Search Publications
The spectral energy distribution of the redshift 7.1 quasar ULAS J1120+0641
Hewett, P. C.; Banerji, M.; Warren, S. J. +7 more
We present new observations of the highest-redshift quasar known, ULAS J1120+0641, redshift z = 7.084, obtained in the optical, at near-, mid-, and far-infrared wavelengths, and in the sub-mm. We combine these results with published X-ray and radio observations to create the multiwavelength spectral energy distribution (SED), with the goals of mea…
A new mechanism for OH vibrational relaxation leading to enhanced CO2 emissions in the nocturnal mesosphere
Sharma, Ramesh D.; Wintersteiner, Peter P.; Kalogerakis, Konstantinos S.
On the basis of experimental and theoretical studies, this paper proposes a new mechanism that contributes to nocturnal 4.3 µm CO2 emissions. It suggests that collisions of ground state O atoms with highly vibrationally excited OH(v), produced by the reaction of H with O3, remove a substantial fraction of the OH(v) vibrationa…
Hydrogen halides measurements in the Venus mesosphere retrieved from SOIR on board Venus express
Vandaele, A. C.; Robert, S.; Wilquet, V. +5 more
The SOIR instrument on board Venus Express regularly sounds the Venus mesosphere using the solar occultation technique. Densities and volume mixing ratios of HCl and HF are measured in the 70-115 km and 75-110 km altitude region respectively, at the Venus terminator. All latitudes from pole to pole are covered. In this work, we study the latitude …
Catalog of Astronomical Positions of Saturn's Moons Obtained by Photographic Observations at the Mao Nasu in 1961-1991
Andruk, V. M.; Pakuliak, L. K.; Yizhakevych, O. M.
In the framework of UkrVO national project the new methods of plate digital image processing are developed. The photographic material of the UkrVO Joint Digital Archive (JDA, http://194.44.35.19/vo-mao/DB/ archivespecial.php) is used for the solution of classic astrometric problem - positional and photometric determinations of objects registered o…
Bias in C IV-based quasar black hole mass scaling relationships from reverberation mapped samples
Shang, Zhaohui; Brotherton, Michael S.; DiPompeo, M. A. +1 more
The masses of the black holes powering quasars represent a fundamental parameter of active galaxies. Estimates of quasar black hole masses using single-epoch spectra are quite uncertain, and require quantitative improvement. We recently identified a correction for C IV λ1549-based scaling relationships used to estimate quasar black hole masses tha…
Technique for diagnosing the flapping motion of magnetotail current sheets based on single-point magnetic field analysis
Barabash, S.; Futaana, Y.; Wei, Y. +5 more
The magnetotail current sheet is active and often flaps back and forth. Knowledge about the flapping motion of current sheet is essential to explore the related magnetotail dynamic processes, e.g., plasma instabilities. Due to the inability of single-point measurements to separate the spatial-temporal variation of magnetic field, the moving veloci…
A statistical study on the whistler waves behind dipolarization fronts
Yuan, Zhigang; Yu, Xiongdong; Huang, Shiyong +5 more
We present a statistical study of whistler waves behind dipolarization fronts (DFs) based on the Cluster satellites measurements during the years 2001-2007. We find 732 DFs during the 7 year tail periods (XGSM ≤ -8 RE and |YGSM| ≤ 10 RE) in the plasma sheet. By constraining the whistler waves in a 1 min …
Optical properties of the Venus upper clouds from the data obtained by Venus Monitoring Camera on-board the Venus Express
Ignatiev, N. I.; Petrova, E. V.; Markiewicz, W. J. +2 more
During more than 6 years of the Venus Express (VEx) mission, the Venus Monitoring Camera (VMC) took around 300 000 images in four channels covering almost all the latitudes, including night and day sides. Here we give an overview of the VMC data and summarize results of retrievals of the optical properties of the Venus upper clouds. The in-flight …
Swift follow-up of IceCube triggers, and implications for the Advanced-LIGO era
Smith, M.; Kowalski, M.; Gehrels, N. +11 more
Between 2011 March and 2014 August Swift responded to 20 triggers from the IceCube neutrino observatory, observing the IceCube 50 per cent confidence error circle in X-rays, typically within 5 h of the trigger. No confirmed counterpart has been detected. We describe the Swift follow-up strategy and data analysis and present the results of the camp…
Decaying dark matter: the case for a deep X-ray observation of Draco
Lovell, Mark R.; Bertone, Gianfranco; Boyarsky, Alexey +2 more
Recent studies of M31, the Galactic Centre (GC), and galaxy clusters have made tentative detections of an X-ray line at ∼3.5 keV that could be produced by decaying dark matter. We use high-resolution simulations of the Aquarius project to predict the likely amplitude of the X-ray decay flux observed in the GC relative to that observed in M31, and …