Search Publications
Simultaneous FAST and Double Star TC1 observations of broadband electrons during a storm time substorm
Dandouras, I.; Fazakerley, A. N.; Le Contel, O. +13 more
Broadband electrons (BBEs) exhibit remarkable electron flux enhancements over a broad energy range (0.03-30 keV) near the equatorward edge of the auroral oval during geomagnetic storms. Here, we report a BBE event observed by the Fast Auroral Snapshot (FAST) satellite at 1355-1359 UT, ∼61°-66° invariant latitudes, ∼0600 magnetic local time (MLT), …
Multiwavelength Observations of the Runaway Binary HD 15137
Gies, Douglas R.; Roettenbacher, Rachael M.; De Becker, Michaël +6 more
HD 15137 is an intriguing runaway O-type binary system that offers a rare opportunity to explore the mechanism by which it was ejected from the open cluster of its birth. Here, we present recent blue optical spectra of HD 15137 and derive a new orbital solution for the spectroscopic binary and physical parameters of the O star primary. We also pre…
Evidence for a Strong End-On Bar in the Ringed σ-Drop Galaxy NGC 6503
Nelson, T.; Chomiuk, L.; Freeland, E. +1 more
We use WIYN High-resolution Infrared Camera H-band (1.6 µm) imaging, archival Spitzer, Hubble Space Telescope, and Galaxy Evolution Explorer data simulations, and data from the literature to argue for the presence of a strong end-on bar in nearby spiral galaxy NGC 6503. The evidence consists of both photometric and kinematic signatures as we…
Time-Resolved Spectral Variability of the Prompt Emission from GRB 070125 Observed with Suzaku/WAM
Gandhi, Poshak; Yamaoka, Kazutaka; Fukazawa, Yasushi +12 more
Time-resolved spectral analyses of GRB 070125 with significant photon detections over the MeV regime using Suzaku/WAM data are reported. The prompt emission interval was divided into 10 time regions, and their spectra were reproduced by a Band function or a cutoff power-law model. The spectra show a complex evolution; a soft-hard-soft trend is see…
Magnetic Field Structures in a Facular Region Observed by THEMIS and Hinode
Bommier, V.; Schmieder, B.; Guo, Y. +1 more
The main objective of this paper is to build and compare vector magnetic maps obtained by two spectral polarimeters, i.e. THEMIS/MTR and Hinode SOT/SP, using two inversion codes (UNNOFIT and MELANIE) based on the Milne - Eddington solar atmosphere model. To this end, we used observations of a facular region within active region NOAA 10996 on 23 Ma…
Fitting of dust spectra with genetic algorithms. I. Perspectives and limitations
Lebzelter, T.; Kerschbaum, F.; Baier, A.
Aims: We present an automatised fitting procedure for the IR range of AGB star spectra. Furthermore we explore the possibilities and boundaries of this method.
Methods: We combine the radiative transfer code DUSTY with the genetic algorithm PIKAIA in order to improve an existing spectral fit significantly.
Results: In order to test …
The Recent Star Formation History of NGC 5102
Freeman, Kenneth C.; Norman, Colin A.; Hidalgo, Sebastian L. +2 more
We present Hubble Space Telescope photometry of young stars in NGC 5102, a nearby gas-rich post-starburst S0 galaxy with a bright young stellar nucleus. We use the IAC-pop/MinnIAC algorithm to derive the recent star formation history in three fields in the bulge and disk of NGC 5102. In the disk fields, the recent star formation rate has declined …
Characteristics of storm time electric fields in the inner magnetosphere derived from Cluster data
Farrugia, C. J.; Khotyaintsev, Yu. V.; Torbert, R. B. +6 more
Storm-time electric fields in the inner magnetosphere measured by Cluster are reported in this study. First, we show two events around the time when Dst index is at a minimum. The electric field possibly related to subauroral ion drifts and/or undershielding is measured inside the inner edge of the electron plasma sheet in the eveningside. For the…
Reconstructing CME Structures from IPS Observations Using a Phenomenological Model
Tappin, S. J.; Howard, T. A.
We present an extension of the Tappin - Howard (TH) phenomenological model (Tappin and Howard, Space Sci. Rev.147, 55, 2009) for coronal mass ejection reconstruction to use interplanetary scintillation g-map data. The necessary changes to the model are discussed. We then use the modified model to reconstruct two major interplanetary disturbances o…
Investigating the Complex X-Ray Spectrum of a Broad-Line 2MASS Red Quasar: XMM-Newton Observation of FTM 0830+3759
Nicastro, Fabrizio; Fiore, Fabrizio; Bianchi, Stefano +3 more
We report results from a 50 ks XMM-Newton observation of the dust-reddened broad-line quasar FTM 0830+3759 (z = 0.413) selected from the Faint Images of the Radio Sky at Twenty cm/Two Micron All Sky Survey red quasar survey. For this active galactic nucleus (AGN), a very short 9 ks Chandra exposure had suggested a feature-rich X-ray spectrum and H…