Search Publications
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…
Herschel spectroscopy of massive young stellar objects in the Magellanic Clouds
Lebouteiller, V.; Filipović, M. D.; Cormier, D. +11 more
We present Herschel Space Observatory Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver Fourier Transform Spectrometer (SPIRE FTS) spectroscopy of a sample of 20 massive Young Stellar Objects (YSOs) in the Large and Small Magellanic Clouds (LMC and SMC). We analyse the brightest far-infrared (far-IR) …
Stellar streams around the Magellanic Clouds in 4D
Belokurov, V.; Koposov, S. E.; Catelan, M. +7 more
We carried out a spectroscopic follow-up programme of the four new stellar stream candidates detected by Belokurov & Koposov in the outskirts of the Large Magellanic Cloud (LMC) using FORS2 (VLT). The medium-resolution spectra were used to measure the line-of-sight velocities, estimate stellar metallicities, and classify stars into Blue Horizo…
Long-term soft and hard X-ray investigation of the colliding wind WN+O binary WR 25
Pandey, J. C.; De Becker, M.; Arora, Bharti
We investigated the long-term behaviour in X-rays of the colliding wind binary WR 25, using archival data obtained with Suzaku, Swift, XMM-Newton, and NuSTAR spanning over ∼16 yr. Our analysis reveals phase-locked variations repeating consistently over many consecutive orbits, in agreement with an X-ray emission fully explained by thermal emission…