Search Publications
Prospects for Asteroseismology of Rapidly Rotating B-Type Stars
Saio, Hideyuki
In rapidly rotating stars, Coriolis forces and centrifugal deformations modify the properties of oscillations; the Coriolis force is important for low-frequency modes, while the centrifugal deformation affects mainly p-modes. Here, we discuss properties of g- and r-mode oscillations in rotating stars. Predicted frequency spectra of high-order g-mo…
Temperature dependence of ultraviolet line parameters in network and internetwork regions of the quiet Sun and coronal holes
Peter, H.; Curdt, W.; Wang, X. +3 more
Aims: We study the temperature dependence of the average Doppler shift and the non-thermal line width in network and internetwork regions for both the quiet Sun (QS) and the coronal hole (CH), by using observations of the Solar Ultraviolet Measurements of Emitted Radiation instrument onboard the Solar and Heliospheric Observatory spacecraft. …
HMT production and sublimation during thermal process of cometary organic analogs. Implications for its detection with the ROSETTA instruments
Cottin, Hervé; Fray, Nicolas; Benilan, Yves +3 more
One important component of refractory organic residues synthesized from interstellar/cometary ice analogues is hexamethylenetetramine (HMT, C6H12N4). However, HMT has never been observed in any astrophysical or planetary environment so far. We investigated thermal evolution of HMT above ambient temperature. The syn…
Comparison of Force-free Coronal Magnetic Field Modeling Using Vector Fields from Hinode and Solar Dynamics Observatory
Wiegelmann, T.; Thalmann, J. K.; Tiwari, S. K.
Photospheric magnetic vector maps from two different instruments are used to model the nonlinear force-free coronal magnetic field above an active region. We use vector maps inferred from polarization measurements of the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (HMI) and the Solar Optical Telescope's Spectropolarimeter (SP) on b…
Far-ultraviolet and far-infrared bivariate luminosity function of galaxies: Complex relation between stellar and dust emission
Buat, Véronique; Burgarella, Denis; Takeuchi, Tsutomu T. +2 more
Far-ultraviolet (FUV) and far-infrared (FIR) luminosity functions (LFs) of galaxies show a strong evolution from z = 0 to z = 1, but the FIR LF evolves much stronger than the FUV one. The FUV is dominantly radiated from newly-formed short-lived OB stars, while the FIR is emitted by dust grains heated by the FUV radiation field. It is known that du…
Collimation and Scattering of the Active Galactic Nucleus Emission in the Sombrero Galaxy
Ricci, T. V.; Steiner, J. E.; Menezes, R. B.
We present an analysis of a data cube of the central region of M104, the Sombrero galaxy, obtained with the GMOS-IFU of the Gemini-South telescope, and report the discovery of collimation and scattering of the active galactic nucleus (AGN) emission in the circumnuclear region of this galaxy. Analysis with PCA Tomography and spectral synthesis reve…
On the Hubble Space Telescope Trigonometric Parallax of the Dwarf Nova SS Cygni
Nelan, Edmund P.; Bond, Howard E.
SS Cygni is one of the brightest dwarf novae (DNe), and one of the best studied prototypes of the cataclysmic variables. Astrometric observations with the Fine Guidance Sensors (FGSs) on the Hubble Space Telescope (HST), published in 2004, gave an absolute trigonometric parallax of 6.06 ± 0.44 mas. However, recent very long baseline interferometry…
The preferentially magnified active nucleus in IRAS F10214+4724 - III. VLBI observations of the radio core
McKean, J. P.; Heywood, I.; Jarvis, M. J. +5 more
We report 1.7 GHz very long baseline interferometry (VLBI) observations of IRAS F10214+4724, a lensed z = 2.3 obscured quasar with prodigious star formation. We detect what we argue to be the obscured active nucleus with an effective angular resolution of <50 pc at z = 2.3. The S1.7 = 210 µJy (9σ) detection of this unresolved s…
A minor merger scenario for the ultraluminous X-ray source ESO 243-49 HLX-1 - II. Constraints from photometry
Soria, R.; Zampieri, L.; Mapelli, M. +1 more
The point-like X-ray source HLX-1, close to the S0 galaxy ESO 243-49, is the brightest known ultraluminous X-ray source and one the strongest intermediate-mass black hole candidates. We argue that the counterpart of HLX-1 may be the nucleus of a satellite galaxy, undergoing minor merger with the S0 galaxy. We investigate this scenario by running a…
Scattering properties of Saturn's rings in the far ultraviolet from Cassini UVIS spectra
Colwell, Joshua E.; Esposito, Larry W.; Bradley, E. Todd
We use Cassini UVIS data to determine the scattering properties of Saturn's ring particles in the FUV. We have replaced the scattering function from the classical Chandrasekhar single scattering radiative transfer equation for reflectance with a ring wake model for the A and B rings derived from stellar occultations. The free parameters in this mo…