Search Publications
Fomalhaut's Debris Disk and Planet: Constraining the Mass of Fomalhaut b from disk Morphology
Clampin, M.; Kite, E.; Kalas, P. +2 more
Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then …
Active Galactic Nucleus Host Galaxy Morphologies in COSMOS
Smolčić, V.; Jahnke, K.; Salvato, M. +14 more
We use Hubble Space Telescope/Advanced Camera for Surveys images and a photometric catalog of the Cosmic Evolution Survey (COSMOS) field to analyze morphologies of the host galaxies of ~400 active galactic nucleus (AGN) candidates at redshifts 0.3 < z < 1.0. We compare the AGN hosts with a sample of nonactive galaxies drawn from the COSMOS f…
GRB 080503: Implications of a Naked Short Gamma-Ray Burst Dominated by Extended Emission
Butler, N. R.; Sakamoto, T.; Bloom, J. S. +22 more
We report on observations of GRB 080503, a short gamma-ray burst (GRB) with very bright extended emission (about 30 times the gamma-ray fluence of the initial spike) in conjunction with a thorough comparison to other short Swift events. In spite of the prompt-emission brightness, however, the optical counterpart is extraordinarily faint, never exc…
Detections of Lyman Continuum from Star-Forming Galaxies at z ~ 3 through Subaru/Suprime-Cam Narrow-Band Imaging
Burgarella, D.; Furusawa, H.; Yamada, T. +7 more
Knowing the amount of ionizing photons from young star-forming galaxies is of particular importance to understanding the reionization process. Here we report initial results of a Subaru/Suprime-Cam deep imaging observation of the SSA22 proto-cluster region at z = 3.09, using a special narrow-band filter to optimally trace ionizing radiation from g…
Empirical Constraints on Proton and Electron Heating in the Fast Solar Wind
Cranmer, Steven R.; Kasper, Justin C.; Matthaeus, William H. +1 more
We analyze measured proton and electron temperatures in the high-speed solar wind in order to calculate the separate rates of heat deposition for protons and electrons. When comparing with other regions of the heliosphere, the fast solar wind has the lowest density and the least frequent Coulomb collisions. This makes the fast wind an optimal test…
Velocity Characteristics of Evaporated Plasma Using Hinode/EUV Imaging Spectrometer
Milligan, Ryan O.; Dennis, Brian R.
This paper presents a detailed study of chromospheric evaporation using the EUV Imaging Spectrometer (EIS) onboard Hinode in conjunction with hard X-ray (HXR) observations from Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). The advanced capabilities of EIS were used to measure Doppler shifts in 15 emission lines covering the temper…
The Spatially Resolved Star Formation Law From Integral Field Spectroscopy: VIRUS-P Observations of NGC 5194
Blanc, Guillermo A.; Gebhardt, Karl; Evans, Neal J., II +2 more
We investigate the relation between the star formation rate (SFR) surface density (ΣSFR) and the mass surface density of gas (Σgas) in NGC 5194 (a.k.a. M51a, Whirlpool Galaxy). Visible Integral field Replicable Unit Spectrograph Prototype (VIRUS-P) integral field spectroscopy of the central 4.1 × 4.1 kpc2 of the ga…
On the Weakening of the Polar Magnetic Fields during Solar Cycle 23
Sheeley, N. R., Jr.; Wang, Y. -M.; Robbrecht, E.
The Sun's polar fields are currently ~40% weaker than they were during the previous three sunspot minima. This weakening has been accompanied by a corresponding decrease in the interplanetary magnetic field (IMF) strength, by a ~20% shrinkage in the polar coronal-hole areas, and by a reduction in the solar-wind mass flux over the poles. It has als…
OGLE-2005-BLG-071Lb, the Most Massive M Dwarf Planetary Companion?
Bennett, D. P.; Cook, K. H.; Gal-Yam, A. +85 more
We combine all available information to constrain the nature of OGLE-2005-BLG-071Lb, the second planet discovered by microlensing and the first in a high-magnification event. These include photometric and astrometric measurements from the Hubble Space Telescope, as well as constraints from higher order effects extracted from the ground-based light…
Evolution of the Color-Magnitude Relation in Galaxy Clusters at z ~ 1 from the ACS Intermediate Redshift Cluster Survey
Franx, Marijn; Illingworth, Garth D.; Postman, Marc +10 more
We apply detailed observations of the color-magnitude relation (CMR) with the Advanced Camera for Surveys on the Hubble Space Telescope to study galaxy evolution in eight clusters at z≈ 1. The early-type red sequence is well defined and elliptical and lenticular galaxies lie on similar CMRs. We analyze CMR parameters—scatter, slope, and zero point…