Search Publications
Globular Clusters and X-Ray Point Sources in Centaurus A (NGC 5128)
Jordán, Andrés; Raychaudhury, Somak; Whitaker, Katherine E. +6 more
We detect 353 X-ray point sources, mostly low-mass X-ray binaries (LMXBs), in four Chandra observations of Centaurus A (NGC 5128), the nearest giant early-type galaxy, and correlate this point-source population with the largest available ensemble of confirmed and likely globular clusters (GCs) associated with this galaxy. Of the X-ray sources, 31 …
An AKARI Search for Intracluster Dust of Globular Clusters
Yamamura, Issei; Matsunaga, Noriyuki; Mito, Hiroyuki +7 more
We report on observations of 12 globular clusters with the Far-Infrared Surveyor (FIS) aboard the AKARI satellite. Our goal is to search for emission from cold dust within clusters. We detected diffuse emissions toward NGC6402 and 2808, but the IRAS 100µm maps show the presence of strong background radiation. They are likely to have been emi…
Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts Observed by the Suzaku-WAM and the Konus-Wind
Yamaoka, Kazutaka; Fukazawa, Yasushi; Ohno, Masanori +16 more
We have performed a joint analysis of prompt emission from four bright short gamma-ray bursts (GRBs) with the Suzaku-WAM and the Konus-Wind experiments. This joint analysis allows us to investigate the spectral properties of short-duration bursts over a wider energy band with a higher accuracy. We find that these bursts have a high Epeak
Unusual Zebra Patterns in the Decimeter Wave Band
Tan, Chengming; Yan, Yihua; Chernov, G. P. +2 more
An analysis of new observations showing fine structures consisting of narrowband fiber bursts as substructures of large-scale zebra-pattern stripes is carried out. We study four events using spectral observations taken with a newly built spectrometer located at the Huairou station, China, in the frequency range of 1.1 - 2.0 GHz with extremely high…
Derivation of inner magnetospheric electric field (UNH-IMEF) model using Cluster data set
Khotyaintsev, Y.; Torbert, R. B.; Matsui, H. +3 more
We derive an inner magnetospheric electric field (UNH-IMEF) model at L=2 10 using primarily Cluster electric field data for more than 5 years between February 2001 and October 2006. This electric field data set is divided into several ranges of the interplanetary electric field (IEF) values measured by ACE. As ring current simulations which requir…
Gomez's Hamburger (IRAS 18059-3211): a pre main-sequence A-type star
Bujarrabal, V.; Young, K.; Fong, D.
Aims: We study the nature of Gomez's Hamburger (IRAS 18059-3211; GoHam), a nebula that has been proposed to be a post-AGB object. Such a classification has not been confirmed; instead, we argue that it will be a key object in the study of disks rotating around young stars.
Methods: We present high-resolution SMA maps of CO J = 2-1 in Gomez's H…
Automatic Recognition and Characterisation of Supergranular Cells from Photospheric Velocity Fields
Potts, H. E.; Diver, D. A.
We have developed an exceptionally noise-resistant method for accurate and automatic identification of supergranular cell boundaries from velocity measurements. Because of its high noise tolerance the algorithm can produce reliable cell patterns with only very small amounts of smoothing of the source data in comparison to conventional methods. In …
Magnetized Mars: Transformation of Earth-like magnetosphere to Venus-like induced magnetosphere
Kallio, E.; Janhunen, P.; Barabash, S. +1 more
Using a global numerical model, we have studied how the present Martian magnetosphere may have looked in the past when the planet had a global intrinsic magnetic field. A Mars version (HYB-Mars) of the self-consistent quasi-neutral hybrid model was used which treats the ions as particles and the electrons as a massless charge-neutralizing fluid. W…
INTEGRAL observations of PSR J1811-1925 and its associated pulsar wind nebula
de Rosa, A.; Hill, A. B.; Bird, A. J. +6 more
We present spectral measurements made in the soft (20-100keV) γ-ray band of the region containing the composite supernova remnant G11.2-0.3 and its associated pulsar PSR J1811-1925. Analysis of INTEGRAL/IBIS data allows characterization of the system above 10keV. The IBIS spectrum is best fitted by a power law having photon index Γ = 1.8+0.4<…
Cassini RADAR constraint on Titan's winter polar precipitation
Lorenz, R. D.; West, R. D.; Johnson, W. T. K.
The Cassini RADAR instrument made a dedicated cloud backscatter observation near Titan's north pole, presently in winter darkness, to constrain the precipitation of material onto the surface. The detection limit is ∼5 orders of magnitude above that expected in methane rainstorms, and rules out 'drizzle' of more than ∼10cm/yr, placing constraints o…