Search Publications
Age-dating a star-burst with GEMINI/CIRPASS observations of the core of M83
Knapen, J. H.; Sharp, R. G.; Ryder, S. D. +2 more
We present preliminary results from a set of near-IR integral field spectroscopic observations of the central, star-burst, regions of the barred spiral galaxy M83, obtained with CIRPASS on Gemini-S. We present maps in the Paβ and [Fe{II}] ,1.257 µm emission lines which appear surprisingly different. We outline the procedure in which we will …
Evidence for chaotic dynamics in the Jovian magnetosphere
Sarris, E. T.; Anagnostopoulos, G. C.; Pavlos, G. P. +2 more
In this paper, for the first time we examine the hypothesis of chaotic behaviour for the dynamics of the inner of Jupiter's magnetosphere as which is appeared in energetic populations. For this, we study geometrical and dynamical characteristics of Jovian energetic ion time series in the reconstructed phase space by using the SVD extended chaotic …
An unusual high-ionization nebula in NGC 55
Rosa, M. R.; Tüllmann, R.
We report on the detection of a previously unknown extended low-density nebula of very high temperature and excitation, TR 001507.7-391206, located above the midplane of NGC 55. The nebular emission line spectrum, in which He II is present, is consistent with photoionization by about 3 very hot massive O3 or WR-type stars. There are no indications…
Initial mass function in the South-Western part of M 31
Borisov, G.; Nedialkov, P.; Veltchev, T.
We derive an average initial mass function (IMF) for 50 OB associations in the South-Western part of Andromeda galaxy, combining ultraviolet photometry of Hill et al. (\cite{Hill95}, ApJ, 98, 595) and two datasets HST photometry with JHKs photometry from the 2MASS + I band photometry from Magnier et al. (\cite{Magnier92}, A&A, 96, 3…
Properties of serendipitous X-ray flares discovered in XMM-Newton observations
Ramsay, Gavin; Trenholme, Duncan; Foley, Carl
We present the results of a search of the XMM-Newton public data archive for stellar X-ray flares. We find eight flaring sources for which we identify seven optical counterparts. Three of these sources have distance estimates which allow us to determine their luminosities. Based on the decay time of the flares and their luminosity, we derive loop …
Comparison of GONG and MDI solar p-mode background
Hill, F.; Barban, C.
Using Severino's model, we estimate the amount of coherent correlated and uncorrelated background and incoherent noise components needed to reproduce the following four helioseismic spectra: V power, I power, V-I phase difference and V-I coherence, using GONG and MDI data. We confirm that a coherent correlated component of 10-15% of the total back…
A new mechanism for the crab fingers
Carlqvist, P.
Images of the outer filamentary parts of the Crab Nebula, earlier obtained with the Hubble Space Telescope WFPC2, are reconsidered. On inspection of the images it is found that most of the mainly radially oriented fingers possess an internal structure, usually in the form of two or more filaments. For some of the fingers there are clear signs that…
Stereoscopic Spectroscopy for Efficient Spectral Imaging and Magnetography
DeForest, Craig; Elmore, D. F.; Bradford, M. P. +2 more
Stereoscopic imaging spectroscopy is a novel technique that uses multiple spectral orders and stereoscopic reconstruction to eliminate the need for a slit in a dispersive spectrograph, potentially increasing photon efficiency by 1-2 orders of magnitude compared with conventional spectral imaging. We present advances in stereoscopic reconstruction,…
Local wavelet correlation: applicationto timing analysis of multi-satellite CLUSTER data
Dudok de Wit, T.; Dunlop, M.; Soucek, J. +1 more
Multi-spacecraft space observations, such as those of CLUSTER, can be used to infer information about local plasma structures by exploiting the timing differences between subsequent encounters of these structures by individual satellites. We introduce a novel wavelet-based technique, the Local Wavelet Correlation (LWC), which allows one to match t…
Thinning and expansion of the substorm plasma sheet: Cluster PEACE timing analysis
Balogh, A.; Fazakerley, A.; Owen, C. +1 more
The storage and subsequent removal of magnetic flux in the magnetotail during a geomagnetic substorm has a dramatic effect on the thickness of the cross-tail plasma sheet. The near-Earth plasma sheet is thought to thin during the growth phase and then rapidly expand after onset of the substorm. The direction of propagation, whether earthward or ta…