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Observations of Thick Disks in the Hubble Space Telescope Ultra Deep Field
Elmegreen, Bruce G.; Elmegreen, Debra Meloy
The vertical profiles of chain and spiral galaxies in the Hubble Space Telescope Ultra Deep Field (UDF) are fit to sech2(z/z0) functions convolved with stellar profiles in order to measure the disk scale heights z0 in four passbands. The bulge regions of the spiral galaxies are avoided. Photometric redshifts give a…
Coronal Holes, Jets, and the Origin of 3He-rich Particle Events
Pick, M.; Mason, G. M.; Wang, Y. -M.
Using magnetograph measurements, coronal field extrapolations, and imaging observations, we investigate the solar origins of 25 3He-rich particle events from the period 1997-2003. In essentially every case we find that the source of the impulsive solar energetic particles (SEPs) lies next to a coronal hole containing Earth-directed open…
Minkowski's Object: A Starburst Triggered by a Radio Jet, Revisited
Stanford, S. A.; Morganti, Raffaella; Oosterloo, Tom +8 more
We present neutral hydrogen, ultraviolet, optical, and near-infrared imaging, and optical spectroscopy, of Minkowski's Object (MO), a star-forming peculiar galaxy near NGC 541. The observations strengthen evidence that star formation in MO was triggered by the radio jet from NGC 541. Key new results are the discovery of a 4.9×108 M…
Exploring Brown Dwarf Disks: A 1.3 mm Survey in Taurus
Wood, Kenneth; Jayawardhana, Ray; Scholz, Alexander
We have carried out sensitive 1.3 mm observations of 20 young brown dwarfs in the Taurus star-forming region, representing the largest sample of young substellar objects targeted in a deep millimeter-continuum survey to date. Under standard assumptions, the masses of brown dwarf disks range from <~0.4 to several Jupiter masses. Their relative d…
Spitzer IRAC Confirmation of z850-Dropout Galaxies in the Hubble Ultra Deep Field: Stellar Masses and Ages at z ~ 7
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…
Discovery of an Extraordinarily Massive Cluster of Red Supergiants
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…
The Morphological Diversities among Star-forming Galaxies at High Redshifts in the Great Observatories Origins Deep Survey
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…
The Calm before the Storm: The Link between Quiescent Cavities and Coronal Mass Ejections
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 …
Dynamical Properties of Ultraluminous Infrared Galaxies. I. Mass Ratio Conditions for ULIRG Activity in Interacting Pairs
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…
The Time Delays of Gravitational Lens HE 0435-1223: An Early-Type Galaxy with a Rising Rotation Curve
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…