Search Publications
Scientific innovations from the Mars aerosol optical depth based on satellite data with a temporal resolution of hours
Gebhardt, Claus; Abuelgasim, Abdelgadir
The ExoMars Trace Gas Orbiter (TGO), Emirates Mars Mission (EMM), and possible future Mars stationary satellite(s) will provide innovative data products on the optical depth of dust and water ice clouds in the Martian atmosphere with a temporal resolution of hours. The science phase of TGO has begun in April 2018, and the EMM science operation is …
Identification of Herbig Ae/Be Stars in the Small Magellanic Cloud
Zijlstra, A. A.; Simon, Joshua D.; Oliveira, Joana M. +12 more
Protoplanetary disks orbiting intermediate-mass stars, Herbig Ae/Be stars, that have formed in a metal-poor environment may evolve differently than their Galactic cousins. A study of the planet-formation process in such an environment requires identification and characterization of a sample of candidates. We have observed several stars in the Smal…
Multiple Scattering Effects in the Interplanetary Medium: Evaluation Using SOHO SWAN and MAVEN EUVM Lyman α Measurements
Quémerais, Eric; Schmidt, Walter; Thiemann, Edward +2 more
Interplanetary background measurements can be used to derive the solar flux that is illuminating the atoms in the interplanetary medium. We present a new algorithm combining measurements from the Solar Wind ANisotropies (SWAN)-Solar Heliospheric Observatory (SOHO) Lyman α photometer with Earth-based solar flux measurements to derive the solar illu…
Comparative analysis of solar radio bursts before and during CME propagation
Poedts, S.; Dididze, G.; Shergelashvili, B. M. +5 more
Context. As is well known, coronal mass ejection (CME) propagation often results in the fragmentation of the solar atmosphere on smaller regions of density (magnetic field) enhancement (depletion). It is expected that this type of fragmentation may have radio signatures.
Aims: The general aim of the present paper is to perform a comparative a…
Infrared imaging of high-mass young stellar objects: evidence of multiple shocks and of a new protostar/star eclipsing system
Tapia, Mauricio; Persi, Paolo
We present deep near- and mid-infrared images of six high-mass young stellar objects (YSOs) in order to help understand the physical mechanisms of their formation. We have searched for shocked H2 emission around such massive protostars. All but one of these regions exhibit series of molecular hydrogen emission knots, either in perfect a…
A Method to Estimate the Physical Properties of Magnetospheric Generators From Observations of Quiet Discrete Auroral Arcs
Gunell, H.; De Keyser, J.; Lamy, H. +3 more
We discuss a method to estimate the properties of a magnetospheric generator using a quasi-electrostatic magnetosphere-ionosphere coupling model and in situ or remote sensing observations of discrete quiet arcs. We first construct an ensemble of Vlasov equilibrium solutions for generator structures formed at magnetospheric plasma interfaces. For e…
HD 126516: A Triple System Containing a Short-period Eclipsing Binary
Henry, Gregory W.; Fekel, Francis C.; Sowell, James R.
From numerous radial velocities as well as Johnson B and V differential photoelectric photometry, we have determined the orbital elements and other properties of the single-lined triple system HD 126516. This system consists of a narrow-lined F5 V star and an unseen M dwarf companion in a 2.1241 day circular orbit. The small, low-mass secondary pr…
Localized Structures and Turbulent Spectra in the Magnetopause
Sharma, R. P.; Pathak, Neha; Uma, R.
Kinetic Alfvén wave (KAW) and whistler wave play a key role in the framework of turbulence and reconnection. There are lot of observations of these wave in the magnetopause region. The present paper deals with the nonlinear evolution of KAW and a weak whistler wave through the preexisting magnetic reconnection site. For this study the dynamical ev…
AT 2017fvz: a nova in the dwarf irregular galaxy NGC 6822
Zheng, W.; Filippenko, A. V.; Henze, M. +7 more
A transient in the Local Group dwarf irregular galaxy NGC 6822 (Barnard's Galaxy) was discovered on 2017 August 2 and is only the second classical nova discovered in that galaxy. We conducted optical, near-ultraviolet, and X-ray follow-up observations of the eruption, the results of which we present here. This `very fast' nova had a peak V-band ma…
Ionization state of the accretion disc in the neutron star low-mass X-ray binary 4U 1728-34
Méndez, Mariano; Xiang, Fu-Yuan; Lyu, Ming +1 more
We analysed an XMM-Newton plus a simultaneous Rossi X-ray Timing Explorer observation and a separate Suzaku observation of the neutron star low-mass X-ray binary 4U 1728-34. We fitted the X-ray spectra with the self-consistent reflection model RELXILL. We found that the inclination angle of 4U 1728-34 is 49 ± 5 degree, consistent with the upper li…