Search Publications
Herschel-ATLAS: the far-infrared-radio correlation at z < 0.5
Rodighiero, G.; Ivison, R. J.; de Zotti, G. +45 more
We use data from the Herschel-ATLAS to investigate the evolution of the far-infrared-radio correlation over the redshift range 0 < z < 0.5. Using the total far-infrared luminosity of all >5σ sources in the Herschel-ATLAS Science Demonstration Field and cross-matching these data with radio data from the Faint Images of the Radio Sky at Twe…
Heliospheric evolution of solar wind small-scale magnetic flux ropes
Moldwin, M. B.; Cartwright, M. L.
We present results from the first comprehensive small-scale flux rope survey between 0.3 and 5.5 AU using the Helios 1, Helios 2, IMP 8, Wind, ACE, and Ulysses spacecrafts to examine their occurrence rate, properties, and evolution. Small-scale flux ropes are similar to magnetic clouds and can be modeled as a constant-alpha, force-free, cylindrica…
The Supermassive Black Hole and Dark Matter Halo of NGC 4649 (M60)
Gebhardt, Karl; Shen, Juntai
We apply the axisymmetric orbit superposition modeling to estimate the mass of the supermassive black hole (BH) and dark matter (DM) halo profile of NGC 4649. We have included data sets from the Hubble Space Telescope (HST), stellar, and globular cluster (GC) observations. Our modeling gives M • = (4.5 ± 1.0) × 109 M sun…
The X-ray to [Ne V]3426 flux ratio: discovering heavily obscured AGN in the distant Universe
Vignali, C.; Gilli, R.; Comastri, A. +3 more
We investigate the possibility of using the ratio between the 2-10 keV flux and the [Ne V]3426 emission line flux (X/NeV) as a diagnostic diagram to discover heavily obscured, possibly Compton-thick active galactic nuclei (AGN) in the distant Universe. While it is on average about one order of magnitude fainter than the more commonly used [O III]5…
The ACS Survey of Galactic Globular Clusters. VIII. Effects of Environment on Globular Cluster Global Mass Functions
Anderson, Jay; Dotter, Aaron; Sarajedini, Ata +12 more
We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic Globular Clusters to construct global present-day mass functions for 17 globular clusters utilizing multi-mass King models to extrapolate from our observations to the global cluster behavior. The global present-day mass functions for these clusters are …
The age of the Medusae Fossae Formation: Evidence of Hesperian emplacement from crater morphology, stratigraphy, and ancient lava contacts
Head, James W.; Kerber, Laura
The Medusae Fossae Formation (MFF), covering about 2.1 × 10 6 km 2 (with an estimated volume of 1.4 × 10 6 km 3) and straddling the equatorial region of Mars east of Tharsis, has historically been mapped and dated as Amazonian in age. Analysis of the MFF using a range of new observations from recent miss…
Lava tubes and basaltic caves as astrobiological targets on Earth and Mars: A review
Léveillé, Richard J.; Datta, Saugata
Lava tubes and basaltic caves are common features in volcanic terrains on Earth. Lava tubes and cave-like features have also been identified on Mars based on orbital imagery and remote-sensing data. Caves are unique environments where both secondary mineral precipitation and microbial growth are enhanced by stable physico-chemical conditions. Thus…
Surface Brightness Fluctuations in the Hubble Space Telescope ACS/WFC F814W Bandpass and an Update on Galaxy Distances
Jordán, Andrés; Tonry, John L.; Côté, Patrick +7 more
We measure surface brightness fluctuation (SBF) magnitudes in the F814W filter and (g 475 - I 814) colors for nine bright early-type Fornax cluster galaxies imaged with the Hubble Space Telescope Advanced Camera for Surveys (ACS). The goal is to achieve the first systematic SBF calibration for the ACS/F814W bandpass. Because …
SN 2007od: A Type IIP Supernova with Circumstellar Interaction
Welch, D. L.; Gallagher, J. S.; Barlow, M. J. +9 more
SN 2007od exhibits characteristics that have rarely been seen in a Type IIP supernova (SN). Optical V-band photometry reveals a very steep brightness decline between the plateau and nebular phases of ~4.5 mag, likely due to SN 2007od containing a low mass of 56Ni. The optical spectra show an evolution from normal Type IIP with broad Hα …
The radio properties of a complete, X-ray selected sample of nearby, massive elliptical galaxies
Fabian, A. C.; Reynolds, C. S.; Gentile, G. +4 more
We investigate the radio properties of a complete sample of nearby, massive, X-ray bright elliptical and S0 galaxies. Our sample contains 18 galaxies with ROSAT All-Sky Survey X-ray fluxes FX,0.1-2.4keV > 3 × 10-12ergs-1cm-2, within a distance of 100Mpc. For these galaxies, we have completed (18/18) V…