Search Publications

On the Inversion of Stokes Profiles with Local Stray-light Contamination

Asensio Ramos, A.; Manso Sainz, R.

Obtaining the magnetic properties of non-resolved structures in the solar photosphere is always challenging and problems arise because the inversion is carried out through the numerical minimization of a merit function that depends on the proposed model. We investigate the reliability of inversions in which the stray-light contamination is obtaine…

Correlation Analyses Between the Characteristic Times of Gradual Solar Energetic Particle Events and the Properties of Associated Coronal Mass Ejections

Wang, Yuming; Wang, C. B.; Pan, Z. H. +1 more

It is generally believed that gradual solar energetic particles (SEPs) are accelerated by shocks associated with coronal mass ejections (CMEs). Using an ice-cream cone model, the radial speed and angular width of 95 CMEs associated with SEP events during 1998 - 2002 are calculated from SOHO/LASCO observations. Then, we investigate the relationship…

A Census of Mid-infrared-selected Active Galactic Nuclei in Massive Galaxy Clusters at 0 <~ z <~ 1.3

Saintonge, Amélie; Tran, Kim-Vy H.; Tomczak, Adam R.

We conduct a deep mid-infrared (mid-IR) census of nine massive galaxy clusters at (0 < z < 1.3) with a total of ~1500 spectroscopically confirmed member galaxies using Spitzer/IRAC photometry and established mid-IR color selection techniques. Of the 949 cluster galaxies that are detected in at least three of the four IRAC channels at the >…

Long-period variables in the CoRoT fields

Lebzelter, T.

Aims: We searched the first set of data released by the CoRoT mission for red stars showing long-period variability (LPV). These stars are likely highly evolved stars on the upper giant branch. The high time resolution of the CoRoT data allows us to study the light curves of these variables in unprecedented detail.
Methods: Light curves …

Spatial dependence of magnetopause energy transfer: Cluster measurements verifying global simulations

Dandouras, I.; Lucek, E. A.; Dunlop, M. +4 more

We investigate the spatial variation of magnetopause energy conversion and transfer using Cluster spacecraft observations of two magnetopause crossing events as well as using a global magnetohydrodynamic (MHD) simulation GUMICS-4. These two events, (16 January 2001, and 26 January 2001) are similar in all other aspects except for the sign of the i…

Simple stellar population models including blue stragglers

Deng, Licai; de Grijs, Richard; Kroupa, Pavel +1 more

Observations show that nearly all star clusters and stellar populations contain blue straggler stars (BSs). BSs in a cluster can significantly enhance the integrated spectrum of the host population, preferentially at short wavelengths, and render it much bluer in photometric colours. Current theoretical simple stellar population (SSP) models const…

A pilot study for the SCUBA-2 `All-Sky' Survey

Ivison, R. J.; Hill, T.; Berry, David +31 more

We have carried out a pilot study for the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) ‘All-Sky’ Survey (SASSy), a wide and shallow mapping project at 850 µm, designed to find rare objects, both Galactic and extragalactic. Two distinct sets of exploratory observations were undertaken and used to test the SASSy approach and data-redu…

Chandra and HST Studies of the X-Ray Sources in Galactic Globular Cluster M92

Anderson, Scott F.; Kong, Albert K. H.; Verbunt, Frank +3 more

We present the analysis of two observations of M92 taken with the Chandra X-Ray Observatory. We combined the two data sets with a total exposure of ~52 ks. With the combined observation, we detected 10 X-ray sources inside the half-mass radius (1farcm02), five of which are inside the core radius (0farcm26) of M92. The luminosities of the 10 source…

Instrumental phase-based method for Fourier transform spectrometer measurements processing

Scaccabarozzi, Diego; Saggin, Bortolino; Tarabini, Marco

Size and amplitude of Langmuir waves in the solar wind

Malaspina, D. M.; Hess, S. L. G.; Ergun, R. E.

Langmuir waves in the solar wind are known to be the origin of many types of solar radio emissions. In situ observations have shown that the most intense Langmuir waves often appear as wave packets. Several models have been proposed to explain this localization, such as kinetic localization and eigenmode formation. In the present paper we investig…