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Estimates of Emission-Region Locations of Fermi Flat-Spectrum Radio Quasars
Zhang, Li; Yan, Dahai; Zeng, Houdun
We have studied the location of emission regions through modeling the quasi-simultaneous multifrequency spectral energy distributions of 21 Fermi flat-spectrum radio quasars (FSRQs) in the frame of a multicomponent one-zone leptonic model. In our calculations, we took the detailed broad line region (BLR) structure into account, and discussed the e…
New Evidence Supporting Cluster Membership for the Keystone Calibrator Delta Cephei
Gieren, W.; Turner, D.; Majaess, D.
New and existing UBVJHKs , spectroscopic, NOMAD, Hubble Space Telescope, and revised Hipparcos observations are employed to determine properties for δ Cep and its host star cluster. The multi-faceted approach ensured that uncertainties were mitigated (σ/d ~ 2%). The following fundamental parameters were inferred for δ Cep: E(B - V) = 0.…
Observations of Ionospheric Electron Beams in the Plasma Sheet
Parks, G. K.; Fu, S. Y.; Pu, Z. Y. +3 more
Electrons streaming along the magnetic field direction are frequently observed in the plasma sheet of Earth’s geomagnetic tail. The impact of these field-aligned electrons on the dynamics of the geomagnetic tail is however not well understood. Here we report the first detection of field-aligned electrons with fluxes increasing at ∼1keV forming a “…
Antitruncated stellar light profiles in the outer regions of STAGES spiral galaxies: bulge or disc related?
Wolf, Christian; Aragón-Salamanca, Alfonso; Hoyos, Carlos +2 more
We present a comparison of azimuthally averaged radial surface brightness µ(r) profiles and analytical bulge-disc decompositions (de Vaucouleurs, r1/4 bulge plus exponential disc) for spiral galaxies using Hubble Space Telescope/Advanced Camera for Surveys V-band imaging from the Space Telescope A901/2 Galaxy Evolution Survey (STA…
Revealing the sub-structures of the magnetic reconnection separatrix via particle-in-cell simulation
Deng, X. H.; Huang, S. Y.; Yuan, Z. G. +7 more
Magnetic separatrix is an important boundary layer separating the inflow and outflow regions in magnetic reconnection. In this article, we investigate the sub-structures of the separatrix region by using two-and-half dimensional electromagnetic particle-in-cell simulation. The separatrix region can be divided into two sub-regions in terms of the i…
Understanding shock dynamics in the inner heliosphere with modeling and Type II radio data: The 2010-04-03 event
St. Cyr, O. C.; Odstrcil, D.; Gopalswamy, N. +3 more
The 2010 April 03 solar event was studied using observations from STEREO SECCHI, SOHO LASCO, and Wind kilometric Type II data (kmTII) combined with WSA-Cone-ENLIL model simulations performed at the Community Coordinated Modeling Center (CCMC). In particular, we identified the origin of the coronal mass ejection (CME) using STEREO EUVI and SOHO EIT…
On the prospective detection of polyoxymethylene in comet 67P/Churyumov-Gerasimenko with the COSIMA instrument onboard Rosetta
Briois, Christelle; Cottin, Hervé; Fray, Nicolas +5 more
The presence of polyoxymethylene (POM) in cometary grains has been debated years ago. Although never proven, its presence can not be excluded. Rosetta, the ESA mission to comet 67P/Churyumov-Gerasimenko, may answer this question. On board the spacecraft, COSIMA (COmetary Secondary Ion Mass Analyzer) will analyze the grains ejected from the nucleus…
The continuum intensity as a function of magnetic field. II. Local magnetic flux and convective flows
Solanki, S. K.; Borrero, J. M.; Kobel, P.
Context. To deepen our understanding of the role of small-scale magnetic fields in active regions (ARs) and in the quiet Sun (QS) on the solar irradiance, it is fundamental to investigate the physical processes underlying their continuum brightness. Previous results showed that magnetic elements in the QS reach larger continuum intensities than in…
Dynamics of long-period ULF waves in the plasma sheet: Coordinated space and ground observations
Zhang, T. L.; Nakamura, R.; Baumjohann, W. +11 more
Spacecraft and ground-based observations are used to study characteristics of ultralow frequency waves in the plasma sheet from the postmidnight to morning local time sectors in the terrestrial magnetosphere. Field line resonance (FLR) type oscillations with discrete and latitude-dependent frequencies in the ranges of 1.7-2.0 and 3.0-3.2 mHz are o…
Auto-consistent metallicity and star formation history of the nearest blue compact dwarf galaxy NGC 6789
Pérez-Montero, E.; García-Benito, R.
We present a detailed auto-consistent study of the nearest blue compact dwarf galaxy NGC 6789 by means of optical and ultraviolet (UV) archive photometry data and optical long-slit Intermediate dispersion Spectrograph and Imaging System-William Herschel Telescope (WHT) spectroscopy observations of the five brightest star-forming knots. The analysi…