Search Publications
Entropy-driven winds: Outflows and fountains lifted gently by buoyancy
Kruijssen, J. M. Diederik; Keller, Benjamin W.; Wadsley, James W.
We present a new theoretical framework for using entropy to understand how outflows driven by supernovae are launched from disc galaxies: via continuous, buoyant acceleration through the circumgalactic medium (CGM). When young star clusters detonate supernovae in the interstellar medium (ISM) of a galaxy, they generate hot, diffuse bubbles that pu…
The evolution of neutral hydrogen over the past 11 Gyr via H I 21 cm absorption
Bolatto, Alberto D.; Leroy, Adam K.; Grasha, Kathryn +1 more
We present the results of a blind search for intervening H I 21 cm absorption towards 260 radio sources in the redshift range 0 < z < 2.74 with the Green Bank Telescope. The survey has the sensitivity to detect sub-damped Ly α (DLA) systems for H I spin temperatures Ts/f = 100 K, and despite the successful re-detection of 10 known…
Two Wolf-Rayet stars at the heart of colliding-wind binary Apep
Callingham, J. R.; Crowther, P. A.; Marcote, B. +4 more
Infrared imaging of the colliding-wind binary Apep has revealed a spectacular dust plume with complicated internal dynamics that challenges standard colliding-wind binary physics. Such challenges can be potentially resolved if a rapidly rotating Wolf-Rayet star is located at the heart of the system, implicating Apep as a Galactic progenitor system…
NEPSC2, the North Ecliptic Pole SCUBA-2 survey: 850-µm map and catalogue of 850-µm-selected sources over 2 deg2
Hashimoto, Tetsuya; Kim, Seong Jin; Conselice, Christopher J. +27 more
We present an 850-µm mosaic map and extracted catalogue of submillimetre sources in the extended North Ecliptic Pole (NEP) region over about 2 deg2. The 850-µm map is constructed using newly obtained observations by SCUBA-2 at the East Asian Observatory's James Clerk Maxwell Telescope, carried out using the observatory's lar…
An updated detailed characterization of planes of satellites in the MW and M31
Pawlowski, Marcel S.; Santos-Santos, Isabel M.; Domínguez-Tenreiro, Rosa
We present a detailed characterization of planes of satellite galaxies in the Milky Way (MW) and M31. For a positional analysis, we introduce an extension to the '4-galaxy-normal density plot' method from Pawlowski, Kroupa & Jerjen. It finds the normal directions to the predominant planar configurations of satellites of a system, yielding for …
The chemical nature of the young 120-Myr-old nearby Pisces-Eridanus stellar stream flowing through the Galactic disc
Curtis, Jason; Hawkins, Keith; Lucey, Madeline
Recently, a new cylindrical-shaped stream of stars up to 700 pc long was discovered hiding in the Galactic disc using kinematic data enabled by the Gaia mission. This stream of stars, dubbed Pisces-Eridanus (Psc-Eri), was initially thought to be as old as 1 Gyr, yet its stars shared a rotation period distribution consistent with a population that …
Observability of dusty debris discs around M-stars
Lestrade, Jean-François; Booth, Mark; Krivov, Alexander V. +1 more
Debris discs are second-generation dusty discs formed by collisions of planetesimals. Many debris discs have been found and resolved around hot and solar-type stars. However, only a handful have been discovered around M-stars, and the reasons for their paucity remain unclear. Here, we check whether the sensitivity and wavelength coverage of presen…
Modelling X-ray RMS spectra I: intrinsically variable AGNs
Fabian, A. C.; Alston, W. N.; Parker, M. L. +1 more
We present simple XSPEC models for fitting excess variance spectra of active galactic nuclei. Using a simple Monte Carlo approach, we simulate a range of spectra corresponding to physical parameters varying, then calculate the resulting variance spectra. Starting from a variable power law, we build up a set of models corresponding to the different…
Very wide companion fraction from Gaia DR2: A weak or no enhancement for hot Jupiter hosts, and a strong enhancement for contact binaries
Zakamska, Nadia L.; Schlaufman, Kevin C.; Hwang, Hsiang-Chih +1 more
There is an ongoing debate on whether hot Jupiter hosts are more likely to be found in wide binaries with separations of ≳100 AU. In this paper, we search for comoving, very wide companions with separations of 103-104 AU for hot Jupiter hosts and main-sequence contact binaries in Gaia DR2, and compare the very wide companion …
Average cometary ion flow pattern in the vicinity of comet 67P from moment data
Nilsson, Hans; Behar, Etienne; Goetz, Charlotte +7 more
Average flow patterns of ions around comet 67P detected by the RPC-ICA instrument onboard Rosetta are presented both as a time series and as a spatial distribution of the average flow in the plane perpendicular to the comet - Sun direction (Y-Z plane in the coordinate systems used). Cometary ions in the energy range up to 60 eV flow radially away …