Search Publications
Statistical analysis of electron lifetimes at GEO: Comparisons with chorus-driven losses
Balikhin, M. A.; Mourenas, D.; Boynton, R. J.
The population of electrons in the Earth's outer radiation belt increases when the magnetosphere is exposed to high-speed streams of solar wind, coronal mass ejections, magnetic clouds, or other disturbances. After this increase, the number of electrons decays back to approximately the initial population. This study statistically analyzes the life…
Modulated inflation models and primordial black holes
Erfani, Encieh
For the first time, the running of the running of the spectral index βs has been measured by Planck. This parameter is crucial for dark matter primordial black holes (PBHs) formation. We study the PBHs formation in inflation potentials with superimposed periodic oscillations. We show that the value of βs suggested by the rece…
The physical conditions in IRDC clumps from Herschel/HIFI observations of H2O
Shipman, R. F.; van der Tak, F. F. S.; Wyrowski, F. +2 more
Context. The earliest phases of high-mass star formation are poorly understood.
Aims: Our goal is to determine the physical conditions and kinematic structure of massive starforming cloud clumps.
Methods: We analyse H2O 557 GHz line profiles observed with HIFI toward four positions in two infrared-dark cloud clumps. By compari…
Herschel SPIRE FTS relative spectral response calibration
Valtchanov, Ivan; Hopwood, Rosalind; Lu, Nanyao +9 more
Herschel/SPIRE Fourier transform spectrometer (FTS) observations contain emission from both the Herschel Telescope and the SPIRE Instrument itself, both of which are typically orders of magnitude greater than the emission from the astronomical source, and must be removed in order to recover the source spectrum. The effects of the Herschel Telescop…
The X-Ray Zurich Environmental Study (X-ZENS). I. Chandra and XMM-Newton Observations of Active Galactic Nuclei in Galaxies in nearby Groups
Finoguenov, A.; Silverman, J. D.; Carollo, C. M. +4 more
We describe X-ray observations with Chandra and XMM-Newton of 18 M group ~ 1-6 × 1013 M ⊙, z ~ 0.05 galaxy groups from the Zurich ENvironmental Study. The X-ray data aim at establishing the frequency and properties, unaffected by host galaxy dilution and obscuration, of active galactic nuclei (AGNs) in central and …
Penumbral-like Filaments in the Solar Photosphere as a Manifestation of Flux Emergence
Guglielmino, Salvo L.; Romano, Paolo; Zuccarello, Francesca
Rare observations of the solar photosphere show the appearance of orphan penumbrae, filamentary structures very similar to a bundle of sunspot penumbral filaments not connected to any umbra. Lim et al. found an orphan penumbra in active region NOAA 11391 near a mature sunspot. We analyze a different data set to study the same structure using the S…
Cepheids and RR Lyrae stars in the K2 fields
Plachy, E.; Molnar, L.; Szabo, R.
With the step-and-stare approach of the K2 mission, Kepler will be able to observe a large number of Cepheid an RR Lyrae stars. In this paper we summarize the target selection efforts, the scientific goals that can be achieved by Kepler, and the first impressions based on the K2 two-wheel engineering test data.
A multi-wavelength survey of AGN in massive clusters: AGN distribution and host galaxy properties
Sarajedini, Vicki L.; Klesman, Alison J.
We investigate the effect of environment on the presence and fuelling of active galactic nuclei (AGN) by identifying galaxies hosting AGN in massive galaxy clusters and the fields around them. We have identified AGN candidates via optical variability (178), X-ray emission (74), and mid-IR SEDs (64) in multi-wavelength surveys covering regions cent…
X-rays from wind-blown bubbles: an XMM-Newton detection of NGC 2359
Zhekov, Svetozar A.
We present an analysis of the XMM-Newton observation of the wind-blown bubble NGC 2359. This is the first detection of this object in X-rays. The X-ray emission of NGC 2359 is soft and originates from a thermal plasma with a typical temperature of kT ∼ 0.2 keV. A direct comparison between the one-dimensional hydrodynamic model of wind-blown bubble…
Tracking Back the Solar Wind to Its Photospheric Footpoints from Wind Observations - A Statistical Study
Li, Gang; Deng, Yuanyong; Tan, Baolin +2 more
It is of great importance to track the solar wind back to its photospheric source region and identify the related current sheets; this will provide key information for investigating the origin and predictions of the solar wind. We report a statistical study relating the photospheric footpoint motion and in-situ observation of current sheets in the…