Search Publications
The Mass-Lx Relation for Moderate Luminosity X-ray Clusters
McNamara, Brian R.; Donahue, Megan; Voit, G. Mark +2 more
We present measurements of the masses of a sample of 25 moderate X-ray luminosity clusters of galaxies from the 160 square degree ROSAT survey. The masses were obtained from a weak-lensing analysis of deep F814W images obtained using the Advanced Camera for Surveys. We present an accurate empirical correction for the effect of charge transfer (in)…
Hubble Space Telescope Imaging of Lyα Emission at z ≈ 4.4
Finkelstein, Steven L.; Grogin, Norman A.; Hathi, Nimish P. +28 more
We present the highest redshift detections of resolved Lyα emission, using Hubble Space Telescope (HST)/Advanced Camera for Surveys F658N narrowband-imaging data taken in parallel with the Wide Field Camera 3 Early Release Science program in the GOODS Chandra Deep Field-South. We detect Lyα emission from three spectroscopically confirmed z = 4.4 L…
Different Patterns of Chromospheric Evaporation in a Flaring Region Observed with Hinode/EIS
Ding, M. D.; Li, Y.
We investigate the chromospheric evaporation in the flare of 2007 January 16 using line profiles observed by the Exterme-UV Imaging Spectrometer on board Hinode. Three points at flare ribbons of different magnetic polarities are analyzed in detail. We find that the three points show different patterns of upflows and downflows in the impulsive phas…
Did the Sun Change Its Behaviour During the Decline of Cycle 23 and Into Cycle 24?
Tapping, K. F.; Valdés, J. J.
The activity minimum between the end of cycle 23 and the beginning of cycle 24 was the longest and deepest since at least the beginning of the 20th century. This has led to speculation that the Sun is changing its behaviour. The sunspot number and 10.7-cm solar radio flux indices have traditionally been highly correlated, so a change in the relati…
Can coronal hole spicules reach coronal temperatures?
Doyle, J. G.; Madjarska, M. S.; Vanninathan, K.
Aims: The present study aims to provide observational evidence of whether coronal hole spicules reach coronal temperatures.
Methods: We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode.
Results: The analysed three large spicules were found to be comprised of numerous thin spicules…
A mid-IR study of Hickson compact groups. II. Multiwavelength analysis of the complete GALEX-Spitzer sample
Le Floc'h, E.; Magdis, G.; da Cunha, E. +3 more
We present a comprehensive study of the impact of the environment of compact galaxy groups on the evolution of their members using a multiwavelength analysis from the ultraviolet to the infrared, for a sample of 32 Hickson compact groups (HCGs) containing 135 galaxies. Fitting the spectral energy distributions (SEDs) of all galaxies with the state…
Long-term spectral and timing properties of the soft gamma-ray repeater SGR 1833-0832 and detection of extended X-ray emission around the radio pulsar PSR B1830-08
Sakamoto, T.; Wieringa, M. H.; Tiengo, A. +19 more
SGR 1833-0832 was discovered on 2010 March 19, thanks to the Swift detection of a short hard X-ray burst and follow-up X-ray observations. Since then, it was repeatedly observed with Swift, Rossi X-ray Timing Explorer and XMM-Newton. Using these data, which span about 225 d, we studied the long-term spectral and timing characteristics of SGR 1833-…
Evolution of sunspot properties during solar cycle 23
Fletcher, L.; Marshall, S.; Watson, F. T.
Context. The long term study of the Sun is necessary if we are to determine the evolution of sunspot properties and thereby inform modeling of the solar dynamo, particularly on scales of a solar cycle.
Aims: We aim to determine a number of sunspot properties over cycle 23 using the uniform database provided by the SOHO Michelson Doppler Image…
The Solar Energetic Balance Revisited by Young Solar Analogs, Helioseismology, and Neutrinos
Turck-Chièze, Sylvaine; Couvidat, Sébastien; Piau, Laurent
The energetic balance of the standard solar model (SSM) results from equilibrium between nuclear energy production, energy transfer, and photospheric emission. In this Letter, we give an order of magnitude of several percent for the loss of energy in kinetic energy, magnetic energy, and X-ray or UV radiation during the entire solar lifetime from t…
Sympathetic Filament Eruptions Connected by Coronal Dimmings
Yang, Jiayan; Bi, Yi; Hong, Junchao +2 more
We present for the first time detailed observations of three successive, interdependent filament eruptions that occurred one by one within 5 hr from different locations beyond the range of a single active region. The first eruption was observed from an active region and was associated with a coronal mass ejection (CME), during which diffuse and co…