Search Publications
Linking chromospheric activity and magnetic field properties for late-type dwarf stars
Petit, P.; Vidotto, A. A.; Jeffers, S. V. +9 more
Spectropolarimetric data allow for simultaneous monitoring of stellar chromospheric $\log {R^{\prime }_{\rm {HK}}}$ activity and the surface-averaged longitudinal magnetic field, Bl, giving the opportunity to probe the relationship between large-scale stellar magnetic fields and chromospheric manifestations of magnetism. We present $\lo…
Deriving ages and horizontal branch properties of integrated stellar populations
Conroy, Charlie; Cabrera-Ziri, Ivan
A major source of uncertainty in the age determination of old (~10 Gyr) integrated stellar populations is the presence of hot horizontal branch (HB) stars. Here, we describe a simple approach to tackle this problem, and show the performance of this technique that simultaneously models the age, abundances, and HB properties of integrated stellar po…
Seismic modelling of a very young SPB star - KIC 8264293
Walczak, Przemysław; Moździerski, Dawid; Daszyńska-Daszkiewicz, Jadwiga +1 more
KIC 8264293 is a fast-rotating B-type pulsator observed by Kepler satellite. Its photometric variability is mainly due to pulsations in high-order g modes. Besides, we detected a weak Hα emission. Thus, the second source of variability is the fluctuation in a disc around the star. The pulsational spectrum of KIC 8264293 reveals a frequency groupin…
LRG-BEASTS: Sodium absorption and Rayleigh scattering in the atmosphere of WASP-94A b using NTT/EFOSC2
Kirk, J.; Louden, T.; Wheatley, P. J. +3 more
We present an optical transmission spectrum for WASP-94A b, the first atmospheric characterization of this highly-inflated hot Jupiter. The planet has a reported radius of $1.72^{+0.06}_{-0.05}$ RJup, a mass of only $0.456^{+0.032}_{-0.036}$ MJup, and an equilibrium temperature of 1508 ± 75 K. We observed the planet transit s…
Systematic Korea Microlensing Telescope Network planetary anomaly search - III. One wide-orbit planet and two stellar binaries
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +36 more
Only a few wide-orbit planets around old stars have been detected, which limits our statistical understanding of this planet population. Following the systematic search for planetary anomalies in microlensing events found by the Korea Microlensing Telescope Network, we present the discovery and analysis of three events that were initially thought …
Observations of the initial formation and evolution of spiral galaxies at 1 < z < 3 in the CANDELS fields
Conselice, Christopher J.; Simmons, Brooke; Masters, Karen +4 more
Many aspects concerning the formation of spiral and disc galaxies remain unresolved, despite their discovery and detailed study over the past 150 yr. As such, we present the results of an observational search for proto-spiral galaxies and their earliest formation, including the discovery of a significant population of spiral-like and clumpy galaxi…
Dust distributions in the magellanic clouds
Chen, B. -Q.; Yang, M.; Gao, J. +3 more
We present high-resolution maps of the dust reddening in the Magellanic Clouds (MCs). The maps cover the Large and Small Magellanic Cloud (LMC and SMC) area and have a spatial angular resolution between ~26 arcsec and 55 arcmin. Based on the data from the optical and near-infrared (IR) photometric surveys, including the Gaia Survey, the SkyMapper …
Where outflows meet inflows: gas kinematics in SSA22 Ly α blob 2 decoded by advanced radiative transfer modelling
Steidel, Charles C.; Gronke, Max; Li, Zhihui +2 more
We present new spectroscopic observations of Ly α (Ly α) Blob 2 (z ~ 3.1). We observed extended Ly α emission in three distinct regions, where the highest Ly α surface brightness (SB) centre is far away from the known continuum sources. We searched through the MOSFIRE slits that cover the high Ly α SB regions, but were unable to detect any signifi…
Do AGN triggering mechanisms vary with radio power? - II. The importance of mergers as a function of radio power and optical luminosity
Tadhunter, C. N.; Ramos Almeida, C.; Pierce, J. C. S. +7 more
Investigation of the triggering mechanisms of radio active galactic nuclei (radio AGN) is important for improving our general understanding of galaxy evolution. In the first paper in this series, detailed morphological analysis of high-excitation radio galaxies (HERGs) with intermediate radio powers suggested that the importance of triggering via …
A new reference catalogue for the very metal-poor Universe: +150 OB stars in Sextans A
Herrero, A.; Castro, N.; Najarro, F. +3 more
Local Group (LG) very metal-poor massive stars are the best proxy for the First Stars of the Universe and fundamental to modelling the evolution of early galaxies. These stars may follow new evolutionary pathways restricted to very low metallicities, such as chemically homogeneous evolution (CHE). However, given the great distance leap needed to r…