Search Publications
Gaia uncovers difference in B and Be star binarity at small scales: evidence for mass transfer causing the Be phenomenon
Oudmaijer, René D.; Vioque, Miguel; Dodd, Jonathan M. +2 more
Be stars make up almost 20 per cent of the B star population, and are rapidly rotating stars surrounded by a disc; however the origin of this rotation remains unclear. Mass transfer within close binaries provides the leading hypothesis, with previous detections of stripped companions to Be stars supporting this. Here, we exploit the exquisite astr…
The rate and contribution of mergers to mass assembly from NIRCam observations of galaxy candidates up to 13.3 billion years ago
Santini, Paola; Calabrò, Antonello; Castellano, Marco +8 more
We present an analysis of the galaxy merger rate in the redshift range
The host dark matter haloes of the first quasars
Costa, Tiago
If z > 6 quasars reside in rare, massive haloes, ΛCDM cosmology predicts they should be surrounded by an anomalously high number of bright companion galaxies. Here, I show that these companion galaxies should also move unusually fast. Using a new suite of cosmological, 'zoom-in' hydrodynamic simulations, I present predictions for the velocity d…
DEIMOS spectroscopy of z = 6 protocluster candidate in COSMOS - a massive protocluster embedded in a large-scale structure?
Casey, Caitlin M.; Zavala, Jorge A.; Brammer, Gabriel +14 more
We present the results of our Keck/DEep Imaging Multi-Object Spectrograph spectroscopic follow-up of candidate galaxies of I-band-dropout protocluster candidate galaxies at z ~ 6 in the COSMOS field. We securely detect Lyman α emission lines in 14 of the 30 objects targeted, 10 of them being at z = 6 with a signal-to-noise ratio of 5-20; the remai…
GalaxyFlow: upsampling hydrodynamical simulations for realistic mock stellar catalogues
Lim, Sung Hak; Raman, Kailash A.; Buckley, Matthew R. +1 more
Cosmological N-body simulations of galaxies operate at the level of 'star particles' with a mass resolution on the scale of thousands of solar masses. Turning these simulations into stellar mock catalogues requires 'upsampling' the star particles into individual stars following the same phase-space density. In this paper, we introduce two new upsa…
The dynamic centres of infrared-dark clouds and the formation of cores
Peretto, Nicolas; Ragan, Sarah E.; Watkins, Elizabeth J. +7 more
High-mass stars have an enormous influence on the evolution of the interstellar medium in galaxies, so it is important that we understand how they form. We examine the central clumps within a sample of seven infrared-dark clouds (IRDCs) with a range of masses and morphologies. We use 1-pc-scale observations from the Northern Extended Millimeter Ar…
Identification and characterization of six spectroscopically confirmed massive protostructures at 2.5 < z < 4.5
Shen, Lu; Koekemoer, Anton M.; Tresse, Laurence +22 more
We present six spectroscopically confirmed massive protostructures, spanning a redshift range of 2.5 < z < 4.5 in the Extended Chandra Deep Field South (ECDFS) field discovered as part of the Charting Cluster Construction in VUDS and ORELSE (C3VO) survey. We identify and characterize these remarkable systems by applying an overdensity measur…
Action and energy clustering of stellar streams in deforming Milky Way dark matter haloes
Sanders, Jason L.; Petersen, Michael S.; Brooks, Richard A. N. +2 more
We investigate the non-adiabatic effect of time-dependent deformations in the Milky Way (MW) halo potential on stellar streams. Specifically, we consider the MW's response to the infall of the Large Magellanic Cloud (LMC) and how this impacts our ability to recover the spherically averaged MW mass profile from observation using stream actions. Pre…
A targeted radio pulsar survey of redback candidates with MeerKAT
Ransom, S. M.; Calore, F.; Possenti, A. +18 more
Redbacks are millisecond pulsar binaries with low-mass, irradiated companions. These systems have a rich phenomenology that can be used to probe binary evolution models, pulsar wind physics, and the neutron star mass distribution. A number of high-confidence redback candidates have been identified through searches for variable optical and X-ray so…
Geometry-driven and dark-matter-sustained Milky Way rotation curves with Gaia DR3
Lattanzi, Mario G.; Crosta, Mariateresa; Beordo, William +2 more
Thanks to Gaia DR2, we proved for the first time that a general relativistic Milky Way rotation curve is statistically indistinguishable from its state-of-the-art dark matter analogue. Those results supported the ansatz that gravitational dragging can explain the observed flatness of the Milky Way rotation curve with a consistent radial matter den…