Search Publications
High-energy observations of the state transition of the X-ray nova and black hole candidate XTE J1720-318
Frontera, F.; Goldoni, P.; Parmar, A. N. +13 more
We report the results of extensive high-energy observations of the X-ray transient and black hole candidate XTE J1720-318 performed with INTEGRAL, XMM-Newton and RXTE. The source, which underwent an X-ray outburst in 2003 January, was observed in February in a spectral state dominated by a soft component with a weak high-energy tail. The XMM-Newto…
Polar magnetic flux on the Sun in 1996-2003 from SOHO/MDI data
Benevolenskaya, E. E.
Polarity of the polar magnetic fields on the Sun changes in every 11-year sunspot cycle, affecting the large-scale structure of the corona and heliosphere. Using the SOHO/MDI data, the flux of the radial component of the magnetic field is estimated for different latitudinal zones. It is estimated that the total magnetic flux of the Northern polar …
On the Formation of Extreme-Ultraviolet Helium Lines in the Sun: Analysis of SOHO Data
Judge, Philip G.; Pietarila, Anna
The resonance lines of helium in the Sun are several times stronger than expected, relative to lines of other ions. To explore the origins of this ``helium enhancement,'' we have studied data from the SUMER, CDS, MDI, and EIT instruments on the Solar and Heliospheric Observatory (SOHO). Time series data obtained in a quiet region and a coronal hol…
The properties of Lyman break galaxies at z~ 5
Hardcastle, M. J.; Bremer, M. N.; Lehnert, M. D. +3 more
In a recent paper, Lehnert & Bremer have photometrically selected a sample of Lyman break galaxies at z > 4.8 from a single VLT/FORS2 pointing and spectroscopically confirmed half of them to be at 4.8 < z < 5.8. To study the properties of such galaxies further, we have photometrically selected a similar sample (VAB > 28,…
Multi-frequency study of extragalactic supernova remnants and H II regions. Sculptor group Sd galaxy NGC 300
White, G. L.; Filipović, M. D.; Payne, J. L. +4 more
We present a multi-frequency study of supernova remnants (SNRs) and H I I regions in the nearby Sculptor Group Sd galaxy NGC 300, based on new ATCA observations at the wavelengths of 13 and 20 cm, XMM-Newton observations, newly-processed ROSAT (PSPC/HRI; \citealt{read}) and VLA (20/6 cm) images of this galaxy. We have investigated the physical pro…
The Magnetic Structure of Hα Macrospicules in Solar Coronal Holes
Wang, H.; Moore, R. L.; Suess, S. T. +2 more
Measurements by Ulysses in the high-speed polar solar wind have shown the wind to carry some fine-scale structures in which the magnetic field reverses direction by having a switchback fold in it. The lateral span of these magnetic switchbacks, translated back to the Sun, is of the scale of the lanes and cells of the magnetic network in which the …
Magnetostatic Structures of the Solar Corona. III. Normal and Inverse Quiescent Prominences
Zhang, M.; Low, B. C.
Analytical solutions describing equilibrium magnetic fields in the solar corona, deformed by prominence-like plasma condensations in the Cartesian plane, are treated in this paper. The equilibrium equations for this class of problems usually take different forms in distinct subdomains, separated by free boundaries to be solved as one of the unknow…
Tiny-scale molecular structures in the Magellanic Clouds. I. FUSE, HST and VLT observations
Le Petit, F.; Roueff, E.; André, M. K. +6 more
The objective of this series of two papers is to investigate small-scale molecular structures in the Magellanic Clouds (hereafter MCs). We report on the FUSE detections of the HD and CO molecules on the lines of sight towards three Large Magellanic stars: Sk -67D05, Sk -68D135, and Sk -69D246. HD is also detected for the first time on the lines of…
Methane Abundance Variations toward the Massive Protostar NGC 7538 IRS 9
Blake, G. A.; Boogert, A. C. A.; Öberg, K.
Absorption and emission lines originating from the ν3 CH stretching manifold of gas-phase CH4 were discovered in the high-resolution (R=25,000) infrared L-band spectrum along the line of sight toward NGC 7538 IRS 9. These observations provide a diagnostic of the complex dynamics and chemistry in a massive star-forming region.…
On the Coronal Mass Ejection onset and Coronal Dimming
Howard, Timothy A.; Harrison, Richard A.
A comprehensive case and statistical study of CME onsets has been conducted on the solar limb using the CDS, LASCO and EIT instruments aboard the SOHO spacecraft. This is the first dedicated campaign to establish firmly the EUV signatures of CME onsets and is based on a series of low-corona observing campaigns made in 2002. The event database cons…