Search Publications
The Acceleration of Energetic Particles at Coronal Shocks and Emergence of a Double Power-law Feature in Particle Energy Spectra
Chen, Yao; Giacalone, Joe; Guo, Fan +1 more
We present numerical modeling of particle acceleration at coronal shocks propagating through a streamer-like magnetic field by solving the Parker transport equation with spatial diffusion both along and across the magnetic field. We show that the location on the shock where the high-energy particle intensity is the largest, depends on the energy o…
Signs of accretion in the white dwarf + brown dwarf binary NLTT5306
Maxted, P. F. L.; Page, K. L.; Wynn, G. A. +4 more
We present new XSHOOTER spectra of NLTT5306, a 0.44 ± 0.04 M⊙ white dwarf in a short period (101 min) binary system with a brown dwarf companion that is likely to have previously undergone common envelope evolution. We have confirmed the presence of H α emission and discovered Na I absorption associated with the white dwarf. These obser…
Compact Star-forming Galaxies as Old Starbursts Becoming Quiescent
Ivison, R. J.; Gómez-Guijarro, C.; Magdis, G. E. +8 more
Optically compact star-forming galaxies (SFGs) have been proposed as immediate progenitors of quiescent galaxies, although their origin and nature are debated. Were they formed in slow secular processes or in rapid merger-driven starbursts? Answering this question would provide fundamental insight into how quenching occurs. We explore the location…
The integrated properties of the CALIFA galaxies: model-derived galaxy parameters and quenching of star formation
Zezas, A.; Ciesla, L.; Charmandaris, V. +6 more
We present a study of the integrated properties of the 835 galaxies in the Calar-Alto Legacy Integral Field spectroscopy Area survey. To derive the main physical parameters of the galaxies we have fitted their UV-to-IR spectral energy distributions (SEDs) with sets of theoretical models using CIGALE. We perform a comparison of the integrated galax…
Local standard of rest based on Gaia DR2 catalog
Zhu, Zi; Liu, Jia-Cheng; Ding, Ping-Jie
The local standard of rest (LSR) provides a reference framework for studies of Galactic kinematics. Determination of the LSR corresponds to the measurement of solar peculiar motion, which is under debate due to the fact that different methods and samples have been used. Adopting the astrometric data and line-of-sight velocities of main sequence st…
Relativistic Components of the Ultra-fast Outflow in the Quasar PDS 456 from Chandra/HETGS, NuSTAR, and XMM-Newton Observations
Danehkar, Ashkbiz; Nowak, Michael A.; Marshall, Herman L. +1 more
We present the spectral analysis of Chandra/High Energy Transmission Grating Spectrometer (HETGS) and NuSTAR observations of the quasar PDS 456 from 2015, and XMM-Newton and NuSTAR archival data from 2013 to 2014, together with Chandra/HETGS data from 2003. We analyzed these three different epochs in a consistent way, looking for absorption featur…
Search for Surviving Companions of Progenitors of Young LMC SN Ia Remnants
Leibundgut, Bruno; Pan, Kuo-Chuan; Ricker, Paul M. +9 more
We have used two methods to search for surviving companions of Type Ia supernova progenitors in three Balmer-dominated supernova remnants in the Large Magellanic Cloud: 0519-69.0, 0505-67.9 (DEM L71), and 0548-70.4. In the first method, we use the Hubble Space Telescope photometric measurements of stars to construct color-magnitude diagrams (CMDs)…
H/C elemental ratio of the refractory organic matter in cometary particles of 67P/Churyumov-Gerasimenko
Alexander, C.; Hilchenbach, M.; Engrand, C. +11 more
Context. Because comets are part of the most primitive bodies of our solar system, establishing their chemical composition and comparing them to other astrophysical bodies gives new constraints on the formation and evolution of organic matter throughout the solar system. For two years, the time-of-flight secondary ion mass spectrometer COmetary Se…
Comprehensive Analysis of the Formation of a Shock Wave Associated with a Coronal Mass Ejection
Susino, Roberto; Frassati, Federica; Mancuso, Salvatore +1 more
On 2014 November 1, a solar prominence eruption associated with a C2.7 class flare and a type II radio burst resulted in a fast partial halo coronal mass ejection (CME). Images acquired in the extreme ultraviolet (EUV) by the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) and PROBA2/SWAP and in white light (WL) by Solar and Heliosph…
An observer's view on the future of asteroseismology
Paparó, Margit
Scientific research is a continuous process, and the speed of future progress can be estimated by the pace of finding explanations for previous research questions. In this observer's based view of stellar pulsation and asteroseismology, we start with the earliest observations of variable stars and the techniques used to observe them. The earliest …