Search Publications
Physical properties of β Lyrae A and its opaque accretion disk
Wolf, M.; Meilland, A.; Baron, F. +23 more
Mass exchange and mass loss in close binaries can significantly affect their evolution, but a complete self-consistent theory of these processes is still to be developed. Processes such as radiative shielding due to a hot-spot region, or a hydrodynamical interaction of different parts of the gas stream have been studied previously. In order to tes…
Solar chromospheric emission and magnetic structures from plages to intranetwork: Contribution of the very quiet Sun
Meunier, N.
Context. We need to establish a correspondence between the magnetic structures generated by models and usual stellar activity indexes to simulate radial velocity time series for stars less active than the Sun. This is necessary to compare the outputs of such models with observed radial velocity jitters and is critical to better understand the impa…
The 7-year MAXI/GSC Source Catalog of the Low-Galactic-latitude Sky (3MAXI)
Sakamoto, T.; Mihara, T.; Sugizaki, M. +28 more
We present the first MAXI/GSC X-ray source catalog in the low-Galactic-latitude sky | b| < 10^\circ outside the Galactic center region (| b| < 5^\circ , l < 30°, and l > 330°) based on 7-year data from 2009 August 13 to 2016 July 31. To overcome source confusion in crowded regions, we have accurately calibrated the position-dependent s…
Helium Reionization Simulations. III. The Helium Lyα Forest
Trac, Hy; La Plante, Paul; Croft, Rupert +1 more
In a previous paper we presented a new suite of hydrodynamic simulations with the aim of accurately capturing the process of helium II reionization. In this paper, we discuss the observational signatures present in the He II Lyα forest. We show that the effective optical depth of the volume-averaged τ eff alone is not sufficient for cap…
Mass Modeling of Frontier Fields Cluster MACS J1149.5+2223 Using Strong and Weak Lensing
Treu, Tommaso; Bradač, Maruša; Schrabback, Tim +8 more
We present a gravitational-lensing model of MACS J1149.5+2223 using ultra-deep Hubble Frontier Fields imaging data and spectroscopic redshifts from HST grism and Very Large Telescope (VLT)/MUSE spectroscopic data. We create total mass maps using 38 multiple images (13 sources) and 608 weak-lensing galaxies, as well as 100 multiple images of 31 sta…
Optical and near-infrared IFU spectroscopy of the nuclear region of the AGN-starburst galaxy NGC 7582
Ricci, T. V.; Steiner, J. E.; May, D. +2 more
NGC 7582 is an SB(s)ab galaxy which displays evidences of simultaneous nuclear activity and star formation in its centre. Previous optical observations revealed, besides the H II regions, an ionization cone and a gas disc in its central part. Hubble Space Telescope (HST) images in both optical and infrared bands show the active galactic nuclei (AG…
Tracing the assembly history of NGC 1395 through its Globular Cluster System
Forte, Juan C.; Faifer, Favio R.; González, Nélida M. +4 more
We used deep Gemini-South/GMOS g΄r΄i΄z΄ images to study the globular cluster (GC) system of the massive elliptical galaxy NGC 1395, located in the Eridanus supergroup. The photometric analysis of the GC candidates reveals a clear colour bimodality distribution, indicating the presence of `blue' and `red'…
A deep near-infrared spectroscopic survey of the Scutum-Crux arm for Wolf-Rayet stars
Crowther, Paul A.; Rosslowe, C. K.
We present a New Technology Telescope/Son-of-Isaac spectroscopic survey of infrared selected Wolf-Rayet (WR) candidates in the Scutum-Crux spiral arm (298° ≤ l ≤ 340°, |b| ≤ 0.5°. We obtained near-IR spectra of 127 candidates, revealing 17 WR stars - a ∼13 per cent success rate - of which 16 are newly identified here. The majority of the new WR st…
A Slowly Precessing Disk in the Nucleus of M31 as the Feeding Mechanism for a Central Starburst
Ghez, A. M.; Rich, R. M.; Lu, J. R. +3 more
We present a kinematic study of the nuclear stellar disk in M31 at infrared wavelengths using high spatial resolution integral field spectroscopy. The spatial resolution achieved, FWHM = 0.″12 (0.45 pc at the distance of M31), has only previously been equaled in spectroscopic studies by space-based long-slit observations. Using adaptive-optics-cor…
Parallaxes of Cool Objects with WISE: Filling in for Gaia
Theissen, Christopher A.
This paper uses the multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE) to demonstrate a method to measure proper motions and trigonometric parallaxes with precisions of ∼4 mas yr-1 and ∼7 mas, respectively, for low-mass stars and brown dwarfs. This method relies on WISE single exposures (Level 1b frames) and a Ma…