Search Publications
The Observational and Theoretical Tidal Radii of Globular Clusters in M87
Sills, Alison; Harris, William E.; Webb, Jeremy J.
Globular clusters have linear sizes (tidal radii) which theory tells us are determined by their masses and by the gravitational potential of their host galaxy. To explore the relationship between observed and expected radii, we utilize the globular cluster population of the Virgo giant M87. Unusually deep, high signal-to-noise images of M87 are us…
Herschel PACS and SPIRE observations of TW Hydrae association brown dwarf disks
Riaz, B.; Gizis, J. E.
We present Herschel SPIRE observations of the TW Hydrae association (TWA) brown dwarf disks SSSPM J1102-3431 (SS1102) and 2MASSW J1207334-393254 (2M1207). Both disks are undetected in the SPIRE 200-500 µm bands. We analyzed the archival PACS data and found no detection of either source in the 160 µm band. On the basis of radiative tran…
13CO and C18O J = 2-1 mapping of the environment of the Class 0 protostellar core SMM 3 in Orion B9
Miettinen, O.
Context. Observations of molecular spectral lines provide information on the gas kinematics and chemistry of star-forming regions.
Aims: We attempt to achieve a better understanding of the gas distribution and velocity field around the deeply embedded Class 0 protostar SMM 3 in the Orion B9 star-forming region.
Methods: Using the APEX 12…
The ballistic transport instability in Saturn's rings - I. Formalism and linear theory
Ogilvie, Gordon I.; Latter, Henrik N.; Chupeau, Marie
Planetary rings sustain a continual bombardment of hypervelocity meteoroids that erode the surfaces of ring particles on time-scales of 105-107 years. The debris ejected from such impacts re-accretes on to the ring, though often at a slightly different orbital radius from the point of emission. This 'ballistic transport' lead…
Cluster observations of the dusk flank magnetopause near the sash: Ion dynamics and flow-through reconnection
Dunlop, Malcolm; Farrugia, Charles J.; Rème, Henri +5 more
Compared to the dayside, dynamics on the flanks of the magnetopause are poorly understood. To help bridge this knowledge gap we analyzed Cluster plasma and field measurements acquired during a 90-min period on 20 November 2003 when Cluster crossed the magnetopause four times in the vicinity of the sash. MHD simulations provide a context for Cluste…
Constraints on fast ejecta in the Crab supernova remnant from optical spectral lines
Lundqvist, P.; Tziamtzis, A.
The low kinetic energy and mass of the Crab supernova remnant challenge our understanding of core-collapse supernova explosions. A possibility is that the Crab nebula is surrounded by a shell of fast ejecta containing the ‘missing’ kinetic energy and mass. The only direct evidence for such a fast shell comes from an absorption feature in the Crab …
Modeling of electron fluxes in the Enceladus plume
Coates, A. J.; Jones, G. H.; Cravens, T. E. +2 more
Observations by instruments onboard the Cassini spacecraft of Saturn's icy satellite Enceladus have shown that a plume containing water vapor and ice grains is present in the southern hemisphere. Energy distributions of electrons in this plume were measured by the electron sensor part of the Cassini plasma spectrometer (CAPS - ELS). A significant …
Chandra Observations and Classification of Active Galactic Nucleus Candidates Correlated with Auger UHECRs
Zaw, Ingyin; Terrano, William A.; Farrar, Glennys R.
We report on Chandra X-ray observations of possible active galactic nuclei (AGNs) which have been correlated with ultrahigh energy cosmic rays (UHECRs) observed by the Pierre Auger Collaboration. Combining our X-ray observations with optical observations, we conclude that one-third of the 21 Veron-Cetty Veron (VCV) galaxies correlating with UHECRs…
Tidal dwarf galaxies at intermediate redshifts
Gao, Yu; Zheng, Xian-Zhong; Zhao, Ying-He +1 more
We present the first attempt at measuring the production rate of tidal dwarf galaxies (TDGs) and estimating their contribution to the overall dwarf population. Using HST/ACS deep imaging data from GOODS and GEMS surveys in conjunction with photometric redshifts from COMBO-17 survey, we performed a morphological analysis for a sample of merging/int…
Solar Intranetwork Magnetic Elements: Intrinsically Weak or Strong?
Wang, J. X.; Xie, Z. X.; Jin, C. L.
The high spatial resolution observation of a quiet region taken with the Solar Optical Telescope/Spectro-Polarimeter aboard the Hinode spacecraft is analyzed. Based on the Milne-Eddington atmospheric model, the vector magnetic field of the quiet region is derived by fitting the full Stokes profiles of the Fe I 630 nm line pair. We extract intranet…