Search Publications
The Age of the Young Bulge-like Population in the Stellar System Terzan 5: Linking the Galactic Bulge to the High-z Universe
Dalessandro, E.; Massari, D.; Rich, R. M. +4 more
The Galactic bulge is dominated by an old, metal-rich stellar population. The possible presence and the amount of a young (a few gigayears old) minor component is one of the major issues debated in the literature. Recently, the bulge stellar system Terzan 5 was found to harbor three sub-populations with iron content varying by more than one order …
The Distance to M51
Dolphin, Andrew E.; Skillman, Evan D.; Berg, Danielle +2 more
Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies ha…
BAHAMAS: New Analysis of Type Ia Supernovae Reveals Inconsistencies with Standard Cosmology
van Dyk, David A.; Shariff, Hikmatali; Jiao, Xiyun +1 more
We present results obtained by applying our BAyesian HierArchical Modeling for the Analysis of Supernova cosmology (BAHAMAS) software package to the 740 spectroscopically confirmed supernovae of type Ia (SNe Ia) from the “Joint Light-curve Analysis” (JLA) data set. We simultaneously determine cosmological parameters and standardization parameters,…
An Iron K Component to the Ultrafast Outflow in NGC 1313 X-1
Harrison, F. A.; Stern, D.; Fabian, A. C. +8 more
We present the detection of an absorption feature at E={8.77}-0.06+0.05 keV in the combined X-ray spectrum of the ultraluminous X-ray source NGC 1313 X-1 observed with XMM-Newton and NuSTAR, significant at the 3σ level. If associated with blueshifted ionized iron, the implied outflow velocity is ∼0.2c for Fe xxvi, or ∼0.25c f…
The MOSDEF Survey: Dynamical and Baryonic Masses and Kinematic Structures of Star-forming Galaxies at 1.4 ≤ z ≤ 2.6
Barro, Guillermo; Siana, Brian; Shapley, Alice E. +11 more
We present {{H}}α gas kinematics for 178 star-forming galaxies at z∼ 2 from the MOSFIRE Deep Evolution Field survey. We have developed models to interpret the kinematic measurements from fixed-angle multi-object spectroscopy, using structural parameters derived from Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey Hubble Space Telesc…
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…