Search Publications
Measurements of the Ca II infrared triplet emission lines of pre-main-sequence stars
Itoh, Yoichi; Takagi, Yuhei; Yamashita, Mai
We investigated the chromospheric activity of 60 pre-main-sequence (PMS) stars in four molecular clouds and five moving groups. It is considered that strong chromospheric activity is driven by the dynamo processes generated by stellar rotation. In contrast, several researchers have pointed out that the chromospheres of PMS stars are activated by m…
Time-sequence Spectroscopy of Epsilon CrA: The 518 nm Mg I Triplet Region Analyzed with Broadening Functions
Rucinski, Slavek M.
High-resolution spectroscopic observations of the W UMa-type binary ɛ CrA obtained as a time-monitoring sequence on four full and four partial nights within two weeks have been used to derive orbital elements of the system and discuss the validity of the Lucy model for description of the radial-velocity data. The observations had more extensive te…
The star formation properties of the observed and simulated AGN Universe: BAT versus EAGLE
Alexander, D. M.; Bower, R. G.; Rosario, D. J. +3 more
In this paper, we present data from 72 low-redshift, hard X-ray selected active galactic nucleus (AGN) taken from the Swift-BAT 58 month catalogue. We utilize spectral energy distribution fitting to the optical to infrared photometry in order to estimate host galaxy properties. We compare this observational sample to a volume- and flux-matched sam…
VIBES: Visual Binary Exoplanet survey with SPHERE. Upper limits on wide S-planet and S-BD frequencies, triple system discovery, and astrometric confirmation of 20 stellar binaries and three triple systems
Quanz, S. P.; Meyer, M.; Jayawardhana, R. +7 more
Context. Recent surveys indicate that planets in binary systems are more abundant than previously thought, which is in agreement with theoretical work on disc dynamics and planet formation in binaries. So far, most observational surveys, however, have focused on short-period planets in binaries, thus little is known about the occurrence rates of p…
Crepuscular Rays from the Highly Inclined Active Galactic Nucleus in IC 5063
Ho, Luis C.; Elvis, Martin; Barth, Aaron J. +10 more
On Earth near sunset, the Sun may cast "crepuscular rays" such that clouds near the horizon obscure the origin of light scattered in bright rays. In principle, active galactic nuclei (AGN) should be able to produce similar effects. Using new Hubble Space Telescope (HST) near-infrared and optical observations, we show that the active galaxy IC 5063…
A qualitative classification of extraterrestrial civilizations
Minniti, Dante; Ivanov, Valentin D.; Cáceres, Claudio +1 more
Context. Interest in searches for extraterrestrial civilizations (ETCs) has been boosted in recent decades by the discovery of thousands of exoplanets.
Aims: We turn to the classification of ETCs for new considerations that may help to design better strategies for searching for ETCs.
Methods: This study is based on analogies with our own…
An extreme-mass ratio, short-period eclipsing binary consisting of a B dwarf primary and a pre-main-sequence M star companion discovered by KELT
Bieryla, Allyson; Latham, David W.; Berlind, Perry +21 more
We present the discovery of KELT J072709 + 072007 (HD 58730), a very low mass ratio (q ≡ M2/M1 ≈ 0.07) eclipsing binary (EB) identified by the Kilodegree Extremely Little Telescope (KELT) survey. We present the discovery light curve and perform a global analysis of four high-precision ground-based light curves, the Transiting…
Polarimetric and radiative transfer modelling of HD 172555
Scicluna, Peter; Bailey, Jeremy; Cotton, Daniel V. +3 more
The debris disc around HD 172555 was recently imaged in near-infrared polarized scattered light by the Very Large Telescope's Spectro-Polarimetric High-contrast Exoplanet REsearch instrument. Here we present optical aperture polarization measurements of HD 172555 by the HIgh Precision Polarimetric Instrument (HIPPI), and its successor HIPPI-2 on t…
Hard X-ray properties of radio-selected blazars
Gehrels, N.; Wilms, J.; Kadler, M. +6 more
Context. Hard X-ray properties of beamed active galactic nuclei have been published in the 105-month Swift/BAT catalog, but there have not been any studies carried out so far on a well-defined, radio-selected sample of low-peaked blazars in the hard X-ray band.
Aims: Using the statistically complete MOJAVE-1 sample, we aim to determine the ha…
The White Dwarf Binary Pathways Survey -III. Contamination from hierarchical triples containing a white dwarf
Gänsicke, B. T.; Koester, D.; Parsons, S. G. +12 more
The White Dwarf Binary Pathways Survey aims at increasing the number of known detached A, F, G, and K main-sequence stars in close orbits with white dwarf companions (WD+AFGK binaries) to refine our understanding about compact binary evolution and the nature of Supernova Ia progenitors. These close WD+AFGK binary stars are expected to form through…