Search Publications
Measuring distances to galaxies with globular cluster velocity dispersions
Beasley, Michael A.; Fahrion, Katja; Gvozdenko, Anastasia
Accurate distances are key to obtaining intrinsic properties of astronomical objects such as luminosity or size. Globular clusters (GCs) follow a well-defined relation between their absolute magnitudes and internal stellar velocity dispersions (σ), offering an independent way to measure distances to their host galaxies via high-resolution spectros…
Energy dependence of quasi-periodic oscillations in accreting X-ray pulsars
Paul, Biswajit; Pradhan, Pragati; Sharma, Rahul +2 more
We present the results from an investigation of the energy dependence of quasi-periodic oscillations (QPOs) exhibited by accreting X-ray pulsars using data from archival XMM-Newton, NuSTAR, RXTE, and NICER observations. In a search for the presence of QPOs in 99 XMM-Newton and NuSTAR observations, we detected QPOs in eleven observations of five so…
Stochastic prior for non-parametric star-formation histories
Maiolino, Roberto; Johnson, Benjamin D.; Tacchella, Sandro +3 more
The amount of power contained in the variations in galaxy star-formation histories (SFHs) across a range of time-scales encodes key information about the physical processes which modulate star formation. Modelling the SFHs of galaxies as stochastic processes allows the relative importance of different time-scales to be quantified via the power spe…
The rise and fall of dust in the Universe
Eales, Stephen; Ward, Bradley
We estimate how the mean density of dust in the Universe varies with redshift, using submillimetre continuum observations and a method designed to minimize the effect of dust temperature. We have used the Herschel Astrophysical Terahertz Large Area Survey (Herschel-ATLAS) to show that the median temperature of dust in galaxies is $\simeq 22\ \math…
Revisiting the Dragonfly galaxy II. Young, radiatively efficient radio-loud AGN drives massive molecular outflow in a starburst merger at z = 1.92
Inoue, Akio K.; Sugahara, Yuma; Kaneko, Hiroyuki +4 more
Radio-loud active galactic nuclei (RLAGNs) are a unique AGN population and were thought to be preferentially associated with supermassive black holes (SMBHs) at low accretion rates. They could impact the host galaxy evolution by expelling cold gas through the jet-mode feedback. In this work, we studied CO(6-5) line emission and continuum emission …
Signatures of gas flows - I. Connecting the kinematics of the H I circumgalactic medium to galaxy rotation
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +5 more
The circumgalactic medium (CGM) hosts many physical processes with different kinematic signatures that affect galaxy evolution. We address the CGM-galaxy kinematic connection by quantifying the fraction of H I that is aligned with galaxy rotation with the equivalent width co-rotation fraction, $f_{\rm EWcorot}$. Using 70 quasar sightlines having H…
An overlooked source of uncertainty in the mass of the Milky Way
Riley, Alexander H.; Oman, Kyle A.
In the conventional approach to decomposing a rotation curve into a set of contributions from mass model components, the measurements of the rotation curve at different radii are taken to be independent. It is clear, however, that radial correlations are present in such data, for instance (but not only) because the orbital speed depends on the mas…
The impact of bar origin and morphology on stellar migration
Kawata, Daisuke; Okamoto, Takashi; Pettitt, Alex R. +1 more
Different mechanisms driving bar structure formation indicate that bar origins should be distinguishable in the stellar populations of galaxies. To study how these origins affect different bar morphologies and impact stellar orbits and migration, we analyse three simulated discs which are representative of bar formation under isolated evolution mo…
Modelling the AM CVn and double detonation supernova progenitor binary system CD-30°11223
Kupfer, Thomas; Deshmukh, Kunal; Bauer, Evan B. +1 more
We present a detailed modelling study of CD-30°11223 (CD-30), a hot subdwarf (sdB)-white dwarf (WD) binary identified as a double detonation supernova progenitor, using the open-source stellar evolution software MESA. We focus on implementing binary evolution models carefully tuned to match the observed characteristics of the system including log …
Gas content and evolution of a sample of YSO associations at d ≲ 3.5 kpc from the Sun
Li, Guang-Xing; Chen, Bing-Qiu; Zhou, Ji-Xuan
Young Stellar Objects (YSO) are newly formed stars from molecular clouds. They stay close to where they were born and serve as good tracers to study gas and star formation. During cloud evolution, young massive stars can disrupt the surrounding gas through stellar feedback, changing the gas distribution. We study the distribution of the gas around…