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A review of the distance and structure of the Large Magellanic Cloud
Alves, David R.
The average of 14 recent measurements of the distance to the Large Magellanic Cloud (LMC) implies a true modulus of 18.50 ± 0.02 mag, and demonstrates a trend in the past 2 years of convergence toward a standard value. The distance indicators reviewed are the red clump, the tip of the red giant branch, Cepheid, RR Lyrae, and Mira variable stars, c…
The XMM-Newton Iron Line Profile of NGC 3783
Nandra, K.; Turner, T. J.; Reeves, J. N. +3 more
We report on observations of the iron K line in the nearby Seyfert 1 galaxy, NGC 3783, obtained in a long, two-orbit (~240 ks) XMM-Newton observation. The line profile obtained exhibits two strong narrow peaks at 6.4 and 7.0 keV, with measured line equivalent widths of 120 and 35 eV, respectively. The 6.4 keV emission is the Kα line from near neut…
A Constant Bar Fraction out to Redshift z ~ 1 in the Advanced Camera for Surveys Field of the Tadpole Galaxy
Elmegreen, Bruce G.; Elmegreen, Debra Meloy; Hirst, Amelia C.
Barlike structures were investigated in a sample of 186 disk galaxies larger than 0.5" that are in the I-band image of the Tadpole galaxy taken with the Hubble Space Telescope Advanced Camera for Surveys. We found 22 clear cases of barred galaxies, 21 galaxies with small bars that appear primarily as isophotal twists in a contour plot, and 11 case…
Cluster observations of earthward flowing plasmoid in the tail
Balogh, A.; Glassmeier, K. -H.; Zhang, H. +10 more
The energetic electrons and ions embedded in Earthward-moving plasmoid structures have been observed. These plasmoids are associated with a rotational local Bz component (bi-polar) signature. Energetic electrons are found to be confined in a smaller spatial region than ions inside the plasmoid. Energetic ions and electrons seem to be a …
The First IBIS/ISGRI Soft Gamma-Ray Galactic Plane Survey Catalog
Hill, A. B.; Walter, R.; Malaguti, G. +16 more
We report the first high-energy survey catalog obtained with the IBIS gamma-ray imager on board INTEGRAL. The analysis has been performed on the first-year Core Program ISGRI data comprising both Galactic Plane Scan and Galactic Centre Deep Exposure pointings for a total exposure time exceeding 5 Ms. This initial survey has revealed the presence o…
Abundances of Na, Mg and Al in nearby metal-poor stars
Zhao, G.; Liang, Y. C.; Shi, J. R. +2 more
To determine the population membership of nearby stars we explore abundance results obtained for the light neutron-rich elements 23Na and 27 Al in a small sample of moderately metal-poor stars. Spectroscopic observations are limited to the solar neighbourhood so that gravities can be determined from HIPPARCOS parallaxes, and …
The Globular Cluster Systems of the Early-Type Galaxies NGC 3379, NGC 4406, and NGC 4594 and Implications for Galaxy Formation
Zepf, Stephen E.; Rhode, Katherine L.
We have investigated the global properties of the globular cluster (GC) systems of three early-type galaxies: the Virgo Cluster elliptical NGC 4406, the field elliptical NGC 3379, and the field S0 galaxy NGC 4594. These galaxies were observed as part of a wide-field CCD survey of the GC populations of a large sample of normal galaxies beyond the L…
Solar and interplanetary sources of major geomagnetic storms during 1996-2002
Venkatakrishnan, P.; Srivastava, Nandita
During the 7-year period of the current solar cycle, 64 geoeffective coronal mass ejections (CMEs) were found to produce major geomagnetic storms (DST < -100 nT) at the Earth. In this paper we examine solar and interplanetary properties of these geoeffective coronal mass ejections (CMEs). The observations reveal that full-halo CMEs a…
An apparently normal γ-ray burst with an unusually low luminosity
Sunyaev, R. A.; Sazonov, S. Yu.; Lutovinov, A. A.
Much of the progress in understanding γ-ray bursts (GRBs) has come from studies of distant events (redshift z ~ 1). In the brightest GRBs, the γ-rays are so highly collimated that the events can be seen across the Universe. It has long been suspected that the nearest and most common events have been missed because they are not as collimated or the…
Band-splitting of coronal and interplanetary type II bursts. III. Physical conditions in the upper corona and interplanetary space
Magdalenić, J.; Vršnak, B.; Zlobec, P.
We analyse properties of 58 type II radio bursts recorded in the meter-to-kilometer wavelength range, focusing on episodes of band-split emission. The basic two parameters utilized are the frequency drift Df=df/dt and the relative band-split BDW=Δ f/f of type II burst emission lanes. On average, in the meter-to-kilometer wavelength rang…