Search Publications
Dynamical Evolution of AGN Host Galaxies—Gas In/Out-Flow Rates in Seven NUGA Galaxies
Schinnerer, Eva; Emsellem, Eric; Rix, Hans-Walter +4 more
To examine the role of the host galaxy structure in fueling nuclear activity, we estimated gas flow rates from several kpc down to the inner few 10 pc for seven nearby spiral galaxies, selected from the NUclei of GAlaxies sample. We calculated gravitational torques from near-infrared images and determined gas in/out-flow rates as a function of rad…
Exo-Dat: An Information System in Support of the CoRoT/Exoplanet Science
Guterman, P.; Barbieri, M.; Deleuil, M. +9 more
Exo-Dat is a database and an information system created primarily in support of the exoplanet program of the COnvection ROtation & planetary Transits (CoRoT) mission. In the directions of CoRoT pointings, it provides a united interface to several sets of data: stellar published catalogs, photometric and spectroscopic data obtained during the m…
Upward propagating high-frequency Alfvén waves as identified from dynamic wave-like spicules observed by SOT on Hinode
Tu, C. -Y.; Marsch, E.; Tian, H. +3 more
Aims: We identify high-frequency Alfvén waves propagating upward in the solar chromosphere and transition region from observation by Solar Optical Telescope (SOT) onboard Hinode.
Methods: The spicule shape is enhanced through application of a normal radial gradient filter and an un-sharp mask on the images taken by SOT. The displaced position …
Numerical Experiments of Wave-like Phenomena Caused by the Disruption of an Unstable Magnetic Configuration
Lin, Jun; Shen, Chengcai; Wang, Hongjuan
The origin of the Moreton wave observed in the chromosphere and the EIT wave observed in the corona during the eruption remains an active research subject. We investigate numerically in this work the evolutionary features of the magnetic configuration that includes a current-carrying flux rope, which is used to model the filament, after the loss o…
Cepheid Calibrations of Modern Type Ia Supernovae: Implications for the Hubble Constant
Ferguson, Henry C.; Casertano, Stefano; Mutchler, Max +10 more
This is the first of two papers reporting measurements from a program to determine the Hubble constant to ~5% precision from a refurbished distance ladder. We present new observations of 110 Cepheid variables in the host galaxies of two recent Type Ia supernovae (SNe Ia), NGC 1309 and NGC 3021, using the Advanced Camera for Surveys on the Hubble S…
Dissecting the Gravitational Lens B1608+656. I. Lens Potential Reconstruction
McKean, J. P.; Treu, T.; Blandford, R. D. +4 more
Strong gravitational lensing is a powerful technique for probing galaxy mass distributions and for measuring cosmological parameters. Lens systems with extended source-intensity distributions are particularly useful for this purpose since they provide additional constraints on the lens potential (mass distribution). We present a pixelated approach…
The first outburst of the new magnetar candidate SGR0501+4516
Campana, S.; Tiengo, A.; Hurley, K. +17 more
We report here on the outburst onset and evolution of the new soft gamma-ray repeater SGR0501+4516. We monitored the new SGR with XMM-Newton starting on 2008 August 23, 1 day after the source became burst active, and continuing with four more observations in the following month, with the last one on 2008 September 30. Combining the data with the S…
New Tests for Disruption Mechanisms of Star Clusters: Methods and Application to the Antennae Galaxies
Whitmore, Bradley C.; Fall, S. Michael; Chandar, Rupali
We present new tests for disruption mechanisms of star clusters based on the bivariate mass-age distribution g(M, τ). In particular, we derive formulae for g(M, τ) for two idealized models in which the rate of disruption depends on the masses of the clusters and one in which it does not. We then compare these models with our Hubble Space Telescope…
Black hole growth and starburst activity at z = 0.6-4 in the Chandra Deep Field South. Host galaxies properties of obscured AGN
Merloni, A.; Fiore, F.; Comastri, A. +8 more
Aims: The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured active galactic nuclei (AGN) detected in the CDFS 1 Ms observation and their host galaxies.
Methods: We limited the analysis…
New Limits on Sterile Neutrinos from Suzaku Observations of the Ursa Minor Dwarf Spheroidal Galaxy
Loewenstein, Michael; Biermann, Peter L.; Kusenko, Alexander
We present results of our search for X-ray line emission associated with the radiative decay of the sterile neutrino, a well motivated dark matter candidate, in Suzaku Observatory spectra of the Ursa Minor dwarf spheroidal galaxy. These data represent the first deep observation of one of these extreme mass-to-light systems and the first dedicated …