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Optical and Near-infrared Pulsation Properties of RR Lyrae and Population II Cepheid Variables in the Messier 15 Globular Cluster
Marconi, Marcella; Rejkuba, Marina; Yang, Soung-Chul +2 more
Messier 15 (NGC 7078) is an old and metal-poor post core-collapse globular cluster that hosts a rich population of variable stars. We report new optical (gi) and near-infrared (NIR, JKs) multi-epoch observations for 129 RR Lyrae, 4 Population II Cepheids (3 BL Herculis, 1 W Virginis), and 1 anomalous Cepheid variable candidate in M15 ob…
Could the Local Cavity be an Irregularly Shaped Strömgren Sphere?
Redfield, Seth; Linsky, Jeffrey L.
Extending for 50-200 pc in all directions from the Sun, the Local Cavity has been characterized as an old supernova bubble consisting of low-density million-degree plasma heated by supernova shocks. We summarize the arguments for and against this model and conclude that hydrogen in the Local Cavity is fully ionized, and the plasma near the Galacti…
The ALMA Spectroscopic Survey in the HUDF: A Search for [C II] Emitters at 6 ≤ z ≤ 8
Carilli, Chris; Inami, Hanae; Stefanon, Mauro +18 more
The Atacama Large Millimeter/submillimeter Array (ALMA) Spectroscopic Survey in the Hubble Ultra Deep Field (ASPECS) Band 6 scan (212-272 GHz) covers potential [C II] emission in galaxies at 6 ≤ z ≤ 8 throughout a 2.9 arcmin2 area. By selecting on known Lyα emitters (LAEs) and photometric dropout galaxies in the field, we perform target…
The McDonald Accelerating Stars Survey (MASS): Discovery of a Long-period Substellar Companion Orbiting the Old Solar Analog HD 47127
Cochran, William D.; Endl, Michael; Crepp, Justin R. +12 more
Brown dwarfs with well-determined ages, luminosities, and masses provide rare but valuable tests of low-temperature atmospheric and evolutionary models. We present the discovery and dynamical mass measurement of a substellar companion to HD 47127, an old (≈7-10 Gyr) G5 main-sequence star with a mass similar to the Sun. Radial velocities of the hos…
Tomography of the Unique Ongoing Jet in the Planetary Nebula NGC 2392
Guerrero, M. A.; Toalá, J. A.; Ramos-Larios, G. +5 more
Jets (fast collimated outflows) are claimed to be the main shaping agent of the most asymmetric planetary nebulae (PNs), as they impinge on the circumstellar material at late stages of the asymptotic giant branch phase. The first jet detected in a PN was that of NGC 2392, yet there is no available image because of its low surface brightness contra…
On the Nature of AGN and Star Formation Enhancement in the z = 3.1 SSA22 Protocluster: The HST WFC3 IR View
Kubo, Mariko; Umehata, Hideki; Alexander, David M. +9 more
We examine possible environmental sources of the enhanced star formation and active galactic nucleus (AGN) activity in the z = 3.09 SSA22 protocluster using Hubble WFC3 F160W (~1.6 µm) observations of the SSA22 field, including new observations centered on eight X-ray selected protocluster AGN. To investigate the role of mergers in the obser…
Photoionized Herbig-Haro Objects in the Orion Nebula through Deep High Spectral Resolution Spectroscopy. II. HH 204
Henney, W. J.; Méndez-Delgado, J. E.; Arellano-Córdova, K. Z. +3 more
We analyze the physical conditions, chemical composition, and other properties of the photoionized Herbig-Haro (HH) object HH 204 through Very Large Telescope echelle spectroscopy and Hubble Space Telescope imaging. We kinematically isolate the high-velocity emission of HH 204 from the emission of the background nebula and study the subarcsecond d…
ALMA 1.3 mm Survey of Lensed Submillimeter Galaxies Selected by Herschel: Discovery of Spatially Extended SMGs and Implications
Pérez-González, Pablo G.; Richard, Johan; Smail, Ian +19 more
We present an ALMA 1.3 mm (Band 6) continuum survey of lensed submillimeter galaxies (SMGs) at z = 1.0 to ∼3.2 with an angular resolution of ∼0"2. These galaxies were uncovered by the Herschel Lensing Survey and feature exceptionally bright far-infrared continuum emission (Speak ≳ 90 mJy) owing to their lensing magnification. We detect …
Magnetic and Rotational Evolution of ρ CrB from Asteroseismology with TESS
Kochukhov, Oleg; Drake, Jeremy J.; Stassun, Keivan G. +15 more
During the first half of main-sequence lifetimes, the evolution of rotation and magnetic activity in solar-type stars appears to be strongly coupled. Recent observations suggest that rotation rates evolve much more slowly beyond middle age, while stellar activity continues to decline. We aim to characterize this midlife transition by combining arc…
Benchmarking Dust Emission Models in M101
Gordon, Karl D.; Leroy, Adam K.; Koch, Eric W. +7 more
We present a comparative study of four physical dust models and two single-temperature modified blackbody models by fitting them to the resolved WISE, Spitzer, and Herschel photometry of M101 (NGC 5457). Using identical data and a grid-based fitting technique, we compare the resulting dust and radiation field properties derived from the models. We…