Search Publications
Infrared Studies of Molecular Shocks in the Supernova Remnant HB21. I. Thermal Admixture of Shocked H2 Gas in the North
Koo, Bon-Chul; Lee, Ho-Gyu; Moon, Dae-Sik +2 more
We present near- and mid-infrared observations on the shock-cloud interaction region in the northern part of the supernova remnant HB21, performed with the infrared camera (IRC) aboard the AKARI satellite and the wide-field infrared camera (WIRC) at the Palomar 5 m telescope. The IRC 7 µm (S7), 11 µm (S11), and 15 µm (L15) band i…
A search for thermally emitting isolated neutron stars in the 2XMMp catalogue
Motch, C.; Pires, A. M.; Janot-Pacheco, E.
The relatively large number of nearby radio-quiet and thermally emitting isolated neutron stars (INSs) discovered in the ROSAT All-Sky Survey, dubbed the “Magnificent Seven”, suggests that they belong to a formerly neglected major component of the overall INS population. So far, attempts to discover similar INSs beyond the solar vicinity failed to…
Measurements of Absorption of Acoustic Waves in Sunspots with Direction Filters and Cross Correlation
Liang, Zhi-Chao; Chou, Dean-Yi; Sun, Ming-Tsung +1 more
Observations show that the power of solar acoustic waves is reduced inside magnetic regions. Several mechanisms, including absorption, emissivity reduction, and local suppression, may contribute to the observed power reduction in magnetic regions. So far there is no way to distinguish absorption from emissivity reduction in a magnetic region. In t…
3D Reconstruction of the Leading Edge of the 20 May 2007 Partial Halo CME
Mierla, M.; Inhester, B.; Srivastava, N. +1 more
We have reconstructed the leading edge of a coronal mass ejection (CME) observed on 20 May 2007 by COR1 and COR2 of the SECCHI suite onboard the twin STEREO spacecraft. The reconstruction of the leading edge of this CME was achieved using the tie-pointing method based on epipolar geometry. The true speeds derived from the reconstruction of the lea…
Superorbital variability in hard X-rays
Farrell, S. A.; Barret, D.; Skinner, G. K.
We present the results of a study with the Swift Burst Alert Telescope in the 14-195 keV range of the long-term variability of five low-mass X-ray binaries with reported or suspected superorbital periods - 4U 1636-536, 4U 1820-303, 4U 1916-053, Cyg X-2 and Sco X-1. No significant persistent periodic modulation was detected around the previously re…
Correlation properties of magnetosheath magnetic field fluctuations
Němeček, Z.; Gutynska, O.; Šafránková, J.
The magnetosheath is characterized by a variety of low-frequency fluctuations, but their features and sources are different. Taking advantage of multipoint magnetic field measurements of the Cluster spacecraft, we present a statistical study to reveal properties of waves. We compute cross-correlation coefficients of magnetic field strengths as mea…
The globular clusters-stellar haloes connection in early-type galaxies
Forte, Juan C.; Vega, E. Irene; Faifer, Favio
This paper explores if, and to what an extent, the stellar populations of early-type galaxies can be traced through the colour distribution of their globular cluster (GC) systems. The analysis, based on a galaxy sample from the Virgo Advanced Camera for Surveys data, is an extension of a previous approach that has been successful in the cases of t…
AK Sco, First Detection of a Highly Disturbed Atmosphere in a Pre-Main-Sequence Close Binary
Gómez de Castro, Ana I.
AK Sco is a unique source: a ~10 Myr old pre-main-sequence (PMS) spectroscopic binary composed of two nearly equal F5 stars that at periastron are separated by barely 11 stellar radii, so the stellar magnetospheres fill the Roche lobe at periastron. The orbit is not yet circularized (e = 0.47) and very strong tides are expected. This makes AK Sco …
Measurement of Low Signal-To-Noise Ratio Solar p-Modes in Spatially Resolved Helioseismic Data
Hill, F.; Appourchaux, T.; Salabert, D. +1 more
We present an adaptation of the rotation-corrected, m-averaged spectrum technique designed to observe low signal-to-noise ratio (S/N), low-frequency solar p-modes. The frequency shift of each of the 2l + 1 m spectra of a given (n, l) multiplet is chosen that maximizes the likelihood of the m-averaged spectrum. A high S/N can result from combining …
On distribution of CMEs speed in solar cycle 23
Mittal, Nishant; Sharma, Joginder; Tomar, Vivek +1 more
We have analyzed the data for more than 12900 coronal mass ejections (CMEs) which were obtained by SOHO/LASCO during the period of 1996-2007. The online CME catalogue contains all major CMEs detected by LASCO C2 and C3 coronagraphs. Basically we determine the CME speeds from the linear and quadratic fits to the height-time measurements. It is foun…