Search Publications
The PAU Survey: Photometric redshifts using transfer learning from simulations
Carretero, J.; Castander, F. J.; Gaztanaga, E. +15 more
In this paper, we introduce the DEEPZ deep learning photometric redshift (photo-z) code. As a test case, we apply the code to the PAU survey (PAUS) data in the COSMOS field. DEEPZ reduces the σ68 scatter statistic by 50 per cent at iAB = 22.5 compared to existing algorithms. This improvement is achieved through various method…
New and improved rotational periods of magnetic CP stars from ASAS-3, KELT, and MASCARA data
Paunzen, Ernst; Hümmerich, Stefan; Bernhard, Klaus
Magnetic chemically peculiar (mCP) stars allow the investigation of such diverse phenomena as atomic diffusion, magnetic fields, and stellar rotation. The aim of the present investigation is to enhance our knowledge of the rotational properties of mCP stars by increasing the sample of objects with accurately determined rotational periods. To this …
Precise astrometry and diameters of asteroids from occultations - a data set of observations and their interpretation
Herald, David; Gault, David; Anderson, Robert +10 more
Occultations of stars by asteroids have been observed since 1961, increasing from a very small number to now over 500 annually. We have created and regularly maintain a growing data set of more than 5000 observed asteroidal occultations. The data set includes the raw observations, astrometry at the 1 mas level based on centre of mass or figure (no…
A SkyMapper view of the Large Magellanic Cloud: the dynamics of stellar populations
Lewis, Geraint F.; Ibata, Rodrigo A.; Mackey, Dougal +2 more
We present the first SkyMapper stellar population analysis of the Large Magellanic Cloud (hereafter LMC), including the identification of 3578 candidate Carbon Stars through their extremely red g - r colours. Coupled with Gaia astrometry, we analyse the distribution and kinematics of this Carbon Star population, finding the LMC to be centred at (R…
Blue straggler populations of seven open clusters with Gaia DR2
Vaidya, Kaushar; Rao, Khushboo K.; Agarwal, Manan +1 more
Blue straggler stars (BSS) are well studied in globular clusters but their systematic study with secure membership determination is lacking in open clusters. We use Gaia DR2 data to determine accurate stellar membership for four intermediate-age open clusters, namely Melotte 66, NGC 2158, NGC 2506, and NGC 6819, and three old open clusters, namely…
Survey of planetesimal belts with ALMA: gas detected around the Sun-like star HD 129590
Kral, Quentin; Wyatt, Mark C.; Kennedy, Grant M. +2 more
Gas detection around main-sequence stars is becoming more common with around 20 systems showing the presence of CO. However, more detections are needed, especially around later spectral type stars to better understand the origin of this gas and refine our models. To do so, we carried out a survey of 10 stars with predicted high likelihoods of seco…
Recipes for bolometric corrections and Gaia luminosities of B-type stars: application to an asteroseismic sample
Aerts, Conny; Escorza, Ana; Pedersen, May G. +1 more
We provide three statistical model prescriptions for the bolometric corrections appropriate for B-type stars as a function of (I) Teff, (II) Teff and log g, and (III)Teff, log g and [M/H]. These statistical models have been calculated for 27 different filters, including those of the Gaia space mission, and were der…
The SUrvey for Pulsars and Extragalactic Radio Bursts - IV. Discovery and polarimetry of a 12.1-s radio pulsar
Ray, P. S.; Kramer, M.; Johnston, S. +19 more
We report the discovery of PSR J2251-3711, a radio pulsar with a spin period of 12.1 s, the second longest currently known. Its timing parameters imply a characteristic age of 15 Myr, a surface magnetic field of 1.3 × 1013 G, and a spin-down luminosity of 2.9 × 1029 erg s-1. Its dispersion measure of 12.12(1) pc cm…
Core-collapse supernovae in binaries as the origin of galactic hyper-runaway stars
Rossi, E. M.; Renzo, M.; Evans, F. A.
Several stars detected moving at velocities near to or exceeding the Galactic escape speed likely originated in the Milky Way disc. We quantitatively explore the 'binary supernova scenario' hypothesis, wherein these 'hyper-runaway' stars are ejected at large peculiar velocities when their close, massive binary companions undergo a core-collapse su…
MKT J170456.2-482100: the first transient discovered by MeerKAT
Heywood, I.; Wijers, R. A. M. J.; Woudt, P. A. +19 more
We report the discovery of the first transient with MeerKAT, MKT J170456.2-482100, discovered in ThunderKAT images of the low-mass X-ray binary GX339-4. MKT J170456.2-482100 is variable in the radio, reaching a maximum flux density of 0.71± 0.11 mJy on 2019 October 12, and is undetected in 15 out of 48 ThunderKAT epochs. MKT J170456.2-482100 is co…