Search Publications
Discovery of a Superluminal Fe K Echo at the Galactic Center: The Glorious Past of Sgr A* Preserved by Molecular Clouds
Ponti, G.; Terrier, R.; Goldwurm, A. +2 more
We present the result of a study of the X-ray emission from the galactic center (GC) molecular clouds (MCs) within 15 arcmin from Sgr A*. We use XMM-Newton data (about 1.2 Ms of observation time) spanning about eight years. The MC spectra show all the features characteristic of reflection: (1) intense Fe Kα, with equivalent width of about 0.7-1 ke…
Quiescent Prominence Dynamics Observed with the Hinode Solar Optical Telescope. I. Turbulent Upflow Plumes
Magara, Tetsuya; Shimizu, Toshifumi; Okamoto, Takenori J. +10 more
Hinode/Solar Optical Telescope (SOT) observations reveal two new dynamic modes in quiescent solar prominences: large-scale (20-50 Mm) "arches" or "bubbles" that "inflate" from below into prominences, and smaller-scale (2-6 Mm) dark turbulent upflows. These novel dynamics are related in that they are always dark in visible-light spectral bands, the…
Herschel and SCUBA-2 imaging and spectroscopy of a bright, lensed submillimetre galaxy at z = 2.3
Smail, I.; Valtchanov, I.; Ivison, R. J. +32 more
We present a detailed analysis of the far-infrared (-IR) properties of the bright, lensed, z = 2.3, submillimetre-selected galaxy (SMG), SMM J2135-0102 (hereafter SMM J2135), using new observations with Herschel, SCUBA-2 and the Very Large Array (VLA). These data allow us to constrain the galaxy's spectral energy distribution (SED) and show that i…
Gas-phase Oxygen Gradients in Strongly Interacting Galaxies. I. Early-stage Interactions
Kewley, Lisa J.; Rupke, David S. N.; Chien, L. -H.
A consensus is emerging that interacting galaxies show depressed nuclear gas metallicities compared to isolated star-forming galaxies. Simulations suggest that this nuclear underabundance is caused by interaction-induced inflow of metal-poor gas and that this inflow concurrently flattens the radial metallicity gradients in strongly interacting gal…
AINUR: Atlas of Images of NUclear Rings
Knapen, J. H.; Comerón, S.; Beckman, J. E. +4 more
We present the most complete atlas of nuclear rings to date. We include 113 rings found in 107 galaxies, six of which are elliptical galaxies, five are highly inclined disc galaxies, 18 are unbarred disc galaxies and 78 are barred disc galaxies. Star-forming nuclear rings occur in 20 +/- 2 per cent of disc galaxies with types between T = -3 and T …
Herschel unveils a puzzling uniformity of distant dusty galaxies
Berta, S.; Magnelli, B.; Nordon, R. +106 more
The Herschel Space Observatory enables us to accurately measure the bolometric output of starburst galaxies and active galactic nuclei (AGN) by directly sampling the peak of their far-infrared (IR) emission. Here we examine whether the spectral energy distribution (SED) and dust temperature of galaxies have strongly evolved over the last 80% of th…
Anisotropy of Solar Wind Turbulence between Ion and Electron Scales
Alexandrova, O.; Horbury, T. S.; Chen, C. H. K. +3 more
The anisotropy of turbulence in the fast solar wind, between the ion and electron gyroscales, is directly observed using a multispacecraft analysis technique. Second order structure functions are calculated at different angles to the local magnetic field, for magnetic fluctuations both perpendicular and parallel to the mean field. In both componen…
Absorption-line Probes of the Prevalence and Properties of Outflows in Present-day Star-forming Galaxies
Weiner, Benjamin J.; Brinchmann, Jarle; Heckman, Timothy M. +4 more
We analyze star-forming galaxies drawn from SDSS DR7 to show how the interstellar medium (ISM) Na I λλ5890, 5896 (Na D) absorption lines depend on galaxy physical properties, and to look for evidence of galactic winds. We combine the spectra of galaxies with similar geometry/physical parameters to create composite spectra with signal-to-noise ~300…
LoCuSS: first results from strong-lensing analysis of 20 massive galaxy clusters at z = 0.2
Richard, Johan; Smith, Graham P.; Egami, E. +13 more
We present a statistical analysis of a sample of 20 strong lensing clusters drawn from the Local Cluster Substructure Survey, based on high-resolution Hubble Space Telescope imaging of the cluster cores and follow-up spectroscopic observations using the Keck-I telescope. We use detailed parametrized models of the mass distribution in the cluster c…
Globular cluster systems in nearby dwarf galaxies - III. Formation efficiencies of old globular clusters
Georgiev, Iskren Y.; Goudfrooij, Paul; Puzia, Thomas H. +1 more
We investigate the origin of the shape of the globular cluster (GC) system scaling parameters as a function of galaxy mass, i.e. specific frequency (SN), specific luminosity (SL), specific mass (SM) and specific number () of GCs. In the low-mass galaxy regime (MV >~ -16 mag), our analysis is based on …