Search Publications
Characteristics and variability of Titan's magnetic environment
Bertucci, César L.
The Gemini/HST Cluster Project: Structural and Photometric Properties of Galaxies in Three z = 0.28-0.89 Clusters
Jørgensen, Inger; Chiboucas, Kristin; Barr, Jordi +3 more
We present the data processing and analysis techniques we are using to determine the structural and photometric properties of galaxies in our Gemini/HST Galaxy Cluster Project sample. The goal of this study is to understand cluster galaxy evolution in terms of scaling relations and structural properties of cluster galaxies at redshifts 0.15 < z…
A survey for post-common-envelope binary stars using GALEX and SDSS photometry
Gänsicke, B. T.; Marsh, T. R.; Maxted, P. F. L. +5 more
We report the first results of our programme to obtain multi-epoch radial velocity measurements of stars with a strong far-ultraviolet excess to identify post-common-envelope binaries (PCEBs). The targets have been identified using optical photometry from Sloan Digital Sky Survey (SDSS) DR4, ultraviolet photometry from Galaxy Evolution Explorer (G…
Further Definition of the Mass-Metallicity Relation in Globular Cluster Systems Around Brightest Cluster Galaxies
Whitmore, Bradley C.; Rothberg, Barry; Harris, William E. +2 more
We combine the globular cluster (GC) data for 15 brightest cluster galaxies and use this material to trace the mass-metallicity relations (MMRs) in their globular cluster systems (GCSs). This work extends previous studies which correlate the properties of the MMR with those of the host galaxy. Our combined data sets show a mean trend for the metal…
The structure of an earthward propagating magnetic flux rope early in its evolution: comparison of methods
Möstl, C.; Farrugia, C. J.; Khotyaintsev, Y. +4 more
We analyze a magnetic signature associated with the leading edge of a bursty bulk flow observed by Cluster at -19 RE downtail on 22 August 2001. A distinct rotation of the magnetic field was seen by all four spacecraft. This event was previously examined by Slavin et al. (2003b) using both linear force-free modeling as well as a curlome…
Current filaments in turbulent magnetized plasmas
Sundkvist, D.; Martines, E.; Vianello, N. +18 more
Direct measurements of current density perturbations associated with non-linear phenomena in magnetized plasmas can be carried out using in situ magnetic measurements. In this paper we report such measurements for three different kinds of phenomena. Current density fluctuations in the edge density gradient region of a fusion plasma confined in rev…
A Crossed Molecular Beams Study on the Formation of the Exotic Cyanoethynyl Radical in Titan's Atmosphere
Yung, Y. L.; Gu, X.; Kaiser, R. I. +5 more
The reaction of the dicarbon molecule (C2) in its 1Σg + electronic ground state with hydrogen cyanide HCN(X1Σ+) is investigated in a crossed molecular beam setup to untangle the formation of the cyanoethynyl radical CCCN(X2Σ+) in hydrocarbon-rich atmospheres of…
Spectropolarimetery of umbral fine structures from Hinode: evidence for magnetoconvection
Jain, Rajmal; Bharti, Lokesh; Joshi, Chandan +1 more
We present spectropolarimetric analysis of umbral dots and a light bridge fragment that show dark lanes in G-band images. Umbral dots show upflow as well as associated positive Stokes V area asymmetry in their central parts. Larger umbral dots show downflow patches in their surrounding parts that are associated with negative Stokes V area asymmetr…
Hubble Space Telescope STIS Spectroscopy of the Peculiar Nova-Like Variables BK Lyn, V751 Cygni, and V380 Oph
Sion, Edward M.; Godon, Patrick; Gänsicke, Boris T. +4 more
We obtained Hubble STIS spectra of three nova-like variables: V751 Cygni, V380 Oph, and—the only confirmed nova-like variable known to be below the period gap—BK Lyn. In all three systems, the spectra were taken during high optical brightness state, and a luminous accretion disk dominates their far-ultraviolet (FUV) light. We assessed a lower limi…
The Spectral Types of White Dwarfs in Messier 4
Rich, R. Michael; Richer, Harvey B.; Kalirai, Jason S. +2 more
We present the spectra of 24 white dwarfs in the direction of the globular cluster Messier 4 obtained with the Keck/LRIS and Gemini/GMOS spectrographs. Determining the spectral types of the stars in this sample, we find 24 type DA and 0 type DB (i.e., atmospheres dominated by hydrogen and helium, respectively). Assuming the ratio of DA/DB observed…