Search Publications
Magnetotail magnetic flux monitoring based on simultaneous solar wind and magnetotail observations
Gordeev, E. I.; Sergeev, V. A.; Milan, S. E. +3 more
The magnetotail magnetic flux (MTF) is an important global variable to describe the magnetospheric state and dynamics. Existing methods of MTF estimation on the basis of the polar cap area, inferred from observations of global auroras and field-aligned currents, do not allow benchmarking due to the absence of a gauge for comparison; besides, they …
Optical spectroscopy of the microquasar GRS 1758-258: a possible intermediate mass system?
Luque-Escamilla, Pedro L.; Martí, Josep; Muñoz-Arjonilla, Álvaro J.
Context. GRS 1758-258 is one of two prototypical microquasars towards the Galactic center direction discovered almost a quarter of a century ago. The system remains poorly studied in the optical domain due to its counterpart being a very faint and absorbed target in a crowded region of the sky.
Aims: Our aim is to investigate GRS 1758-258 in …
The ionized X-ray outflowing torus in ESO 323-G77: low-ionization clumps confined by homogeneous warm absorbers
Miniutti, G.; Krongold, Y.; Longinotti, A. L. +2 more
We report on the long- and short-term X-ray spectral analysis of the polar-scattered Seyfert 1.2 galaxy ESO 323-G77, observed in three epochs between 2006 and 2013 with Chandra and XMM-Newton. Four high-resolution Chandra observations give us a unique opportunity to study the properties of the absorbers in detail, as well as their short time-scale…
Obscured AGNs in Bulgeless Hosts discovered by WISE: The Case Study of SDSS J1224+5555
Hickox, R. C.; Secrest, N. J.; Satyapal, S. +6 more
There is mounting evidence that supermassive black holes (SMBHs) form and grow in bulgeless galaxies. However, a robust determination of the fraction of active galactic nuclei (AGNs) in bulgeless galaxies, an important constraint to models of SMBH seed formation and merger-free models of AGN fueling, is unknown, since optical studies have been sho…
On the properties of dust and gas in the environs of V838 Monocerotis
Decin, L.; Swinyard, B. M.; De Beck, E. +4 more
Aims: We aim to probe the close and distant circumstellar environments of the stellar outburst object V838 Mon.
Methods: Herschel far-infrared imaging and spectroscopy were taken at several epochs to probe the central point source and the extended environment of V838 Mon. PACS and SPIRE maps were used to obtain photometry of the dust imm…
Structure and kinematics of the clouds surrounding the Galactic mini-starburst W43 MM1
Braine, J.; van der Tak, F.; Wyrowski, F. +2 more
Massive stars have a major influence on their environment, yet their formation is difficult to study as they form quickly in highly obscured regions and are rare, hence more distant than lower mass stars. Westerhout 43 (W43) is a highly luminous galactic massive star-forming region at a distance of 5.5 kpc and the MM1 part hosts a particularly mas…
Improved SOT (Hinode mission) high resolution solar imaging observations: 2—Photometric properties of sunspot umbral dots
Koutchmy, S.; Adjabshirizadeh, A.; Goodarzi, H.
The origin and evolution of solar sunspots in deep photospheric layers are not yet well understood. The case of a quasi-symmetric single mature sunspot near the solar centre is selected for analysis. We use the best available observations of the partial Sun free of turbulent Earth atmospheric effects from the Solar Optical Telescope (SOT) onboard …
A possible mechanism for the formation of magnetic field dropouts in the coma of 67P/Churyumov-Gerasimenko
Altwegg, K.; Huang, Z.; Jia, X. +10 more
The Rosetta Plasma Consortium MAGnetometer (RPC-MAG) has detected signatures of diamagnetic regions associated with comet 67P/Churyumov-Gerasimenko at distances from 30 to 400 km at different heliocentric distances, which is larger than what has been predicted by numerical simulations of the cometary plasam environment. The physical mechanism behi…
Spectral components in black hole X-ray binaries
Malzac, J.
This paper summarises our current understanding of the spectral continuum components observed in black hole X-ray binaries. The consequences for theoretical models are discussed with an emphasis on the constraints set by observations on the nature of the X-ray corona in different spectral states.
The CONSERT operations planning process for the Rosetta mission
Altobelli, Nicolas; Vallat, Claire; Hubault, Armelle +28 more
The COmet Nucleus Sounding Experiment by Radio wave Transmission (CONSERT / Rosetta) has been designed to sound the interior of the comet 67P/Churyumov-Gerasimenko. This instrument consists of two parts: one onboard Rosetta and the other one onboard Philae. A good CONSERT science measurement sequence requires joint operations of both spacecrafts i…