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Globular Cluster Systems in Brightest Cluster Galaxies: Bimodal Metallicity Distributions and the Nature of the High-Luminosity Clusters
Whitmore, Bradley C.; Kavelaars, J. J.; Baum, William A. +4 more
We present new (B, I) photometry for the globular cluster systems in eight brightest cluster galaxies (BCGs), obtained with the ACS/WFC camera on the Hubble Space Telescope. In the very rich cluster systems that reside within these giant galaxies, we find that all have strongly bimodal color distributions that are clearly resolved by the metallici…
Near-Infrared and Star-forming Properties of Local Luminous Infrared Galaxies
Pérez-González, Pablo G.; Ryder, Stuart D.; Colina, Luis +3 more
We use Hubble Space Telescope (HST) NICMOS continuum and Paα observations to study the near-infrared and star formation properties of a representative sample of 30 local (d~35-75 Mpc) luminous infrared galaxies (LIRGs, infrared [8-1000 µm] luminosities of logLIR=11-11.9 Lsolar). The data provide spatial resolutions of 2…
Light neutralino dark matter in the next-to-minimal supersymmetric standard model
Hooper, Dan; Gunion, John F.; McElrath, Bob
Neutralino dark matter is generally assumed to be relatively heavy, with a mass near the electroweak scale. This does not necessarily need to be the case, however. In the next-to-minimal supersymmetric standard model (NMSSM) and other supersymmetric models with an extended Higgs sector, a very light CP-odd Higgs boson can naturally arise making it…
The great observatories origins deep survey. VLT/FORS2 spectroscopy in the GOODS-South Field: Part II
Popesso, P.; Cesarsky, C.; Stern, D. +16 more
Aims.We present the second campaign of the ESO/GOODS program of spectroscopy of faint galaxies in the GOODS-South field.
Methods: .Objects were selected as candidates for VLT/FORS2 observations primarily based on the expectation that the detection and measurement of their spectral features would benefit from the high throughput and spectral re…
Magnetoacoustic Portals and the Basal Heating of the Solar Chromosphere
McIntosh, Scott W.; Cacciani, Alessandro; Armstrong, James D. +3 more
We show that inclined magnetic field lines at the boundaries of large-scale convective cells (supergranules) provide ``portals'' through which low-frequency (<5 mHz) magnetoacoustic waves can propagate into the solar chromosphere. The energy flux carried by these waves at a height of 400 km above the solar surface is found to be a factor of 4 g…
The N2K Consortium. IV. New Temperatures and Metallicities for More than 100,000 FGK Dwarfs
Strader, Jay; Laughlin, Gregory; Ammons, S. Mark +3 more
We have created specialized target lists for radial velocity surveys that are biased toward stars that (1) possess planets and (2) are easiest to observe with current detection techniques. We use a procedure that uniformly estimates fundamental stellar properties of Tycho 2 stars, with errors, using spline functions of broadband photometry and pro…
The link between submillimetre galaxies and luminous ellipticals: near-infrared IFU spectroscopy of submillimetre galaxies
Ivison, R. J.; Smail, Ian; Swinbank, A. M. +5 more
We present two-dimensional spectroscopy covering the rest-frame wavelengths of strong optical emission lines in six luminous submillimetre galaxies (SMGs) at z = 1.3-2.5. Using this near-infrared integral field spectroscopy together with Hubble Space Telescope ACS and NICMOS imaging, we map the dynamics and morphologies of these systems on scales …
The Hard X-Ray Spectral Slope as an Accretion Rate Indicator in Radio-quiet Active Galactic Nuclei
Maiolino, Roberto; Brandt, W. N.; Kaspi, Shai +2 more
We present new XMM-Newton observations of two luminous and high accretion rate radio-quiet active galactic nuclei (AGNs) at z~2. Together with archival X-ray and rest-frame optical spectra of three sources with similar properties, as well as 25 moderate-luminosity radio-quiet AGNs at z<0.5, we investigate, for the first time, the dependence of …
Hubble Space Telescope STIS Spectra of Nuclear Star Clusters in Spiral Galaxies: Dependence of Age and Mass on Hubble Type
Böker, Torsten; Ho, Luis C.; Shields, Joseph C. +5 more
We study the nuclear star clusters (NCs) in spiral galaxies of various Hubble types using spectra obtained with the STIS on board the Hubble Space Telescope (HST). We observed the nuclear clusters in 40 galaxies, selected from two previous HST WFPC2 imaging surveys. At a spatial resolution of ~0.2" the spectra provide a better separation of cluste…
The Proper Treatment of Coronal Mass Ejection Brightness: A New Methodology and Implications for Observations
Vourlidas, Angelos; Howard, Russell A.
With the complement of coronagraphs and imagers in the SECCHI suite, we will follow a coronal mass ejection (CME) continuously from the Sun to Earth for the first time. The comparison, however, of the CME emission among the various instruments is not as easy as one might think. This is because the telescopes record the Thomson-scattered emission f…