Search Publications
Detection of Plasma Fluctuations in White-light Images of the Outer Solar Corona: Investigation of the Spatial and Temporal Evolution
Romano, P.; Antonucci, E.; Spadaro, D. +2 more
This work focuses on the first results from the identification and characterization of periodic plasma density fluctuations in the outer corona, observed in STEREO-A COR1 white-light image time series. A two-dimensional reconstruction of the spatial distribution and temporal evolution of the coronal fluctuation power has been performed over the wh…
X-ray source population study of the starburst galaxy M 83 with XMM-Newton
Pietsch, W.; Haberl, F.; Ducci, L. +1 more
Aims: We present the results obtained from the analysis of three XMM-Newton observations of M 83. The aims of the paper are studying the X-ray source populations in M 83 and calculating the X-ray luminosity functions of X-ray binaries for different regions of the galaxy.
Methods: We detected 189 sources in the XMM-Newton field of view in…
Does a Scaling Law Exist between Solar Energetic Particle Events and Solar Flares?
Kahler, S. W.
Among many other natural processes, the size distributions of solar X-ray flares and solar energetic particle (SEP) events are scale-invariant power laws. The measured distributions of SEP events prove to be distinctly flatter, i.e., have smaller power-law slopes, than those of the flares. This has led to speculation that the two distributions are…
Chemical abundances in Orion protoplanetary discs: integral field spectroscopy and photoevaporation models of HST 10
Tsamis, Y. G.; Walsh, J. R.; Henney, W. J. +2 more
Photoevaporating protoplanetary discs (proplyds) in the vicinity of hot massive stars, such as those found in Orion, are important objects of study for the fields of star formation, early disc evolution, planetary formation and H II region astrophysics. Their element abundances are largely unknown, unlike those of the main-sequence stars or the ho…
Analogs of solid nanoparticles as precursors of aromatic hydrocarbons
Mutschke, H.; Jäger, C.; Gadallah, K. A. K.
Context. Aromatic =CH and C=C vibrational bands have been observed within shocked interstellar regions, indicating the presence of aromatic emission carriers such as PAHs, which may have been created from adjacent molecular cloud material by interaction with a shock front.
Aims: We investigate the evolution of the aromatic =CH and C=C vibrati…
Using THEMIS data to resolve the discrepancy between CRISM/OMEGA and TES modeled phyllosilicate abundance in Mawrth Vallis
Moersch, Jeffrey E.; Viviano, Christina E.
We explore the effects of spatial resolution on the detectability of phyllosilicates in the thermal infrared dataset from the Mars Global Surveyor Thermal Emission Spectrometer (TES). Data from the Mars Odyssey THermal Emission Imaging System (THEMIS) instrument is used to resolve spatial resolution driven discrepancies between detection of phyllo…
Rapid Evolution of the Solar Atmosphere during the Impulsive Phase of a Microflare Observed with the Extreme-ultraviolet Imaging Spectrometer aboard Hinode: Hints of Chromospheric Magnetic Reconnection
Brosius, Jeffrey W.
We obtained rapid cadence (11.2 s) EUV stare spectra of a solar microflare with the Extreme-ultraviolet Imaging Spectrometer aboard Hinode. The intensities of lines formed at temperatures too cool to be found in the corona brightened by factors around 16 early during this event, indicating that we observed a site of energy deposition in the chromo…
Observations of interstellar helium pickup ions in the inner heliosphere
Gloeckler, George; Zurbuchen, Thomas H.; Fisk, Lennard A. +5 more
During the MESSENGER spacecraft's interplanetary trajectory to Mercury, the Fast Imaging Plasma Spectrometer (FIPS) measured the first helium pickup ion distributions at a heliocentric distance (R) ranging between 0.3 and 0.7 AU. From several transits of MESSENGER through the interstellar helium gravitational focusing cone, we map the cone structu…
X-Ray Transients in the Advanced LIGO/Virgo Horizon
Kanner, Jonah; Baker, John; Blackburn, Lindy +4 more
Advanced LIGO and Advanced Virgo will be all-sky monitors for merging compact objects within a few hundred megaparsecs. Finding the electromagnetic counterparts to these events will require an understanding of the transient sky at low redshift (z < 0.1). We performed a systematic search for extragalactic, low redshift, transient events in the X…
Characterization of a Sample of Intermediate-type AGNs. I. Spectroscopic Properties and Serendipitous Discovery of New Dual AGNs
Méndez-Abreu, Jairo; Benítez, Erika; Cruz-González, Irene +6 more
A sample of 10 nearby intermediate-type active galactic nuclei (AGNs) drawn from the Sloan Digital Sky Survey is presented. The aim of this work is to provide estimations of the black hole (BH) mass for the sample galaxies from the dynamics of the broad-line region. For this purpose, a detailed spectroscopic analysis of the objects was done. Using…