal candidates for spectroscopic characterization of their atmospheres. The angular separations that are typically close to their host stars, however, reduce the achievable contrast and thus signal-to-noise ratios (S/N).
Aims: We spectroscopically characterize the atmosphere of HD 106906 b, which is a yo…
Gas inflows towards the nucleus of the Seyfert 2 galaxy NGC 1667
Schnorr-Müller, Allan; Storchi-Bergmann, Thaisa; Nagar, Neil M. +1 more
We use optical spectra from the inner 2 × 3 kpc2 of the Seyfert 2 galaxy NGC 1667, obtained with the Gemini Multi-Object Spectrograph integral field spectrograph on the Gemini South telescope at a spatial resolution of ≈240 pc, to assess the feeding and feedback processes in this nearby active galactic nucleus (AGN). We have identified …
X-ray orbital modulation of a white dwarf accreting from an L dwarf. The system SDSS J121209.31+013627.7
de Martino, D.; Stelzer, B.; Wynn, G. A. +2 more
In an XMM-Newton observation of the binary SDSS J121209.31+013627.7, consisting of a white dwarf and an L dwarf, we detect X-ray orbital modulation as proof of accretion from the substellar companion onto the magnetic white dwarf. We constrain the system geometry (inclination as well as magnetic and pole-cap angle) through modelling of the X-ray l…
"TNOs are Cool": A survey of the trans-Neptunian region. XIII. Statistical analysis of multiple trans-Neptunian objects observed with Herschel Space Observatory
Lellouch, E.; Stansberry, J.; Doressoundiram, A. +3 more
Context. Gravitationally bound multiple systems provide an opportunity to estimate the mean bulk density of the objects, whereas this characteristic is not available for single objects. Being a primitive population of the outer solar system, binary and multiple trans-Neptunian objects (TNOs) provide unique information about bulk density and intern…
The stellar mass-size relation for cluster galaxies at z = 1 with high angular resolution from the Gemini/GeMS multiconjugate adaptive optics system
Glazebrook, Karl; Abraham, Roberto; Bayliss, Matthew +7 more
We present the stellar mass-size relation for 49 galaxies within the z = 1.067 cluster SPT-CL J0546-5345, with full width at half-maximum ∼80-120 mas Ks-band data from the Gemini multiconjugate adaptive optics system (GeMS/GSAOI). This is the first such measurement in a cluster environment, performed at sub-kpc resolution at rest-frame …