Search Publications
The structure of the planetary nebula NGC 2371 in the visible and mid-infrared
Ramos-Larios, Gerardo; Phillips, J. P.
We investigate the structure of the planetary nebula NGC 2371 using [O III] λ5007 imaging taken with the Jacobus Kapteyn 1.0 m telescope, and [N II] λ6584, [O III] λ5007 and Hα results acquired with the Hubble Space Telescope. These are supplemented with archival mid-infrared (MIR) observations taken with the Spitzer Space Telescope. We note the p…
A 20 GHz bright sample for δ > +72° - I. Catalogue
Prandoni, I.; Ricci, R.; López-Caniego, M. +9 more
During 2010-11, the Medicina 32-m dish hosted the seven-feed 18-26.5 GHz receiver built for the Sardinia Radio Telescope, with the goal to perform its commissioning. This opportunity was exploited to carry out a pilot survey at 20 GHz over the area for δ > +72°.3. This paper describes all the phases of the observations, as they were performed u…
A two-fluid model of the bifurcated current sheet
Yoon, Peter H.; Janaki, M. S.; Dasgupta, Brahmananda
Recent satellite observations show that current sheets in the space plasma environment are often characterized by bifurcated structures. The majority of the available models of the bifurcated current sheet in the literature are based upon equilibrium Vlasov-Maxwell kinetic theory. While in principle, kinetic models are more fundamental, investigat…
Magnetic-topology evolution in NOAA AR 10501 on 2003 November 18
Somov, B. V.; Oreshina, A. V.; Oreshina, I. V.
Context. NOAA AR 10501 produced three flares on 2003 November 18. Two of them were associated with coronal mass ejections (CMEs).
Aims: We model the magnetic-field structure of the active region, study the magnetic-topology evolution, and propose a scenario of the observed events.
Methods: The coronal magnetic field is reconstructed usin…
High Ionization Species in the Nearby Interstellar Medium from an Exhaustive Analysis of the IUE INES Database
Freire Ferrero, R.; Morales Durán, C.; Halbwachs, J. -L. +1 more
Main-sequence (MS) and giant late-B and early-A type stars are the best targets for searching for nearby interstellar (IS) Si IV and C IV resonance lines because they are not able to produce them, either in atmospheric layers or in their circumstellar environment, and because many stars of these spectral types are nearby and located in the local i…
Optical polarization of quasars and the Balmer edge feature revealed by ultraviolet and polarized visible to near-infrared emissions
Hu, Renyu; Zhang, Shuang-Nan
Polarized emission from a quasar is produced by wavelength-independent electron scattering that surrounds its accretion disc. Thus, contamination from the host galaxy is avoided and the intrinsic emission spectrum of its accretion disc is revealed. Ultraviolet (UV) emission from a quasar is normally free of contamination from its host galaxy. Ther…
Erratum: Herschel/SPIRE observations of the TWA brown dwarf disc 2MASSW J1207334-393254★
Lodato, G.; Riaz, B.; Stamatellos, D. +1 more
We have revised our analysis of the SPIRE observations of 2MASSW J1207334-393254 (2M1207). Recent PACS observations show a bright source located ∼25 arcsec east of 2M1207. There are issues in terms of the detection/non-detection of the bright source when comparing the Spitzer, WISE and PACS observations. The object's detection/non-detection is app…
Discovery of the spectroscopic binary nature of the Cepheids X Puppis and XX Sagittarii
Szabados, László; Kiss, Csaba; Derekas, Aliz +1 more
We present the analysis of photometric and spectroscopic data of two bright Galactic Cepheids, X Puppis and XX Sagittarii. Based on the available data in the literature as well as our own observations spanning 75 years, we conclude that both Cepheids belong to spectroscopic binary systems. However, the data are not sufficient to determine the orbi…
Aerial electromagnetic sounding of the lithosphere of Venus
Harrison, Keith P.; Barr, Amy C.; Grimm, Robert E. +4 more
Electromagnetic (EM) investigation depths are larger on Venus than Earth due to the dearth of water in rocks, in spite of higher temperatures. Whistlers detected by Venus Express proved that lightning is present, so the Schumann resonances ∼10-40 Hz may provide a global source of electromagnetic energy that penetrates ∼10-100 km. Electrical conduc…
Equatorially confined warm trapped ions at around 100 eV near the plasmapause
Yamauchi, M.; Dandouras, I.; Rème, H. +1 more
Near the equatorial plasmapause at around 4-5 Earth radius (RE) geocentric distance, pancake distributed tens of eV ions are sometimes found, as previously reported by Olsen et al. (1987). Cluster CIS data during perigee traversals in 2001-2002 (nearly 200 traversals) revealed new features of these equatorially-trapped warm ions. (1) Th…