Search Publications
The GALAH Survey: lithium-strong KM dwarfs
Zwitter, T.; Buder, S.; Casagrande, L. +10 more
Identifying and characterizing young stars in the Solar neighbourhood is essential to find and describe planets in the early stages of their evolution. This work seeks to identify nearby young stars showing a lithium 6708 Å absorption line in the GALAH survey. A robust, data-driven approach is used to search for corresponding templates in the pool…
C IV absorbers tracing cool gas in dense galaxy group/cluster environments
Charlton, Jane C.; Muzahid, Sowgat; Narayanan, Anand +3 more
We present analysis on three intervening H I-C IV absorption systems tracing gas within galaxy group/cluster environments, identified in the HST/COS far-UV spectra of the background quasars PG 1148 + 549 (zabs = 0.003 46), SBS 1122 + 594 (zabs = 0.004 02), and RXJ 1230.8 + 0115 (zabs = 0.005 74). The ionization mod…
Hemispheric asymmetry in meridional flow and the sunspot cycle
Antia, H. M.; Nandy, Dibyendu; Lekshmi, B.
Magnetohydrodynamic dynamo modelling shows that the large-scale solar meridional plasma flow plays an important role in governing the dynamics of the sunspot cycle. Observations indicate that meridional flow velocities at each solar latitude and depth vary over time and are asymmetric across the equator. Here, using helioseismic observations we ex…
A comparison between the two lobes of comet 67P/Churyumov-Gerasimenko based on D/H ratios in H2O measured with the Rosetta/ROSINA DFMS
De Keyser, Johan; Hansen, Kenneth C.; Gombosi, Tamas I. +13 more
The nucleus of the Jupiter-family comet 67P/Churyumov-Gerasimenko was discovered to be bi-lobate in shape when the European Space Agency spacecraft Rosetta first approached it in 2014 July. The bi-lobate structure of the cometary nucleus has led to much discussion regarding the possible manner of its formation and on how the composition of each lo…
UVIT-HST-GAIA view of NGC 288: a census of the hot stellar population and its properties from UV
Rao, N. Kameswara; Stetson, Peter B.; Sahu, Snehalata +2 more
A complete census of the blue horizontal branch (BHB) and blue straggler star (BSS) population within a 10' radius from the centre of the globular cluster NGC 288 is presented, based on images from the Ultraviolet Imaging Telescope (UVIT). The UV and UV-optical colour-magnitude diagrams (CMDs) are constructed by combining the UVIT, HST-ACS and gro…
The enigmatic binary system HD 5980
Hillier, D. John; Morrell, Nidia; Nazé, Yaël +3 more
The Small Magellanic Cloud multiple system HD 5980 contains a luminous blue variable (LBV) that underwent a major eruption in 1994, and whose current spectrum is that of a hydrogen-rich Wolf-Rayet (WR) star. Since the eruption, the wind mass-loss rate has been declining while wind speeds have been steadily increasing. Observations obtained in 2014…
On the triple-star origin of the planetary nebula Sh 2-71
Corradi, Romano L. M.; Jones, David; Pejcha, Ondřej
Recent studies have indicated that triple-star systems may play a role in the formation of an appreciable number of planetary nebulae, however, only one triple central star is known to date (and that system is likely too wide to have had much influence on the evolution of its component stars). Here, we consider the possibility that Sh 2-71 was for…
A systematic study of soft X-ray pulse profiles of magnetars in quiescence
Ho, Wynn C. G.; Hu, Chin-Ping; Ng, C. -Y.
Magnetars are neutron stars with extremely high surface magnetic fields. They show diverse X-ray pulse profiles in the quiescent state. We perform a systematic Fourier analysis of their soft X-ray pulse profiles. We find that most magnetars have a single-peaked profile and hence have low amplitudes of the second Fourier harmonics (A2). …
Deep ugrizY imaging and DEEP2/3 spectroscopy: a photometric redshift testbed for LSST and public release of data from the DEEP3 Galaxy Redshift Survey
Trump, Jonathan R.; Conselice, Christopher J.; Nandra, Kirpal +19 more
We present catalogues of calibrated photometry and spectroscopic redshifts in the Extended Groth Strip, intended for studies of photometric redshifts (photo-z's). The data includes ugriz photometry from Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) and Y-band photometry from the Subaru Suprime camera, as well as spectroscopic redshifts fro…
Revealing dust-obscured star formation in CLJ1449+0856, a cluster at z = 2
Papageorgiou, A.; Smith, M. W. L.; Eales, S. A. +2 more
We present SCUBA-2 450 and 850 µm data of the mature redshift 2 cluster CLJ1449. We combine this with archival Herschel data to explore the star-forming properties of CLJ1449. Using high-resolution Atacama Large Millimetre Array and Jansky Very Large Array data we identify potentially confused galaxies, and use the Bayesian inference tool XI…