Search Publications

Single-spacecraft detection of rolled-up Kelvin-Helmholtz vortices at the flank magnetopause
DOI: 10.1029/2006JA011728 Bibcode: 2006JGRA..111.9203H

RèMe, H.; Hasegawa, H.; Fujimoto, M. +3 more

Recent numerical simulations suggest that as soon as the Kelvin-Helmholtz instability (KHI) has grown nonlinearly to form a highly rolled-up vortex, plasma mixing is inevitably achieved within the vortex. Identification of rolled-up vortices by in situ measurements is therefore an important task as a step to establish the mechanism by which solar …

2006 Journal of Geophysical Research (Space Physics)
Cluster 155
Spitzer IRAC Confirmation of z850-Dropout Galaxies in the Hubble Ultra Deep Field: Stellar Masses and Ages at z ~ 7
DOI: 10.1086/508512 Bibcode: 2006ApJ...649L..67L

Labbé, Ivo; Illingworth, G. D.; Franx, M. +1 more

Using Spitzer IRAC mid-infrared imaging from the Great Observatories Origins Deep Survey, we study z850-dropout sources in the Hubble Ultra Deep Field. After carefully removing contaminating flux from foreground sources, we clearly detect two z850 dropouts at 3.6 and 4.5 µm, while two others are marginally detected. The…

2006 The Astrophysical Journal
eHST 154
Ground-based CCD astrometry with wide field imagers. I. Observations just a few years apart allow decontamination of field objects from members in two globular clusters
DOI: 10.1051/0004-6361:20065004 Bibcode: 2006A&A...454.1029A

Anderson, J.; Bedin, L. R.; Piotto, G. +2 more

This paper is the first of a series of papers in which we will apply the methods we have developed for high-precision astrometry (and photometry) with the Hubble Space Telescope (HST) to the case of wide-field ground-based images. In particular, we adapt the software originally developed for WFPC2 to ground-based, wide field images from the WFI at…

2006 Astronomy and Astrophysics
eHST 153
Discovery of an Extraordinarily Massive Cluster of Red Supergiants
DOI: 10.1086/503275 Bibcode: 2006ApJ...643.1166F

MacKenty, John W.; Figer, Donald F.; Kudritzki, Rolf P. +4 more

We report the discovery of an extraordinarily massive young cluster of stars in the Galaxy, having an inferred total initial cluster mass comparable to the most massive young clusters in the Galaxy. Using IRMOS, 2MASS, and Spitzer observations, we conclude that there are 14 red supergiants in the cluster, compared with five, in what was previously…

2006 The Astrophysical Journal
INTEGRAL 153
The Morphological Diversities among Star-forming Galaxies at High Redshifts in the Great Observatories Origins Deep Survey
DOI: 10.1086/507016 Bibcode: 2006ApJ...652..963R

Papovich, Casey; Dickinson, Mark; Ferguson, Henry C. +8 more

We used the deep, multiwavelength images obtained by the Great Observatories Origins Deep Survey (GOODS) to identify ~4700 Lyman break galaxies (LBGs) at z>2.5, and 292 starburst galaxies at z~1.2. We present the results from morphological analysis based on light profile shape and ellipticity for ~1333 of the most luminous LBGs. About 40% of LB…

2006 The Astrophysical Journal
eHST 153
The Calm before the Storm: The Link between Quiescent Cavities and Coronal Mass Ejections
DOI: 10.1086/500446 Bibcode: 2006ApJ...641..590G

de Toma, G.; Gibson, S. E.; Burkepile, J. +2 more

Determining the state of the corona prior to CMEs is crucial to understanding and ultimately predicting solar eruptions. A common and compelling feature of CMEs is their three-part morphology, as seen in white-light observations of a bright expanding loop, followed by a relatively dark cavity, and finally a bright core associated with an erupting …

2006 The Astrophysical Journal
SOHO 152
Unveiling the nature of INTEGRAL objects through optical spectroscopy. V. Identification and properties of 21 southern hard X-ray sources
DOI: 10.1051/0004-6361:20066055 Bibcode: 2006A&A...459...21M

Palazzi, E.; Minniti, D.; Masetti, N. +13 more

Optical spectroscopic identification of the nature of 21 unidentified southern hard X-ray objects is reported here in the framework of our campaign aimed at determining the nature of newly-discovered and/or unidentified sources detected by INTEGRAL. Our results show that 5 of these objects are magnetic Cataclysmic Variables (CVs), 4 are High-Mass …

2006 Astronomy and Astrophysics
INTEGRAL 150
Dynamical Properties of Ultraluminous Infrared Galaxies. I. Mass Ratio Conditions for ULIRG Activity in Interacting Pairs
DOI: 10.1086/499068 Bibcode: 2006ApJ...638..745D

Lutz, D.; Genzel, R.; Tacconi, L. J. +6 more

We present first results from our Very Large Telescope large program to study the dynamical evolution of ultraluminous infrared galaxies (ULIRGs), which are the products of mergers of gas-rich galaxies. The full data set consists of high-resolution long-slit H- and K-band spectra of 38 ULIRGs and 12 QSOs (in the range 0.042<z<0.268). In this…

2006 The Astrophysical Journal
eHST 150
The Time Delays of Gravitational Lens HE 0435-1223: An Early-Type Galaxy with a Rising Rotation Curve
DOI: 10.1086/499766 Bibcode: 2006ApJ...640...47K

Kochanek, C. S.; Winn, J. N.; Falco, E. E. +4 more

We present Hubble Space Telescope images and 2 years of optical photometry of the quadruple quasar HE 0435-1223. The time delays between the intrinsic quasar variations are ΔtAD=-14.37+0.75-0.85, ΔtAB=-8.00+0.73-0.82, and ΔtAC=-2.10+0.78-0.71 days. W…

2006 The Astrophysical Journal
eHST 149
First detection of Lyman continuum escape from a local starburst galaxy. I. Observations of the luminous blue compact galaxy Haro 11 with the Far Ultraviolet Spectroscopic Explorer (FUSE)
DOI: 10.1051/0004-6361:20053788 Bibcode: 2006A&A...448..513B

Östlin, G.; Zackrisson, E.; Bergvall, N. +3 more

Context: .The dominating reionization source in the young universe has not yet been identified. Possible candidates include metal poor dwarf galaxies with starburst properties.Aims.We selected an extreme starburst dwarf, the Blue Compact Galaxy Haro 11, with the aim of determining the Lyman continuum escape fraction from UV spectroscopy.Methods.Sp…

2006 Astronomy and Astrophysics
IUE 149