Search Publications
Dawn-dusk asymmetry in solar wind ion entry and dayside precipitation: Results from large-scale simulations
Berchem, J.; Wing, S.; Pitout, F. +2 more
We present the results of numerical studies of the interaction of solar wind ions with the dayside magnetospheric boundary for a southward interplanetary magnetic field and two solar wind speeds (250 and 500 km/s) using the results of global magnetohydrodynamics simulations in conjunction with large-scale kinetic calculations. Results of these stu…
The Origin of the X-Ray Emission from the High-velocity Cloud MS30.7-81.4-118
Henley, David B.; Shelton, Robin L.; Kwak, Kyujin
A soft X-ray enhancement has recently been reported toward the high-velocity cloud MS30.7-81.4-118 (MS30.7), a constituent of the Magellanic Stream. In order to investigate the origin of this enhancement, we have analyzed two overlapping XMM-Newton observations of this cloud. We find that the X-ray enhancement is ~6' or ~100 pc across, and is conc…
Rosette globulettes and shells in the infrared
Gahm, G. F.; Haikala, L. K.; Mäkelä, M. M.
Context. Giant galactic H ii regions surrounding central young clusters show compressed molecular shells, which have broken up into clumps, filaments, and elephant trunks interacting with UV light from central OB stars. Tiny, dense clumps of subsolar mass, called globulettes, form in this environment.
Aims: We observe and explore the nature a…
A search for eclipsing binaries that host discs
Mamajek, Eric E.; Quillen, Alice C.; Bell, Cameron P. M. +3 more
We search for systems hosting eclipsing discs using a complete sample of eclipsing binaries (EBs); those previously identified in the third phase of the Optical Gravitational Lensing Experiment (OGLE-III). Within a subsample of 2823 high-cadence, high-photometric precision and large eclipsing depth detached EBs previously identified in the Large M…
Deconvolving X-Ray Spectral Variability Components in the Seyfert 1.5 NGC 3227
Arévalo, P.; Markowitz, A.
We present the variability analysis of a 100 ks XMM-Newton observation of the Seyfert 1.5 active galaxy, NGC 3227. The observation found NGC 3227 in a period where its hard power-law component displayed remarkably little long-term variability. This lucky event allows us to clearly observe a soft spectral component undergoing a large-amplitude but …
The Resolved Outflow from 3C 48
Shih, Hsin-Yi; Stockton, Alan
We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporti…
Active moon: evidences from Chandrayaan-1 and the proposed Indian missions
Srivastava, Neeraj; Bhandari, Narendra
Chandrayaan-1, the polar Lunar orbiter mission of Indian Space Research Organization, successfully carried out study of Moon's environment and surface processes for a period of about nine months during 2008–2009. The results obtained by the mission established (i) A tenuous but active hydrosphere (ii) Volcanically active and geologically dynamic M…
Scattered Lyman-α radiation of comet 2012/S1 (ISON) observed by SUMER/SOHO
Solanki, S. K.; Vincent, J. -B.; Curdt, W. +3 more
During its sungrazing perihelion passage, comet ISON appeared in the field of view of the SUMER spectrometer and allowed unique observations at far-ultraviolet wavelengths with high spatial and temporal resolution. We report results of these observations completed on November 28, 2013, when the comet was only 2.82 Rʘ away from the Sun. …
Secondary CMB anisotropies from bulk motions in the presence of stochastic magnetic fields
Kunze, Kerstin E.
Bulk motions of electrons along the line of sight induce secondary temperature fluctuations in the postdecoupling, reionized Universe. In the presence of a magnetic field not only the scalar mode but also the vector mode act as a source for the bulk motion. The resulting angular power spectrum of temperature anisotropies of the cosmic microwave ba…
The X-ray emission of the high-mass X-ray binary IGR J17200-3116
Campana, S.; Tiengo, A.; Moretti, A. +3 more
The source IGR J17200-3116 was discovered in the hard X-ray band by INTEGRAL. A periodic X-ray modulation at ∼326 s was detected in its Swift light curves by our group (and subsequently confirmed by a Swift campaign). In this paper, we report on the analysis of all the Swift observations, which were collected between 2005 and 2011, and of an ∼20 k…