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Determination of the 3D structure of an EUV-filament observed by SoHO/CDS, SoHO/SUMER and VTT/MSDP
Heinzel, P.; Anzer, U.; Schmieder, B. +1 more
Heinzel et al. (\cite{hein1}) found that filaments seem to be much more extended in EUV spectral lines than in Hα. In this paper we reconstruct the 3D structure of the extensions of the EUV-filament observed on 15 October 1999 by SoHO/CDS and SoHO/SUMER. Small Hα structures were observed by VTT/MSDP. We computed the bottom and top heights of the E…
Strong Gravitational Lens Candidates in the GOODS ACS Fields
Ferguson, H. C.; Moustakas, L. A.; Lucas, R. A. +3 more
We present results from a systematic search for strong gravitational lenses in the Great Observatories Origins Deep Survey (GOODS) Advanced Camera for Surveys (ACS) data. The search technique involves creating a sample of likely lensing galaxies, which we define as massive early-type galaxies in a redshift range 0.3<z<1.3. The target galaxie…
Chandra and XMM-Newton observations of NGC 4214: the hot interstellar medium and the luminosity function of dwarf starbursts
Heckman, Timothy M.; Stevens, Ian R.; Hartwell, Joanna M. +2 more
We present results from Chandra and XMM-Newton X-ray observations of NGC 4214, a nearby dwarf starburst galaxy containing several young regions of very active star-formation. Starburst regions are known to be associated with diffuse X-ray emission, and in this case the X-ray emission from the galaxy shows an interesting morphological structure wit…
Keck Spectroscopy of Red Giant Stars in the Vicinity of M31'S Massive Globular Cluster G1
Rich, R. Michael; Guhathakurta, Puragra; Reitzel, David B.
We present results from an ongoing Keck spectroscopic survey of red giant stars in a field located along the major axis of M31, ~34 kpc in projection from the nucleus and near the luminous globular cluster G1. We use multislit LRIS spectroscopy to measure the Ca II near-infrared triplet in 41 stars ranging in apparent magnitude from 20<I<22.…
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 …