Search Publications
A Model of the Hα and Na Transmission Spectrum of HD 189733b
Arras, Phil; Li, Zhi-Yun; Christie, Duncan +1 more
This paper presents a detailed hydrostatic model of the upper atmosphere of HD 189733b, with the goal of constraining its temperature, particle densities, and radiation field over the pressure range 10-4 to 10 µbar, where the observed Hα transmission spectrum is produced. The atomic hydrogen level population is computed including …
Spectroscopy and Photometry of Multiple Populations along the Asymptotic Giant Branch of NGC 2808 and NGC 6121 (M4)
Milone, A. P.; Marino, A. F.; Bedin, L. R. +8 more
We present a photometric and spectroscopic study of multiple populations along the asymptotic giant branch (AGB) of the intermediate-metallicity globular clusters (GCs) NGC 2808 and NGC 6121 (M4). Chemical abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Co, Ni, Zn, Y, and Ce in AGB stars from high-resolution FLAMES+UVES@VLT spectra are rep…
Near-infrared MOSFIRE Spectra of Dusty Star-forming Galaxies at 0.2 < z < 4
Casey, Caitlin M.; Sanders, D. B.; Capak, Peter +6 more
We present near-infrared and optical spectroscopic observations of a sample of 450 and 850 µm-selected dusty star-forming galaxies (DSFGs) identified in a 400 arcmin2 area in the COSMOS field. Thirty-one sources of the 114 targets were spectroscopically confirmed at 0.2< z< 4, identified primarily in the near-infrared with K…
Extended Main-sequence Turn-offs in Intermediate-age Star Clusters: Stellar Rotation Diminishes, but Does Not Eliminate, Age Spreads
Girardi, Léo; Goudfrooij, Paul; Correnti, Matteo
Extended main-sequence turn-off (eMSTO) regions are a common feature in color-magnitude diagrams of young- and intermediate-age star clusters in the Magellanic Clouds. The nature of eMSTOs remains debated in the literature. The currently most popular scenarios are extended star formation activity and ranges of stellar rotation rates. Here we study…
Bimodal Long-lasting Components in Short Gamma-Ray Bursts: Promising Electromagnetic Counterparts to Neutron Star Binary Mergers
Sakamoto, Takanori; Kisaka, Shota; Ioka, Kunihito
Long-lasting emission of short gamma-ray bursts (GRBs) is crucial to reveal the physical origin of the central engine as well as to detect electromagnetic (EM) counterparts to gravitational waves (GWs) from neutron star binary mergers. We investigate 65 X-ray light curves of short GRBs, which is six times more than previous studies, by combining b…
Virgo Redux: The Masses and Stellar Content of Nuclei in Early-type Galaxies from Multiband Photometry and Spectroscopy
Cuillandre, Jean-Charles; Gwyn, Stephen; Côté, Patrick +14 more
We present an analysis of 39 nuclei and their early-type hosts in the Virgo Cluster using 10 broadband filters: F300W, F475W, F850LP, F160W, {u}* {\text{}}{griz}, and K s . We describe the Virgo Redux program, which provides high-resolution UV and NIR imaging. Combining this data with optical and NIR imaging from the ACS Vir…
Far-infrared to Millimeter Data of Protoplanetary Disks: Dust Growth in the Taurus, Ophiuchus, and Chamaeleon I Star-forming Regions
Bouy, Hervé; Naylor, David A.; Calvet, Nuria +7 more
Far-infrared and (sub)millimeter fluxes can be used to study dust in protoplanetary disks, the building blocks of planets. Here, we combine observations from the Herschel Space Observatory with ancillary data of 284 protoplanetary disks in the Taurus, Chamaeleon I, and Ophiuchus star-forming regions, covering from the optical to mm/cm wavelengths.…
Hierarchical Star Formation in Turbulent Media: Evidence from Young Star Clusters
Dale, D. A.; Calzetti, D.; Ryon, J. E. +16 more
We present an analysis of the positions and ages of young star clusters in eight local galaxies to investigate the connection between the age difference and separation of cluster pairs. We find that star clusters do not form uniformly but instead are distributed so that the age difference increases with the cluster pair separation to the 0.25-0.6 …
Dust-polarization Maps and Interstellar Turbulence
Kamionkowski, Marc; Caldwell, Robert R.; Hirata, Chris
Perhaps the most intriguing result of Planck’s dust-polarization measurements is the observation that the power in the E-mode polarization is twice that in the B mode, as opposed to pre-Planck expectations of roughly equal dust powers in the E and B modes. Here we show how the E- and B-mode powers depend on the detailed properties of the fluctuati…
Surges and Si IV Bursts in the Solar Atmosphere: Understanding IRIS and SST Observations through RMHD Experiments
Martínez-Sykora, J.; Rouppe van der Voort, L.; Moreno-Insertis, F. +1 more
Surges often appear as a result of the emergence of magnetized plasma from the solar interior. Traditionally, they are observed in chromospheric lines such as Hα 6563 \mathringA and Ca II 8542 \mathringA . However, whether there is a response to the surge appearance and evolution in the Si IV lines or, in fact, in many other transition region line…