Search Publications
A More Fundamental Plane
Treu, Tommaso; Koopmans, Léon V. E.; Bolton, Adam S. +2 more
We combine strong-lensing masses with SDSS stellar velocity dispersions and HST ACS effective (half-light) radii for 36 lens galaxies from the Sloan Lens ACS (SLACS) Survey to study the mass dependence of mass-dynamical structure in early-type galaxies. We find that over a 180-390 km s-1 range in velocity dispersion, structure is indepe…
Old and Young Bulges in Late-Type Disk Galaxies
Carollo, C. M.; Scarlata, C.; Stiavelli, M. +2 more
We use HST ACS and NICMOS imaging to study the inner B-I and I-H colors of nine late-type spiral galaxies, which we interpret on the basis of different star formation histories. The colors and scale lengths of the bulges of these late-type systems are correlated with those of the disks in which they are embedded. We find that in about half of the …
Cosmic shear analysis of archival HST/ACS data. I. Comparison of early ACS pure parallel data to the HST/GEMS survey
Simon, P.; Heymans, C.; Schrabback, T. +9 more
Context: This is the first paper of a series describing our measurement of weak lensing by large-scale structure, also termed “cosmic shear”, using archival observations from the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST).
Aims: In this work we present results from a pilot study testing the capabilities of the …
Hydration state of the Martian surface as seen by Mars Express OMEGA: 2. H2O content of the surface
Mustard, John F.; Bibring, Jean-Pierre; Langevin, Yves +4 more
Visible-near infrared reflectance spectra acquired by the Mars Express Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA) spectrometer are used to estimate the absolute water content within the uppermost fraction of the Martian regolith. This upper surface layer represents the boundary between the regolith and atmosphere; th…
Can High Frequency Acoustic Waves Heat the Quiet Sun Chromosphere?
Carlsson, Mats; Tsuneta, Saku; Shimizu, Toshifumi +9 more
We use Hinode/SOT Ca II H-line and blue continuum broadband observations to study the presence and power of high frequency acoustic waves at high spatial resolution. We find that there is no dominant power at small spatial scales; the integrated power using the full resolution of Hinode (0.05'' pixels, 0.16'' resolution) is larger than the power i…
On the Formation of Filament Channels
Wang, Y. -M.; Muglach, K.
From the Hα archive of the Big Bear Solar Observatory (BBSO) we have selected three examples showing fibril structures that change their orientation, over 1 or 2 days, from nearly perpendicular to nearly parallel to the polarity inversion line (PIL). In one case, the filament channel forms within a single decaying bipole; in the other two cases, i…
Search for the light dark matter with an X-ray spectrometer
Neronov, A.; Boyarsky, A.; Ruchayskiy, O. +1 more
Sterile neutrinos with the mass in the keV range are interesting warm dark matter (WDM) candidates. The restrictions on their parameters (mass and mixing angle) obtained by current X-ray missions ( XMM-Newton or Chandra) can only be improved by less than an order of magnitude in the near future. Therefore the new strategy of search is needed. We c…
The Black Hole Mass of NGC 4151: Comparison of Reverberation Mapping and Stellar Dynamical Measurements
Peterson, Bradley M.; Heckman, Timothy M.; Pogge, Richard W. +11 more
We present a stellar dynamical estimate of the black hole (BH) mass in the Seyfert 1 galaxy, NGC 4151. We analyze ground-based spectroscopy as well as imaging data from the ground and space, and we construct three-integral axisymmetric models in order to constrain the BH mass and mass-to-light ratio. The dynamical models depend on the assumed incl…
Structure and Dynamics of the Sun's Open Magnetic Field
Antiochos, S. K.; Mikić, Z.; DeVore, C. R. +1 more
The solar magnetic field is the primary agent that drives solar activity and couples the Sun to the heliosphere. Although the details of this coupling depend on the quantitative properties of the field, many important aspects of the corona-solar wind connection can be understood by considering only the general topological properties of those regio…
Characteristics of Titan's stratospheric aerosols and condensate clouds from Cassini CIRS far-infrared spectra
Fletcher, L.; Irwin, P. G. J.; Teanby, N. A. +8 more
Four broad spectral features were identified in far-infrared limb spectra from the Cassini Composite Infrared Spectrometer (CIRS), two of which have not been identified before. The features are broader than the spectral resolution, which suggests that they are caused by particulates in Titan's stratosphere. We derive here the spectral properties a…