Search Publications
Propagation Characteristics of Two Coronal Mass Ejections from the Sun Far into Interplanetary Space
Wang, Rui; Liu, Ying D.; Hu, Huidong +1 more
Propagation of coronal mass ejections (CMEs) from the Sun far into interplanetary space is not well understood, due to limited observations. In this study we examine the propagation characteristics of two geo-effective CMEs, which occurred on 2005 May 6 and 13, respectively. Significant heliospheric consequences associated with the two CMEs are ob…
Tethered Prominence-CME Systems Captured during the 2012 November 13 and 2013 November 3 Total Solar Eclipses
Habbal, Shadia R.; Druckmüller, Miloslav; Alzate, Nathalia +1 more
We report on white light observations of high latitude tethered prominences acquired during the total solar eclipses of 2012 November 13 and 2013 November 3, at solar maximum, with a field of view spanning several solar radii. Distinguished by their pinkish hue, characteristic of emission from neutral hydrogen and helium, the four tethered promine…
An Evolving GeV Spectrum from Prompt to Afterglow: The Case of GRB 160509A
Tang, Qing-Wen; Wang, Xiang-Yu; Tam, Pak-Hin Thomas +1 more
We present the high-energy emission properties of GRB 160509A, from its prompt mission to late afterglow phase. GRB 160509A contains two emission episodes: 0-40 s and 280-420 s after the burst onset ({t}0). The relatively high fluence of GRB 160509A allows us to establish an evolving spectrum above 100 MeV. During the first emission epi…
Long-term Spectral Variability of the Ultraluminous X-Ray Source Holmberg IX X-1
Jithesh, V.; Wang, Zhongxiang; Misra, Ranjeev
We investigate the long-term spectral variability in the ultraluminous X-ray source Holmberg IX X-1. By analyzing the data from 8 Suzaku and 13 XMM-Newton observations conducted between 2001 and 2015, we perform a detailed spectral modeling for all spectra with simple models and complex physical models. We find that the spectra can be well explain…
Starburst-driven Superwinds in Quasar Host Galaxies
Haas, Martin; Barthel, Peter; Wilkes, Belinda +1 more
During the past five decades astronomers have been puzzled by the presence of strong absorption features including metal lines, observed in the optical and ultraviolet spectra of quasars, signaling inflowing and outflowing gas winds with relative velocities up to several thousands of km s-1. In particular, the location of these winds—cl…
Observational Signatures of a Kink-unstable Coronal Flux Rope Using Hinode/EIS
Young, P. R.; Régnier, S.; Verwichte, E. +3 more
The signatures of energy release and energy transport for a kink-unstable coronal flux rope are investigated via forward modeling. Synthetic intensity and Doppler maps are generated from a 3D numerical simulation. The CHIANTI database is used to compute intensities for three Hinode/EIS emission lines that cover the thermal range of the loop. The i…
High Dense Gas Fraction in a Gas-rich Star-forming Galaxy at z = 1.2
Carilli, Chris; Daddi, Emanuele; Dannerbauer, Helmut +3 more
We report observations of dense molecular gas in the star-forming galaxy EGS 13004291 (z = 1.197) using the Plateau de Bure Interferometer. We tentatively detect HCN and HNC J=2\to 1 emission when stacked together at 4σ significance, yielding line luminosities of {L}HCN(J=2\to 1)}\prime =(9+/- 3)× {10}9 K km s…
Stability of Sulphur Dimers (S2) in Cometary Ices
Lunine, J. I.; Mousis, O.; Ronnet, T. +5 more
S2 has been observed for decades in comets, including comet 67P/Churyumov-Gerasimenko. Despite the fact that this molecule appears ubiquitous in these bodies, the nature of its source remains unknown. In this study, we assume that S2 is formed by irradiation (photolysis and/or radiolysis) of S-bearing molecules embedded in th…
The Magnetic Future of the Sun
Metcalfe, Travis S.; Judge, Philip G.; Guinan, Edward +2 more
We analyze space- and ground-based data for the old (7.0 ± 0.3 Gyr) solar analogs 16 Cyg A and B. The stars were observed with the Cosmic Origins UV Spectrographs on the Hubble Space Telescope (HST) on 2015 October 23 and 2016 February 3, respectively, and with the Chandra X-ray Observatory on 2016 February 7. Time-series data in Ca II data are us…
The Polarization Signature of Photospheric Magnetic Fields in 3D MHD Simulations and Observations at Disk Center
Rezaei, R.; Puschmann, K. G.; Beck, C. +1 more
Before using three-dimensional (3D) magnetohydrodynamical (MHD) simulations of the solar photosphere in the determination of elemental abundances, one has to ensure that the correct amount of magnetic flux is present in the simulations. The presence of magnetic flux modifies the thermal structure of the solar photosphere, which affects abundance d…