Search Publications
Optical design of the High Resolution Imaging Channel of SIMBIO-SYS
Cremonese, Gabriele; Palumbo, Pasquale; Zusi, Michele +4 more
Active Asteroid P/2017 S5 (ATLAS)
Mutchler, Max; Kotulla, Ralf; Jewitt, David +7 more
Observations of active asteroid P/2017 S5 when near perihelion reveal the ejection of large (102-104 µm) particles at 0.2-2 m s-1 speeds, with estimated mass-loss rates of a few kg s-1. The protracted nature of the mass loss (continuous over ∼150 days) is compatible with a sublimation origin, meani…
Observability of hydrogen-rich exospheres in Earth-like exoplanets
dos Santos, Leonardo A.; Bourrier, Vincent; Ehrenreich, David +1 more
Context. The existence of an extended neutral hydrogen exosphere around small planets can be used as evidence of the presence of water in their lower atmosphere, but, to date, such a feature has not been securely detected in rocky exoplanets. Planetary exospheres can be observed using transit spectroscopy of the Lyman-α line, which is limited main…
Hot subdwarf wind models with accurate abundances. I. Hydrogen dominated stars HD 49798 and BD+18° 2647
Mereghetti, S.; Pintore, F.; Krtička, J. +5 more
Context. Hot subdwarfs are helium burning objects in late stages of their evolution. These subluminous stars can develop winds driven by light absorption in the lines of heavier elements. The wind strength depends on chemical composition which can significantly vary from star to star.
Aims: We aim to understand the influence of metallicity on…
A universal relation of dust obscuration across cosmic time
Zheng, Xian Zhong; Wuyts, Stijn; Pan, Zhizheng +2 more
We investigate dust obscuration as parametrized by the infrared excess IRX ≡ LIR/LUV in relation to global galaxy properties, using a sample of ∼32 000 local star-forming galaxies (SFGs) selected from SDSS (Sloan Digital Sky Survey), GALEX (Galaxy Evolution Explorer), and WISE (Wide-field Infrared Survey Explorer). We show th…
Electron Densities and Nitrogen Abundances in Ionized Gas Derived Using [N II] Fine-structure and Hydrogen Recombination Lines
Lazio, T. Joseph W.; Horiuchi, Shinji; Goldsmith, Paul F. +7 more
We present a method for deriving the electron density of ionized gas using the ratio of the intensity of the [N II] 205 µm line to that of hydrogen radio recombination lines (RRLs). We use this method to derive electron densities of 21 velocity components in 11 lines of sight through the Galaxy, including the Galactic center. We observed, at…
Identification of Stellar Flares Using Differential Evolution Template Optimization
Kowalski, Adam F.; Wisniewski, John P.; Bellm, Eric C. +2 more
We explore methods for the identification of stellar flare events in irregularly sampled data of ground-based time domain surveys. In particular, we describe a new technique for identifying flaring stars, which we have implemented in a publicly available Python module called “PyVAN.” The approach uses the Differential Evolution algorithm to optimi…
New Constraint on the Atmosphere of (50000) Quaoar from a Stellar Occultation
Kobayashi, Naoto; Maehara, Hiroyuki; Matsunaga, Noriyuki +35 more
We report observations of a stellar occultation by the classical Kuiper Belt object (50000) Quaoar that occurred on 2019 June 28. A single-chord high-cadence (2 Hz) photometry data set was obtained with the Tomo-e Gozen CMOS camera mounted on the 1.05 m Schmidt telescope at Kiso Observatory. The obtained ingress and egress data do not show any ind…
Detection of nitrogen gas in the β Pictoris circumstellar disc
Snellen, I. A. G.; Lecavelier des Etangs, A.; Bourrier, V. +4 more
Context. The gas composition of the debris disc surrounding β Pictoris is rich in carbon and oxygen relative to solar abundances. Two possible scenarios have been proposed to explain this enrichment. The preferential production scenario suggests that the produced gas may be naturally rich in carbon and oxygen, while the alternative preferential de…
Circumstellar CO in metal-poor stellar winds: the highly irradiated globular cluster star 47 Tucanae V3
Zijlstra, A. A.; Richards, A. M. S.; Boyer, M. L. +4 more
We report the first detection of circumstellar CO in a globular cluster. Observations with ALMA have detected the CO J = 3-2 and SiO v = 1 J = 8 - 7 transitions at 345 and 344 GHz, respectively, around V3 in 47 Tucanae (NGC 104; [Fe/H] = -0.72 dex), a star on the asymptotic giant branch. The CO line is detected at 7σ at a rest velocity vLSR