Search Publications
The nature of the molecular gas system in the core of NGC 1275
Edge, A. C.; Johnstone, R. M.; Wilman, R. J.
We present near-infrared integral field spectroscopy of the central kiloparsec of NGC 1275 at the heart of the Perseus cluster of galaxies, obtained with the Integral Field Unit (IFU) of the United Kingdom Infrared Telescope (UKIRT) Imaging Spectrometer (UIST). The nuclear ro-vibrational H2 emission is spatially resolved and is likely t…
Crystalline Silicates
Kemper, Ciska; Molster, Frank
One of the big surprises of the Infrared Space Observatory (ISO) has been discovery of crystalline silicates outside our own Solar system. It was generally assumed before that all cosmic silicates in space were of amorphous structure. Thanks to ISO we know now that crystalline silicates are ubiquitous in the Galaxy (except for the diffuse ISM) and…
Energetic particle injections in Saturn's magnetosphere
Krupp, N.; Krimigis, S. M.; Mitchell, D. G. +9 more
Measurements from the Cassini Magnetospheric Imaging Instrument (MIMI) beginning in July 2004 reveal that sudden planetward injections of energetic ions (5-200 keV) and electrons (20-200 keV) over confined regions of azimuth are pervasive events in Saturn's magnetosphere over the radial range of 3.8 to 11.2 Saturn radii (RS). Saturn is …
A highly-ionized absorber in the X-ray binary 4U 1323-62: A new explanation for the dipping phenomenon
Kaastra, J. S.; Díaz Trigo, M.; Parmar, A. N. +2 more
We report the detection of narrow Fe XXV and Fe XXVI X-ray absorption lines at 6.68 ± 0.04 keV and 6.97 ± 0.05 keV in the persistent emission of the dipping low-mass X-ray binary 4U 1323-62 during a 2003 January XMM-Newton observation. These features are superposed on a broad emission feature centered on 6.6 +0.1-0.2 keV. Dur…
A Chandra Study of the Multicomponent X-Ray Emission from the X-shaped Radio Galaxy 3C 403
Hardcastle, M. J.; Worrall, D. M.; Murray, S. S. +1 more
We present results from a 49.4 ks Chandra ACIS-S observation of the nearby (z=0.059) X-shaped FR type II (FR II) radio galaxy 3C 403. This is the first Chandra observation of an X-shaped radio galaxy, and one of the goals of this pioneering study is to determine the relationship between the X-ray-emitting gas and the X-shaped radio morphology. We …
The first observed stellar X-ray flare oscillation: Constraints on the flare loop length and the magnetic field
Mitra-Kraev, U.; Harra, L. K.; Williams, D. R. +1 more
We present the first X-ray observation of an oscillation during a stellar flare. The flare occurred on the active M-type dwarf
The Opacity of Spiral Galaxy Disks. IV. Radial Extinction Profiles from Counts of Distant Galaxies Seen through Foreground Disks
Allen, Ronald J.; Holwerda, B. W.; van der Kruit, P. C. +1 more
Dust extinction can be determined from the number of distant field galaxies seen through a spiral disk. To calibrate this number for the crowding and confusion introduced by the foreground image, González et al. and Holwerda et al. developed the Synthetic Field Method (SFM), which analyzes synthetic fields constructed by adding various deep exposu…
Drift-Kinetic Alfvén Waves Observed near a Reconnection X Line in the Earth's Magnetopause
Balogh, A.; Reme, H.; Goldstein, M. L. +7 more
We identify drift-kinetic Alfvén waves in the vicinity of a reconnection X line on the Earth’s magnetopause. The dispersive properties of these waves have been determined using wavelet interferometric techniques applied to multipoint observations from the Cluster spacecraft. Comparison of the observed wave dispersion with that expected for drift-k…
An X-Ray Variable Millisecond Pulsar in the Globular Cluster 47 Tucanae: Closing the Link to Low-Mass X-Ray Binaries
Bogdanov, Slavko; van den Berg, Maureen; Grindlay, Jonathan E.
We report the discovery of peculiar X-ray spectral variability in the binary radio millisecond pulsar PSR J0024-7204W in the globular cluster 47 Tuc. The observed emission consists of a dominant nonthermal component, which is eclipsed for a portion of the orbit, and a thermal component, which appears to be persistent. We propose that the nontherma…
Size distribution of circumstellar disks in the Trapezium cluster
Alves, J.; Vicente, S. M.
In this paper we present results on the size distribution of circumstellar disks in the