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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…
A test of the planet-star unipolar inductor for magnetic white dwarfs
Hermes, J. J.; Marsh, T. R.; Bagnulo, S. +7 more
Despite thousands of spectroscopic detections, only four isolated white dwarfs exhibit Balmer emission lines. The temperature inversion mechanism is a puzzle over 30 years old that has defied conventional explanations. One hypothesis is a unipolar inductor that achieves surface heating via ohmic dissipation of a current loop between a conducting p…
Project MOMO: Multiwavelength Observations and Modeling of OJ 287
Ciprini, S.; Komossa, S.; Gallo, L. C. +9 more
Our project MOMO (Multiwavelength observations and modeling of OJ 287) consists of dedicated, dense, long-term flux and spectroscopic monitoring, and deep follow-up observations of the blazar OJ 287 at >13 frequencies from the radio to the X-ray band since late 2015. In particular, we are using Swift to obtain optical-UV-X-ray spectral energy 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 …
Forward modelling of Kepler-band variability due to faculae and spots
Solanki, Sami K.; Shapiro, Alexander I.; Krivova, Natalie +4 more
Variability observed in photometric light curves of late-type stars (on time-scales longer than a day) is a dominant noise source in exoplanet surveys and results predominantly from surface manifestations of stellar magnetic activity, namely faculae and spots. The implementation of faculae in light-curve models is an open problem, with scaling typ…
Discovery of O stars in the tidal Magellanic Bridge. Stellar parameters, abundances, and feedback of the nearest metal-poor massive stars and their implication for the Magellanic System ecology
Hamann, W. -R.; Oskinova, L. M.; Ramachandran, V.
The Magellanic Bridge, stretching between the Small and the Large Magellanic Cloud (SMC and LMC), is the nearest tidally stripped intergalactic environment. The Bridge has a significantly low average metallicity of Z ≲ 0.1 Z⊙. Here we report the first discovery of O-type stars in the Magellanic Bridge. Three massive O stars were identif…
Galactic extinction laws - II. Hidden in plain sight, a new interstellar absorption band at 7700 Å broader than any known DIB
Caballero, J. A.; Bohlin, R. C.; Maíz Apellániz, J. +2 more
We have detected a broad interstellar absorption band centred close to 7700 Å and with a full width at half-maximum (FWHM) of 176.6 ± 3.9 Å. This is the first such absorption band detected in the optical range and is significantly wider than the numerous diffuse interstellar bands (DIBs). It remained undiscovered until now because it is partially …
A search for variable subdwarf B stars in TESS Full Frame Images - II. Variable objects in the northern ecliptic hemisphere
Sahoo, S. K.; Baran, A. S.; Ostrowski, J. +1 more
We report the results of our search for pulsating subdwarf B stars in Full Frame Images collected during Year 2 of the TESS mission and covering the northern ecliptic hemisphere. This is a continuation of our effort we presented in Paper I. We found 13 likely new pulsating subdwarf B stars, 10 pulsating candidates that are identified as other hot …
Cosmological constraints on Hořava gravity revised in light of GW170817 and GRB170817A and the degeneracy with massive neutrinos
Frusciante, Noemi; Benetti, Micol
We revise the cosmological bounds on Hořava gravity, taking into account the stringent constraint on the speed of propagation of gravitational waves from GW170817 and GRB170817A. In light of this, we also investigate the degeneracy between massive neutrinos and Hořava gravity. We show that a luminal propagation of gravitational waves suppresses th…