Search Publications
The AT20G view of Swift/BAT selected AGN: high-frequency radio waves meet hard X-rays
Ghirlanda, G.; Ajello, M.; Murphy, T. +3 more
We cross-matched the 6-year Swift/Burst Alert Telescope (BAT) survey of active galactic nuclei (AGN) with the AT20G radio survey of the southern sky, which is one of the largest high-frequency radio surveys available. With these data we investigated the possible correlation between the radio and the X-ray emission at the highest radio and X-ray fr…
Magnitude and size evolution of bulgeless galaxies
Sachdeva, Sonali
We examine the magnitude and size evolution of bulgeless (discs with no-bulge or pseudo-bulge) galaxies up to z ∼ 0.9 in rest-frame B band. Their evolution is compared to that of normal-discs (or discs with classical bulge). The study is done for luminous sources (MB ≤ -20) in two equal-volume redshift bins (0.4 ≤ z < 0.77 and 0.77 ≤…
A model of variability in Titan's atmospheric structure
Flasar, F. M.; Waite, J. H.; Lorenz, R. +2 more
Titan's atmosphere has been extensively studied during the Cassini-Huygens Mission. The polar environment undergoes considerable seasonal variation and is distinct from the more quiescent equatorial environment experienced by the Huygens probe in 2005. The thermal structure of the upper atmosphere is affected by interaction of Titan's atmosphere w…
Electric potential differences across auroral generator interfaces
De Keyser, J.; Echim, M.
Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated) depends on the properties of the plasmas on either side of the interface, as well as on the total electric potenti…
Advanced Spectral Library (ASTRAL): Cool stars edition
Ayres, T. R.
ASTRAL is a project to create high-resolution, high-S/N UV (1150-3200 Å) atlases of bright stars utilizing {HST}/STIS. During Cycle 18 (2010-2011), eight cool star targets were observed, including key objects like Procyon and Betelgeuse, churning through 146 orbits in the process. The new spectral atlases are publically available through the proje…
Enigmatic Recurrent Pulsational Variability of the Accreting White Dwarf EQ Lyn (SDSS J074531.92+453829.6)
Drake, A. J.; Hermes, J. J.; Montgomery, M. H. +19 more
Photometric observations of the cataclysmic variable EQ Lyn (SDSS J074531.92+453829.6), acquired from 2005 October to 2006 January, revealed high-amplitude variability in the range 1166-1290 s. This accreting white dwarf underwent an outburst in 2006 October, during which its brightness increased by at least five magnitudes, and it started exhibit…
Dispersion relation of electromagnetic ion cyclotron waves using Cluster observations
Walker, S. N.; Balikhin, M. A.; Shprits, Y. Y. +1 more
Multi-point wave observations on Cluster spacecraft are used to infer the dispersion relation of electromagnetic ion cyclotron (EMIC) waves. In this study we use a phase differencing method and observations from STAFF and WHISPER during a well-studied event of 30 March 2002. The phase differencing method requires the knowledge of the direction of …
G 10.472+0.027: An Extreme Water Maser Outflow Associated with a Massive Protostellar Cluster
Ellingsen, S. P.; Voronkov, M. A.; Breen, S. L. +2 more
An Australia Telescope Compact Array search for 22 GHz water masers toward 6.7 GHz class II methanol masers detected in the Methanol Multibeam survey has resulted in the detection of extremely high-velocity emission from one of the sources. The water maser emission associated with this young stellar object covers a velocity span of nearly 300 km s…
Spectral diagnostic of a microflare. Evidences of resonant scattering in C IV 1548 Å, 1550 Å lines
Gontikakis, C.; Patsourakos, S.; Winebarger, A. R.
Aims: We study a microflare, classified as a GOES-A1 after background subtraction, which was observed in active region NOAA 8541 on May 15, 1999.
Methods: We used TRACE filtergrams to study the morphology and time evolution. SUMER spectral lines were used to diagnose the chromospheric plasma (Si ii 1533 Å), transition region plasma (C iv…
Study of small-scale plasmoid structures in the magnetotail using Cluster observations and Hall MHD simulations
Feng, Xueshang; Ye, Yudong; Liu, Chaoxu +1 more
The existence of small-scale plasmoids associated with the Hall effect has been often observed in the magnetotail. They are considered as the signature of multiple X-line collisionless reconnection. To study these plasmoids structures, we present some Cluster observations and Hall MHD simulations of their features. In this study, the observation s…