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Circumnuclear Rings and Lindblad Resonances in Spiral Galaxies
Díaz, R. J.; Agüero, M. P.; Gaspar, G. +5 more
In order to study the location of circumnuclear rings (CNR) and their possible relation with the inner Lindblad resonances (ILR), we investigate a sample of spiral galaxies. For this purpose, we have obtained and analyzed medium resolution spectra of five spiral galaxies in the range 6200-6900 Å. Through the Hα emission line, we constructed the ra…
On Geometrical Invariants of the Magnetic Field Gradient Tensor in Turbulent Space Plasmas: Scale Variability in the Inertial Range
Marcucci, Maria Federica; Consolini, Giuseppe; Materassi, Massimo +1 more
In a recent paper, Consolini et al. investigated the statistics of geometrical invariants of the coarse-grained gradient tensor of plasma velocity for a case study of space plasma turbulence. They showed how, at spatial scales near the proton inertial length, there is evidence for the occurrence of dissipation structures along the Vieillefosse’s t…
Detailed X-ray spectroscopy of the magnetar 1E 2259+586
Tiengo, A.; Israel, G.; Mereghetti, S. +7 more
Magnetic field geometry is expected to play a fundamental role in magnetar activity. The discovery of a phase-variable absorption feature in the X-ray spectrum of SGR 0418+5729, interpreted as cyclotron resonant scattering, suggests the presence of very strong non-dipolar components in the magnetic fields of magnetars. We performed a deep XMM-Newt…
Kinetic Analysis of the Energy Transport of Two-Flow Components in the Plasma Sheet
Cao, Jin-Bin; Ren, Ganming; Ma, Yuduan
Satellite observations indicate that multiple components often exist in the plasma sheet, particularly during impulsive fast flow events. In this paper, we perform a kinetic analysis of the energy transport of plasma sheet ion flow using a model of two-component plasma sheet ion flows (Background convection flow represented by subscript "b" and Fa…
New powerful outburst of the unusual young star V1318 Cygni S (LkHα 225)
Magakian, T. Yu.; Movsessian, T. A.; Andreasyan, H. R. +1 more
Aims: Young double star V1318 Cyg, which is associated with a small isolated star-forming region around HAeBe star BD+40°4124, has very unusual photometric and spectral behavior. We present results of photometric and spectroscopic observations in the optical range.
Methods: We carried out BVRI CCD photometric observations of V1318 Cyg fr…
The multi-outburst activity of the magnetar in Westerlund I
Campana, S.; Tiengo, A.; Götz, D. +17 more
After two major outbursts in 2006 and 2011, on 2017 May 16 the magnetar CXOU J164710.2-455216, hosted within the massive star cluster Westerlund I, emitted a short (∼20 ms) burst, which marked the onset of a new active phase. We started a long-term monitoring campaign with Swift (45 observations), Chandra (five observations), and NuSTAR (four obse…
On the diagnostic power of FIR/sub-mm SED fitting in massive galactic molecular clumps
Pitts, Rebecca L.; Barnes, Peter J.; Varosi, Frank
We used far-infrared (FIR) and sub-millimetre continuum data from Herschel and the Atacama Pathfinder EXperiment (APEX) to fit pixel-by-pixel modified Planck spectral energy distributions to prestellar and protostellar clumps in the Census of High- and Medium-mass Protostars (CHaMP) (280° < ℓ < 300°, -4° < b < +2°). We present maps of …
Field-Aligned Structures of the Poloidal-Mode ULF Wave Electric Field: Phase Relationship Implications
Zong, Q. G.; Ren, Jie; Zhou, X. Z. +2 more
Spacecraft observations within recent decades have demonstrated that ultralow frequency (ULF) waves play an important role in the dynamics of Earth's magnetosphere through drift and/or drift-bounce resonance with different particle species. The phase relationship between resonant particles and waves can help us understand the wave-particle interac…
Swift X-ray and UV observations of SDSS J141118.31+481257.6 during its first ever recorded superoutburst
Maccarone, T. J.; Rivera Sandoval, L. E.
SDSS J141118.31+481257.6 is an ultracompact white dwarf binary (or AM CVn system) with an orbital period of 46 min. We analyse ∼23 ks of X-ray and ultraviolet (UV) data taken with the Neil Gehrels Swift Observatory during its first ever recorded outbursts. The events took place 13 yr after the system was discovered. We detected three events in our…
Asymmetric Distribution of Weak Photospheric Magnetic Field Values
Mursula, Kalevi; Virtanen, Ilpo; Getachew, Tibebu
We use the synoptic maps of the photospheric magnetic field observed at Wilcox Solar Observatory, Mount Wilson Observatory, Kitt Peak, SOHO/MDI, SOLIS/VSM, and SDO/HMI to study the distribution of weak photospheric magnetic field values in 1974-2018. We fit the histogram distribution of weak field values for each synoptic map of the six data sets …