Search Publications
Globular Clusters in the Outer Galactic Halo: AM-1 and Palomar 14
Dotter, Aaron; Sarajedini, Ata; Yang, Soung-Chul
AM-1, at ~120 kpc, and Palomar 14 (Pal 14), at ~70 kpc, are two of the most distant Galactic globular clusters (GCs) known. We present Hubble Space Telescope Wide Field Planetary Camera 2 photometry of AM-1 and Pal 14 that reveals unprecedented depth and detail in the color-magnitude diagrams of these two clusters. Absolute and relative age measur…
CME Earthward Direction as an Important Geoeffectiveness Indicator
Cho, K. -S.; Kim, K. -H.; Moon, Y. -J. +7 more
Frontside halo coronal mass ejections (CMEs) are generally considered as potential candidates for producing geomagnetic storms, but there was no definite way to predict whether they will hit the Earth or not. Recently Moon et al. suggested that the degree of CME asymmetries, as defined by the ratio of the shortest to the longest distances of the C…
The Solar Wind Power from Magnetic Flux
McComas, D. J.; Schwadron, N. A.
Observations of the fast, high-latitude solar wind throughout Ulysses' three orbits show that solar wind power correlates remarkably well with the Sun's total open magnetic flux. These observations support a recent model of the solar wind energy and particle sources, where magnetic flux emergence naturally leads to an energy flux proportional to t…
Magnetic Causes of the Eruption of a Quiescent Filament
Golub, L.; Bommier, V.; Schmieder, B. +5 more
During the JOP178 campaign in August 2006, we observed the disappearance of our target, a large quiescent filament located at S25°, after an observation time of three days (24 August to 26 August). Multi-wavelength instruments were operating: THEMIS/MTR ("MulTi-Raies") vector magnetograph, TRACE ("Transition Region and Coronal Explorer") at 171 Å …
Weighing the black holes in ultraluminous X-ray sources through timing
Belloni, T.; Ponti, G.; Miniutti, G. +3 more
We describe a new method to estimate the mass of black holes in Ultraluminous X-ray Sources (ULXs). The method is based on the recently discovered `variability plane', populated by Galactic stellar-mass black-hole candidates (BHCs) and supermassive active galactic nuclei (AGNs), in the parameter space defined by the black-hole mass, accretion rate…
Mirror-mode-like structures in Venus' induced magnetosphere
Zhang, T. L.; Glassmeier, K. -H.; Baumjohann, W. +3 more
The solar wind interaction with Venus creates an induced magnetosphere around the planet. It is shown that within the space bound by Venus' bow shock and ionopause, there is a rich occurrence of mirror-mode-like structures in the magnetic field data. The dayside magnetosheath and nightside magnetosheath/wake regions are investigated separately. It…
A statistical study of hot flow anomalies using Cluster data
Dandouras, I.; Daly, P. W.; Facskó, G. +3 more
Hot flow anomalies (HFAs) are studied using observations of the RAPID suprathermal charged particle detector, the FGM magnetometer, and the CIS plasma detector aboard the four Cluster spacecraft. Previously, we studied several specific features of tangential discontinuities on the basis of Cluster measurements in February-April 2003. In this paper…
Resolving the circumbinary dust disk surrounding HH 30
Pety, J.; Gueth, F.; Guilloteau, S. +1 more
Context: The jet-disk connection is an important part of the star formation process. HH 30 is a rare and beautiful example of a system exhibiting a flared edge-on disk, an optical jet and a CO molecular outflow. A recent analysis of the jet wiggling has revealed that the central star is in reality a binary object. Therefore, the dust and gas disk …
Measuring the Broad-Band X-Ray Spectrum from 400eV to 40keV in the Southwest Part of the Supernova Remnant RXJ1713.7-3946
Petre, Robert; Kokubun, Motohide; Nakazawa, Kazuhiro +13 more
We report on results from Suzaku broadband X-ray observations of the southwest part of the galactic supernova remnant (SNR) RXJ1713.7-3946 with an energy coverage of 0.4-40keV. The X-ray spectrum, presumably of synchrotron origin, is known to be completely lineless, making this SNR ideally suited for a detailed study of the X-ray spectral shape fo…
New Hubble Space Telescope imaging of the counterparts to six ultraluminous X-ray sources
Roberts, T. P.; Levan, A. J.; Goad, M. R.
We report the results of new Hubble Space Telescope imaging of the positions of six ultraluminous X-ray sources (ULXs). Using images in three Advanced Camera for Surveys (ACS) filters, we detect good candidate counterparts to four out of six ULXs, with one more possible detection, and observed magnitudes in the range m ~ 22-26 in the F606W filter.…