Search Publications
Missions
Journals
Publication Years
Progressive Star Formation in the Young SMC Cluster NGC 602
Tosi, M.; Sabbi, E.; Nota, A. +9 more
NGC 602 is a young stellar cluster located in a peripheral region of the Small Magellanic Cloud (SMC) known as the wing. Far from the main body of the galaxy and abutting the Magellanic Bridge, the SMC's wing is characterized by low gas and stellar content. With deep optical imaging from the Advanced Camera for Surveys (ACS) aboard the Hubble Spac…
21 cm Synthesis Observations of VIRGOHI 21-A Possible Dark Galaxy in the Virgo Cluster
Impey, Chris; van Driel, Wim; Davies, Jonathan +10 more
Many observations indicate that dark matter dominates the extragalactic universe, yet no totally dark structure of galactic proportions has ever been convincingly identified. Previously, we have suggested that VIRGOHI 21, a 21 cm source we found in the Virgo Cluster using Jodrell Bank, was a possible dark galaxy because of its broad line width (~2…
Prominence and quiet-Sun plasma parameters derived from FUV spectral emission
Vial, J. -C.; Parenti, S.
Context: A solar prominence and the quiet-Sun (QS) were observed with SOHO/SUMER in October 1999. With this dataset we built the first comprehensive UV spectral atlas in the range 800-1250 Å for a prominence, thus complementing the existing reference atlases for the QS.
Aims: This is a detailed study based on the information in this atlas, wit…
Tethys and Dione as sources of outward-flowing plasma in Saturn's magnetosphere
André, N.; Coates, A. J.; Dougherty, M. K. +4 more
Rotating at over twice the angular speed of Earth, Saturn imposes a rapid spin on its magnetosphere. As a result, cold, dense plasma is believed to be flung outward from the inner magnetosphere by centrifugal force and replaced by hotter, more tenuous plasma from the outer magnetosphere. The centrifugal interchange of plasmas in rotating magnetosp…
Fragmentation Hierarchy of Bright Sungrazing Comets and the Birth and Orbital Evolution of the Kreutz System. II. The Case for Cascading Fragmentation
Sekanina, Zdenek; Chodas, Paul W.
We examine the process of cascading fragmentation for the Kreutz sungrazer system to continue our exploration of its birth, orbital evolution, and temporal clumping. We modify and broaden the two-superfragment model from Paper I to include clusters of ~30 bright comets spanning four centuries and 1000 SOHO sungrazers from 1996 to 2006. The spectac…
A Correlation between Galaxy Morphology and Mg II Halo Absorption Strength
Kacprzak, Glenn G.; Steidel, Charles C.; Churchill, Christopher W. +2 more
We compared the quantified morphological properties of 37 intermediate redshift Mg II absorption selected galaxies to the properties of the absorbing halo gas [0.03 Å<=Wr(2796)<=2.90 Å], observed in the spectra of background quasars. The galaxy morphologies were measured using GIM2D modeling of Hubble Space Telescope WFPC2 images …
The orbit, mass, size, albedo, and density of (65489) Ceto/Phorcys: A tidally-evolved binary Centaur
Spencer, J. R.; Cruikshank, D. P.; Trilling, D. E. +6 more
Hubble Space Telescope observations of Uranus- and Neptune-crossing object (65489) Ceto/Phorcys (provisionally designated 2003 FX 128) reveal it to be a close binary system. The mutual orbit has a period of 9.554±0.011 days and a semimajor axis of 1840±48 km. These values enable computation of a system mass of (5.41±0.42)×10 kg. Spitzer…
Evidence for a z < 8 Origin of the Source-subtracted Near-Infrared Background
Fan, Xiaohui; Kennicutt, Robert C.; Rieke, Marcia +2 more
This paper extends our previous fluctuation analysis of the near-infrared background at 1.6 µm to the 1.1 µm (F110W) image of the Hubble Ultra Deep Field. When all detectable sources are removed, the ratio of fluctuation power in the two images is consistent with the ratio expected for faint, z<8, sources, and is inconsistent with t…
Proper motion dispersions of red clump giants in the galactic bulge: observations and model comparisons
Gerhard, Ortwin; Sumi, Takahiro; Mao, Shude +3 more
Red clump giants (RCGs) in the Galactic bulge are approximate standard candles and hence they can be used as distance indicators. We compute the proper motion dispersions of RCG stars in the Galactic bulge using the proper motion catalogue from the second phase of the Optical Gravitational Microlensing Experiment (OGLE-II) for 45 fields. The prope…
Origin of the X-Ray Quasi-periodic Oscillations and Identification of a Transient Ultraluminous X-Ray Source in M82
Feng, Hua; Kaaret, Philip
The starburst galaxy M82 contains two ultraluminous X-ray sources (ULXs), CXOM82 J095550.2+694047 (=X41.4+60) and CXOM82 J095551.1+694045 (=X42.3+59), which are unresolved by XMM-Newton. We revisited the two XMM-Newton observations of M82 and analyzed the surface brightness profiles using the known Chandra source positions. We show that the quasi-…