Search Publications
HeCS-SZ: The Hectospec Survey of Sunyaev-Zeldovich-selected Clusters
Diaferio, Antonaldo; Hwang, Ho Seong; Geller, Margaret J. +1 more
We estimate cluster masses and velocity dispersions for 123 clusters from optical spectroscopy to compare the Sunyaev-Zeldovich (SZ) mass proxy and dynamical masses. Our new survey, HeCS-SZ (Hectospec Cluster Survey of SZ-selected clusters), includes 7721 new or remeasured redshifts from MMT/Hectospec observations of 21 SZ-selected clusters at red…
The 31 Deg2 Release of the Stripe 82 X-Ray Survey: The Point Source Catalog
Schawinski, Kevin; Comastri, Andrea; Komossa, S. +23 more
We release the next installment of the Stripe 82 X-ray survey point-source catalog, which currently covers 31.3 deg2 of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6181 unique X-ray sources are significantly detected with XMM-Newton (>5σ) and Chandra (>4.5σ). This catalog release includes data from XMM-Ne…
The Diverse Origins of Neutron-capture Elements in the Metal-poor Star HD 94028: Possible Detection of Products of I-Process Nucleosynthesis
Roederer, Ian U.; Karakas, Amanda I.; Pignatari, Marco +1 more
We present a detailed analysis of the composition and nucleosynthetic origins of the heavy elements in the metal-poor ([Fe/H] = -1.62 ± 0.09) star HD 94028. Previous studies revealed that this star is mildly enhanced in elements produced by the slow neutron-capture process (s process; e.g., [Pb/Fe] = +0.79 ± 0.32) and rapid neutron-capture process…
Semi-empirical Modeling of the Photosphere, Chromosphere, Transition Region, and Corona of the M-dwarf Host Star GJ 832
France, Kevin; Fontenla, J. M.; Walkowicz, Lucianne M. +5 more
Stellar radiation from X-rays to the visible provides the energy that controls the photochemistry and mass loss from exoplanet atmospheres. The important extreme ultraviolet (EUV) region (10-91.2 nm) is inaccessible and should be computed from a reliable stellar model. It is essential to understand the formation regions and physical processes resp…
Star Formation Black Hole Growth and Dusty Tori in the Most Luminous AGNs at z=2-3.5
Lani, Caterina; Trakhtenbrot, Benny; Netzer, Hagai +3 more
We report Herschel/SPIRE observations of 100 very luminous, optically selected active galactic nuclei (AGNs) at z=2{--}3.5 with {log} {L}{{1350}} (erg s-1) ≥ 46.5 , where {L}{{1350}} is λLλ at 1350 Å. The distribution in {L}{{1350}} is similar to the general distribution of Sloan Digital Sky S…
The Complex Structure of Magnetic Field Discontinuities in the Turbulent Solar Wind
Perri, S.; Veltri, P.; Yordanova, E. +2 more
Using high-resolution Cluster satellite observations and a multi-dimensional intermittency technique, we show that the magnetic discontinuities in the turbulent solar wind are connected through the spatial scales, going from proton down to electron scales. In some circumstances, their structure resembles the Harris equilibrium profile in plasmas. …
Solar Cycle 25: Another Moderate Cycle?
Schüssler, M.; Jiang, J.; Cameron, R. H.
Surface flux transport simulations for the descending phase of Cycle 24 using random sources (emerging bipolar magnetic regions) with empirically determined scatter of their properties provide a prediction of the axial dipole moment during the upcoming activity minimum together with a realistic uncertainty range. The expectation value for the dipo…
Cold Milky Way HI Gas in Filaments
Kerp, J.; Winkel, B.; Lenz, D. +4 more
We investigate data from the Galactic Effelsberg-Bonn H I Survey, supplemented with data from the third release of the Galactic All Sky Survey (GASS III) observed at Parkes. We explore the all-sky distribution of the local Galactic H I gas with | {v}{{LSR}}| \lt 25 km s-1 on angular scales of 11‧-16‧. Unsharp masking is appli…
Hooked Flare Ribbons and Flux-rope-related QSL Footprints
Li, Hui; Aulanier, Guillaume; Schmieder, Brigitte +3 more
We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory/Atmospheric Imaging Assem…
First Images of Debris Disks around TWA 7, TWA 25, HD 35650, and HD 377
Stark, Christopher C.; Schneider, Glenn; Chen, Christine H. +15 more
We present the first images of four debris disks observed in scattered light around the young (4-250 Myr old) M dwarfs TWA 7 and TWA 25, the K6 star HD 35650, and the G2 star HD 377. We obtained these images by reprocessing archival Hubble Space Telescope NICMOS coronagraph data with modern post-processing techniques as part of the Archival Legacy…