Search Publications
XMM-Newton study of the star forming region NGC 1333
Preibisch, T.
We analyze the data of a deep XMM-Newton X-ray imaging observation of the NGC 1333 star forming region. The observation covered a period of about 14 hours and has a total MOS-equivalent exposure time of 235 ksec. In addition to 46 bright X-ray sources revealed by source detection routines, we find weak X-ray emission at the positions of 40 X-ray s…
Sensitivity kernels for time-distance inversion based on the Rytov approximation
Pijpers, F. P.; Jensen, J. M.
The study of the solar convection zone has been given a new impetus with what promises to be a very powerful new tool in time-distance helioseismology (Duvall et al. \cite{DJHP93}). Using data obtained with this technique, it has become possible to do a tomographic reconstruction of structures in the convection zone. Most of the work done on inver…
The high-velocity outflow in the proto-planetary nebula Hen 3-1475
García-Lario, P.; Riera, A.; Manchado, A. +2 more
The proto-planetary nebula Hen 3-1475 shows a remarkable highly collimated optical jet with an S-shaped string of three pairs of knots and extremely high velocities. We present here a detailed analysis of the overall morphology, kinematic structure and the excitation conditions of these knots based on deep ground-based high dispersion spectroscopy…
STIS Spectral Imagery of the OB Stars in NGC 604. II. The Most Luminous Stars
Bruhweiler, Fred C.; Miskey, Cherie L.; Smith Neubig, Margaret
We present results using two-dimensional spectral imagery and photometry obtained with the Hubble Space Telescope (HST) for the starburst H II region NGC 604, in the nearby galaxy M33. The spectral imagery was acquired with the Space Telescope Imaging Spectrograph (STIS) using the MAMA-G140L configuration, which provided wavelength coverage spanni…
Properties of the solar velocity field indicated by motions of coronal bright points
Vršnak, B.; Wöhl, H.; Clette, F. +3 more
Full-disc solar images obtained with the Extreme Ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory (SOHO) are used to analyse properties of the solar velocity field by tracing coronal bright points from June 4, 1998 to May 22, 1999. Rotation velocity residuals, meridional motions and their relationship are investi…
The temperature and distribution of gas in CL 0016+16 measured with XMM-Newton
Birkinshaw, M.; Worrall, D. M.
We present the results of a 37-ks observation of CL 0016+16 with the XMM-Newton EPIC instrument. Within 1.5 arcmin of the cluster centre we measured a gas temperature of kT= 9.13+0.24-0.22 keV and an abundance of 0.22+0.04-0.03 times the solar value (1σ uncertainties). This significant improvement over p…
XMM-Newton study of the Serpens star-forming region
Preibisch, T.
We analyze a XMM-Newton X-ray observation of the Serpens dark cloud with a total MOS-equivalent exposure time of 57 ksec. We find 45 individual X-ray sources. None of the class 0 protostars, only one of the class I protostars, and two of the flat-spectrum objects in the region are detected in X-rays. The optically invisible flat-spectrum source EC…
Soho observations relating to the association between flares and coronal mass ejections
Harrison, R. A.
Campaigns to investigate the solar coronal mass ejection (CME) onset have been run using the Solar andHeliospheric Observatory (SOHO) since 1996. These have included coronagraph and extreme-ultraviolet (EUV) disc imaging, along with magnetic mapping of the photosphere, in concert with EUV and UV spectroscopic observations. These campaigns have inc…
Discovery of the eclipse in the symbiotic binary Z Andromedae
Skopal, A.
Our photometric observations of the symbiotic binary Z And during its recent (2000-2003) active phase revealed a minimum in the U, B and V light curves (LC) at the position of the inferior conjunction of its cool component (the orbital phase varphi = 0). This fact and the behaviour of colour indices suggest that the minimum was due to the eclipse …
When will Voyager 1 and 2 cross the termination shock?
Gloeckler, George; Izmodenov, Vlad; Malama, Yuri
Our Solar System moves through a warm (~6,500 K), partly ionized local interstellar cloud (LIC) with a relative speed of ~26 km/s. The solar wind interacts with the LIC to form a cavity around the Sun called the heliosphere. The solar wind meets the interstellar charged component at the heliopause, where solar wind pressure balances the pressure o…