Search Publications
Canis Major OB1 stellar group contents revealed by Gaia
Mendes de Oliveira, C.; Borges Fernandes, M.; Bonatto, C. +15 more
Canis Major OB1 (CMa OB1) is a Galactic stellar association with a very intriguing star-formation scenario. There are more than two dozen known star clusters in its line of sight, but it is not clear which ones are physically associated with CMa OB1. We use a clustering code that employs five-dimensional data from the Gaia DR2 catalogue to identif…
Outbursts and stellar properties of the classical Be star HD 6226
Gies, Douglas R.; Wang, Luqian; Richardson, Noel D. +58 more
The bright and understudied classical Be star HD 6226 has exhibited multiple outbursts in the last several years during which the star grew a viscous decretion disc. We analyse 659 optical spectra of the system collected from 2017 to 2020, along with a ultraviolet spectrum from the Hubble Space Telescope and high cadence photometry from both Trans…
The history of metal enrichment traced by X-ray observations of high-redshift galaxy clusters
Allen, Steven W.; Canning, Rebecca E. A.; McDonald, Michael +7 more
We present the analysis of deep X-ray observations of 10 massive galaxy clusters at redshifts 1.05 < z < 1.71, with the primary goal of measuring the metallicity of the intracluster medium (ICM) at intermediate radii, to better constrain models of the metal enrichment of the intergalactic medium. The targets were selected from X-ray and Suny…
Quiescent galaxies in a virialized cluster at redshift 2: evidence for accelerated size growth
Brammer, G.; Stanford, S. A.; Allen, S. W. +4 more
We present an analysis of the galaxy population in XLSSC 122, an X-ray-selected, virialized cluster at redshift z = 1.98. We utilize Hubble Space Telescope (HST)Wide Field Camera 3 (WFC3) photometry to characterize the activity and morphology of spectroscopically confirmed cluster members. The quiescent fraction is found to be $88^{+4}_{-20}$ per …
The GALAH Survey: using galactic archaeology to refine our knowledge of TESS target stars
Ting, Yuan-Sen; Morton, Timothy D.; Wittenmyer, Robert A. +29 more
An unprecedented number of exoplanets are being discovered by the Transiting Exoplanet Survey Satellite (TESS). Determining the orbital parameters of these exoplanets, and especially their mass and radius, will depend heavily upon the measured physical characteristics of their host stars. We have cross-matched spectroscopic, photometric, and astro…
ALMA imaging of the M-dwarf Fomalhaut C's debris disc
Matthews, Brenda C.; Duchêne, Gaspard; Kalas, Paul +9 more
Fomalhaut C (LP 876-10) is a low mass M4V star in the intriguing Fomalhaut triple system and, like Fomalhaut A, possesses a debris disc. It is one of very few nearby M-dwarfs known to host a debris disc and of these has by far the lowest stellar mass. We present new resolved observations of the debris disc around Fomalhaut C with the Atacama Large…
Using binaries in globular clusters to catch sight of intermediate-mass black holes
Bianchini, Paolo; Mastrobuono-Battisti, Alessandra; Sippel, Anna C. +3 more
The dynamical evolution of globular clusters (GCs) is tied to their binary population, as binaries segregate to the cluster centre, leading to an increased binary fraction in the core. This central overabundance of mainly hard binaries can serve as a source of energy for the cluster and has a significant effect on the observed kinematics, such as …
Powerful multiphase outflows in the central region of Cygnus A
Riffel, R. A.
We use Gemini Near-Infrared Integral Field Spectrograph (NIFS) observations of the inner 3.5 × 3.5 kpc2 of the radio galaxy Cygnus A to map the gas excitation and kinematics at a spatial resolution of 200 pc. The emission of the ionized gas shows a biconical morphology, with half-opening angle of 45○ and oriented along the po…
Disentangling the multiphase circumgalactic medium shared between a dwarf and a massive star-forming galaxy at z∼0.4
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +4 more
The multiphase circumgalactic medium (CGM) arises within the complex environment around a galaxy, or collection of galaxies, and possibly originates from a wide range of physical mechanisms. In this paper, we attempt to disentangle the origins of these multiphase structures and present a detailed analysis of the quasar field Q0122-003 field using …
The first photometric and spectroscopic analysis of the extremely low mass-ratio contact binary NSVS 5029961
Li, Kai; Xia, Qi-Qi; Zheng, Shu-Yue
We performed photometric and spectroscopic investigations of NSVS 5029961 for the first time. The new BV(RI)c-band light curves were obtained with the 1.0-m telescope at Weihai Observatory of Shandong University. Applying the Wilson-Devinney program, we found that NSVS 5029961 is an A-subtype shallow contact binary with extremely low ma…