Search Publications
An eccentric companion at the edge of the brown dwarf desert orbiting the 2.4 M⊙ giant star HIP 67537
Wittenmyer, R. A.; Jones, M. I.; Drass, H. +5 more
We report the discovery of a substellar companion around the giant star HIP 67537. Based on precision radial velocity measurements from CHIRON and FEROS high-resolution spectroscopic data, we derived the following orbital elements for HIP 67537 b: mb sin I = 11.1+0.4-1.1Mjup, a =4.9+0.14-…
Gaia Data Release 1. Validation of the photometry
Jordi, C.; Evans, D. W.; Brown, A. G. A. +12 more
Aims: The photometric validation of the Gaia DR1 release of the ESA Gaia mission is described and the quality of the data shown.
Methods: This is carried out via an internal analysis of the photometry using the most constant sources. Comparisons with external photometric catalogues are also made, but are limited by the accuracies and sys…
LOFAR observations of decameter carbon radio recombination lines towards Cassiopeia A
van Weeren, R. J.; Tielens, A. G. G. M.; Röttgering, H. J. A. +6 more
We present a study of carbon radio recombination lines towards Cassiopeia A using low frequency array (LOFAR) observations in the frequency range 10-33 MHz. Individual carbon α lines are detected in absorption against the continuum at frequencies as low as 16 MHz. Stacking several Cα lines we obtain detections in the 11-16 MHz range. These are the…
Constraints on AGN feedback from its Sunyaev-Zel'dovich imprint on the cosmic background radiation
Sijacki, Debora; Efstathiou, George; Puchwein, Ewald +2 more
We derive constraints on feedback by active galactic nuclei (AGN) by setting limits on their thermal Sunyaev-Zel'dovich (SZ) imprint on the cosmic microwave background. The amplitude of any SZ signature is small and degenerate with the poorly known sub-mm spectral energy distribution of the AGN host galaxy and other unresolved dusty sources along …
Hard X-ray variability of V404 Cygni during the 2015 outburst
Motta, S. E.; Sánchez-Fernández, C.; Kuulkers, E. +1 more
Aims: Hard X-ray spectra of black hole binaries (BHB) are produced by Comptonization of soft seed photons by hot electrons near the black hole. The slope of the resulting energy spectra is governed by two main parameters: the electron temperature (Te) and optical depth (τ) of the emitting plasma. Given the extreme brightness of V40…
Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko
Wurz, P.; Altwegg, K.; Balsiger, H. +17 more
Context. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) was designed to measure the composition of the gas in the coma of comet 67P/Churyumov-Gerasimenko, the target of the European Space Agency's Rosetta mission. In addition to the volatiles, ROSINA measured refractories sputtered off the comet by the interaction of solar …
Inflationary features and shifts in cosmological parameters from Planck 2015 data
Dvorkin, Cora; Obied, Georges; Miranda, Vinicius +2 more
We explore the relationship between features in the Planck 2015 temperature and polarization data, shifts in the cosmological parameters, and features from inflation. Residuals in the temperature data from the best-fit power-law Λ CDM model at low multipole ℓ≲40 are mainly responsible for the high H0 and low σ8Ωm
ALMA deep field in SSA22: Blindly detected CO emitters and [C II] emitter candidates
Smail, Ian; Fujimoto, Seiji; Inoue, Akio K. +21 more
We report the identification of four millimeter line-emitting galaxies with the Atacama Large Milli/submillimeter Array (ALMA) in SSA22 Field (ADF22). We analyze the ALMA 1.1-mm survey data, with an effective survey area of 5 arcmin2, frequency ranges of 253.1-256.8 and 269.1-272.8 GHz, angular resolution of 0{^''.}7 and rms …
Crowded Field Galaxy Photometry: Precision Colors in the CLASH Clusters
Koekemoer, Anton M.; Donahue, Megan; Voit, G. Mark +8 more
We present a new method for photometering objects in galaxy clusters. We introduce a mode-filtering technique for removing spatially variable backgrounds, improving both detection and photometric accuracy (roughly halving the scatter in the red sequence compared to previous catalogs of the same clusters). This method is based on robustly determini…
Chromospherically Active Stars in the RAVE Survey. II. Young Dwarfs in the Solar Neighborhood
Gilmore, G.; Freeman, K. C.; Munari, U. +19 more
A large sample of over 38,000 chromospherically active candidate solar-like stars and cooler dwarfs from the RAVE survey is addressed in this paper. An improved activity identification with respect to the previous study was introduced to build a catalog of field stars in the solar neighborhood with an excess emission flux in the calcium infrared t…