Search Publications
Evidence of deflected super-Alfvénic electron jet in a reconnection region with weak guide field
Xu, Xiaojun; Yuan, Zhigang; Huang, Shiyong +4 more
Recent numerical simulations demonstrated that electron diffusion region develops into two-scale structure, i.e., the inner electron diffusion region and the outer electron diffusion region. The outer diffusion region is manifested as super-Alfvénic electron jet embedded in central current sheet. However, the electron jets are deflected from neutr…
Pre-flare Dynamics of Sunspot Groups
Korsós, M. B.; Ludmány, A.; Baranyi, T.
Several papers provide evidence that the most probable sites of flare onset are the regions of high horizontal magnetic field gradients in solar active regions. Besides the localization of flare-producing areas, this work intends to reveal the characteristic temporal variations in these regions prior to flares. This study uses sunspot data instead…
The Two-dimensional Spatial Distributions of the Globular Clusters and Low-mass X-Ray Binaries of NGC 4649
Zezas, A.; Luo, B.; Fabbiano, G. +5 more
We report significant anisotropies in the projected two-dimensional (2D) spatial distributions of globular clusters (GCs) of the giant Virgo elliptical galaxy NGC 4649 (M60). Similar features are found in the 2D distribution of low-mass X-ray binaries (LMXBs), both associated with GCs and in the stellar field. Deviations from azimuthal symmetry su…
Testing rate-dependent corrections on timing mode EPIC-pn spectra of the accreting neutron star GX 13+1
Sanna, A.; Guainazzi, M.; Robba, N. R. +6 more
When the EPIC-pn instrument on board XMM-Newton is operated in Timing mode, high count rates (>100 counts s-1) of bright sources may affect the calibration of the energy scale, resulting in a modification of the real spectral shape. The corrections related to this effect are then strongly important in the study of the spectral proper…
On the Kinematic Separation of Field and Cluster Stars across the Bulge Globular NGC 6528
Prada Moroni, P. G.; Milone, A. P.; Lagioia, E. P. +12 more
We present deep and precise multi-band photometry of the Galactic bulge globular cluster NGC 6528. The current data set includes optical and near-infrared images collected with ACS/WFC, WFC3/UVIS, and WFC3/IR on board the Hubble Space Telescope. The images cover a time interval of almost 10 yr, and we have been able to carry out a proper-motion se…
CH in absorption in IRAS 16293-2422
Ceccarelli, C.; Caux, E.; Vastel, C. +3 more
While recent studies of the solar-mass protostar IRAS 16293-2422 have focused on its inner arcsecond, the wealth of Herschel/Heterodyne Instrument for the Far-Infrared (HIFI) data has shown that the structure of the outer envelope and of the transition region to the more diffuse interstellar medium is not clearly constrained. We use rotational gro…
The problematically short superwind of OH/IR stars. Probing the outflow with the 69 µm spectral band of forsterite
Waters, L. B. F. M.; Blommaert, J. A. D. L.; Min, M. +4 more
Aims: Spectra of OH/IR stars show prominent spectral bands of crystalline olivine (Mg(2 - 2x)Fe(2x)SiO4). To learn more about the timescale of the outflows of OH/IR stars, we study the spectral band of crystalline olivine at 69 µm.
Methods: The 69 µm band is of interest because its width and p…
Herschel observations of gamma-ray burst host galaxies: implications for the topology of the dusty interstellar medium
Palazzi, E.; Greiner, J.; Hunt, L. K. +11 more
Long-duration gamma-ray bursts (GRBs) are indisputably related to star formation, and their vast luminosity in gamma rays pin-points regions of star formation independent of galaxy mass, out to the epoch of re-ionisation. As such, GRBs provide a unique tool for studying star forming galaxies out to high-z independent of luminosity. Most of our und…
How Robust are the Size Measurements of High-redshift Compact Galaxies?
Ho, Luis C.; Huang, Song; Peng, Chien Y. +1 more
Massive quiescent galaxies at z ≈ 2 are apparently much more compact than galaxies of comparable mass today. How robust are these size measurements? We perform comprehensive simulations to determine possible biases and uncertainties in fitting single-component light distributions to real galaxies. In particular, we examine the robustness of the me…
Dusty Disks around Central Stars of Planetary Nebulae
Rauch, Thomas; De Marco, Orsola; Chu, You-Hua +4 more
Only a few percent of cool, old white dwarfs (WDs) have infrared excesses interpreted as originating in small hot disks due to the infall and destruction of single asteroids that come within the star's Roche limit. Infrared excesses at 24 µm were also found to derive from the immediate vicinity of younger, hot WDs, most of which are still ce…