Search Publications
The First Measurement of the Adiabatic Index in the Solar Corona Using Time-dependent Spectroscopy of Hinode/EIS Observations
Del Zanna, Giulio; Van Doorsselaere, Tom; Nakariakov, Valery M. +3 more
We use observations of a slow magnetohydrodynamic wave in the corona to determine for the first time the value of the effective adiabatic index, using data from the Extreme-ultraviolet Imaging Spectrometer on board Hinode. We detect oscillations in the electron density, using the CHIANTI atomic database to perform spectroscopy. From the time-depen…
Galaxy stellar mass functions of different morphological types in clusters, and their evolution between z= 0.8 and 0
Cava, Antonio; Fritz, Jacopo; Dressler, Alan +11 more
We present the galaxy stellar mass function and its evolution in clusters from z∼ 0.8 to the current epoch, based on the WIde-field Nearby Galaxy-cluster Survey (WINGS) (0.04 ≤z≤ 0.07), and the ESO Distant Cluster Survey (EDisCS) (0.4 ≤z≤ 0.8). We investigate the total mass function and find that it evolves noticeably with redshift. The shape at M…
Measuring moonlight: An overview of the spatial properties, lunar coverage, selenolocation, and related Level 1B products of the Moon Mineralogy Mapper
Besse, S.; Isaacson, P.; Pieters, C. M. +7 more
The Moon Mineralogy Mapper (M3), a high-resolution, high-precision imaging spectrometer, flew on board India's Chandrayaan-1 Mission from October 2008 through August 2009. This paper describes some of the spatial sampling aspects of the instrument, the planned mission, and the mission as flown. We also outline the content and context of…
Two Components of the Solar Coronal Emission Revealed by Extreme-ultraviolet Spectroscopic Observations
Martínez-Sykora, Juan; De Pontieu, Bart; Wang, Xin +3 more
Recent spectroscopic observations have revealed the ubiquitous presence of blueward asymmetries of emission lines formed in the solar corona and transition region. These asymmetries are most prominent in loop footpoint regions, where a clear correlation of the asymmetry with the Doppler shift and line width determined from the single-Gaussian fit …
The Dark Matter Distribution in A383: Evidence for a Shallow Density Cusp from Improved Lensing, Stellar Kinematic, and X-ray Data
Treu, Tommaso; Ellis, Richard S.; Newman, Andrew B. +1 more
We extend our analyses of the dark matter (DM) distribution in relaxed clusters to the case of A383, a luminous X-ray cluster at z = 0.189 with a dominant central galaxy and numerous strongly lensed features. Following our earlier papers, we combine strong and weak lensing constraints secured with Hubble Space Telescope and Subaru imaging with the…
Constraints on the Heating of High-temperature Active Region Loops: Observations from Hinode and the Solar Dynamics Observatory
Winebarger, Amy R.; Warren, Harry P.; Brooks, David H.
We present observations of high-temperature emission in the core of a solar active region using instruments on Hinode and the Solar Dynamics Observatory (SDO). These multi-instrument observations allow us to determine the distribution of plasma temperatures and follow the evolution of emission at different temperatures. We find that at the apex of…
Emission Lines from the Gas Disk around TW Hydra and the Origin of the Inner Hole
Pascucci, I.; Najita, J.; Hollenbach, D. +1 more
We compare line emission calculated from theoretical disk models with optical to submillimeter wavelength observational data of the gas disk surrounding TW Hya and infer the spatial distribution of mass in the gas disk. The model disk that best matches observations has a gas mass ranging from ~10-4 to 10-5 M sun fo…
UV-to-FIR Analysis of Spitzer/IRAC Sources in the Extended Groth Strip. II. Photometric Redshifts, Stellar Masses, and Star Formation Rates
Yamada, T.; Kajisawa, M.; Ashby, M. L. N. +6 more
Based on the ultraviolet to far-infrared photometry already compiled and presented in a companion paper (Paper I), we present a detailed spectral energy distribution (SED) analysis of nearly 80,000 IRAC 3.6 + 4.5 µm selected galaxies in the Extended Groth Strip. We estimate photometric redshifts, stellar masses, and star formation rates (SFR…
Fe-K Line Probing of Material Around the Active Galactic Nucleus Central Engine with Suzaku
Fukazawa, Yasushi; Ohno, Masanori; Nishino, Sho +6 more
We systematically analyzed the high-quality Suzaku data of 88 Seyfert galaxies, about 31% of which are Compton-thick active galactic nuclei (AGNs). We obtained a clear relation between the absorption column density and the equivalent width (EW) of the 6.4 keV line above 1023 cm-2, suggesting a wide-ranging column density of 1…
Evidence for Cold Accretion: Primitive Gas Flowing onto a Galaxy at z ~ 0.274
Tripp, Todd M.; Prochaska, J. Xavier; Lehner, Nicolas +5 more
We present UV and optical observations from the Cosmic Origins Spectrograph on the Hubble Space Telescope and Keck of a z = 0.27395 Lyman limit system (LLS) seen in absorption against the QSO PG1630+377. We detect H I absorption with log N(H I) = 17.06 ± 0.05 as well as Mg II, C III, Si III, and O VI in this system. The column densities are readil…