Search Publications
The effect of stellar multiplicity on protoplanetary discs: a near-infrared survey of the Lupus star-forming region
Ansdell, Megan; Pérez, Sebastián; Gonzalez-Ruilova, Camilo +9 more
We present results from a near-infrared (NIR) adaptive optics (AO) survey of pre-main-sequence stars in the Lupus molecular cloud with NACO at the Very Large Telescope (VLT) to identify (sub)stellar companions down to ~20-au separation and investigate the effects of multiplicity on circumstellar disc properties. We observe for the first time in th…
UV line-driven disc wind as the origin of UltraFast Outflows in AGN
Done, Chris; Mizumoto, Misaki; Odaka, Hirokazu +2 more
UltraFast Outflows (UFOs) are observed in some active galactic nuclei (AGN), with blueshifted and highly ionized Fe-K absorption features. AGN typically have an ultraviolet (UV-) bright accretion flow, so UV line driving is an obvious candidate for launching these winds. However this mechanism requires material with UV opacity, in apparent conflic…
A β Cephei pulsator and a changing orbital inclination in the high-mass eclipsing binary system VV Orionis
Bowman, D. M.; Southworth, John; Pavlovski, K.
We present an analysis of the high-mass eclipsing binary system VV Ori based on photometry from the TESS satellite. The primary star (B1 V, 9.5 $\, {\rm M}_\odot$) shows β Cephei pulsations and the secondary (B7 V, 3.8 $\, {\rm M}_\odot$) is possibly a slowly pulsating B star. We detect 51 significant oscillation frequencies, including two multipl…
The bursty star formation history of the Fornax dwarf spheroidal galaxy revealed with the HST
Monelli, M.; Cassisi, S.; Gallart, C. +4 more
We present a new derivation of the star formation history (SFH) of the dSph galaxy Fornax in two central regions, characterized by unprecedented precision and age resolution. It reveals that star formation has proceeded in sharp bursts separated by periods of low level or quiescent activity. The SFH was derived through colour-magnitude diagram (CM…
Double-peaked Lyman α emission at z = 6.803: a reionization-era galaxy self-ionizing its local H II bubble
Garel, Thibault; Verhamme, Anne; Ellis, Richard S. +2 more
We report the discovery of a double-peaked Lyman α profile in a galaxy at z = 6.803, A370p_z1, in the parallel Frontier Field of Abell 370. The velocity separation between the blue and red peaks of the Lyman α profile ( $\Delta v=101_{-19}^{+38} (\pm 48)\, \rm km\, \rm s^{-1}$ ) suggests an extremely high escape fraction of ionizing photons $\gt 5…
White dwarfs with planetary remnants in the era of Gaia - I. Six emission line systems
Pala, A. F.; Marsh, T. R.; Hollands, M. A. +17 more
White dwarfs with emission lines from gaseous debris discs are among the rarest examples of planetary remnant hosts, but at the same time they are key objects for studying the final evolutionary stage of planetary systems. Making use of the large number of white dwarfs identified in Gaia Data Release 2 (DR2), we are conducting a survey of planetar…
Measurement on the cosmic curvature using the Gaussian process method
Gong, Yungui; Yang, Yingjie
Inflation predicts that the Universe is spatially flat. The Planck 2018 measurements of the cosmic microwave background anisotropy favour a spatially closed universe at more than 2σ confidence level. We use model-independent methods to study the issue of cosmic curvature. The method reconstructs the Hubble parameter H(z) from cosmic chronometers d…
Radio spectral properties of star-forming galaxies in the MIGHTEE-COSMOS field and their impact on the far-infrared-radio correlation
Daddi, E.; Smail, Ian; Marchetti, L. +17 more
We study the radio spectral properties of 2094 star-forming galaxies (SFGs) by combining our early science data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey with VLA, GMRT radio data, and rich ancillary data in the COSMOS field. These SFGs are selected at VLA 3 GHz, and their flux densities from MeerKAT 1.3 …
Gaia pulsars and where to find them
Antoniadis, John
While the majority of massive stars have a stellar companion, most pulsars appear to be isolated. Taken at face value, this suggests that most massive binaries break apart due to strong natal kicks received in supernova explosions. However, the observed binary fraction can still be subject to strong selection effects, as monitoring of newly discov…
Revealing the relation between black hole growth and host-galaxy compactness among star-forming galaxies
Brandt, W. N.; Xue, Y. Q.; Luo, B. +8 more
Recent studies show that a universal relation between black hole (BH) growth and stellar mass (M⋆) or star formation rate (SFR) is an oversimplification of BH-galaxy coevolution, and that morphological and structural properties of host galaxies must also be considered. Particularly, a possible connection between BH growth and host-galax…