Search Publications
A MeerKAT survey of nearby nova-like cataclysmic variables
Knigge, C.; Heywood, I.; Wijers, R. A. M. J. +17 more
We present the results of MeerKAT radio observations of 11 nearby nova-like cataclysmic variables (CVs). We have detected radio emission from IM Eri, RW Sex, V3885 Sgr, and V603 Aql. While RW Sex, V3885 Sgr, and V603 Aql had been previously detected, this is the first reported radio detection of IM Eri. Our observations have doubled the sample of …
Kinematical investigation of possible fast collimated outflows in twelve planetary nebulae
Chu, Y. -H.; Guerrero, M. A.; Toalá, J. A. +3 more
A significant fraction of planetary nebulae (PNe) exhibit collimated outflows, distinct narrow kinematical components with notable velocity shifts with respect to the main nebular shells typically associated with low-ionization compact knots and linear or precessing jet-like features. We present here a spatio-kinematical investigation of a sample …
Diffuse radio emission in the galaxy cluster SPT-CL J2031-4037: a steep-spectrum intermediate radio halo?
van Weeren, R. J.; Rapetti, David; Intema, H. T. +6 more
The advent of sensitive low-frequency radio observations has revealed a number of diffuse radio objects with peculiar properties that are challenging our understanding of the physics of the intracluster medium. Here, we report the discovery of a steep-spectrum radio halo surrounding the central brightest cluster galaxy (BCG) in the galaxy cluster …
CO in the C1 globule of the Helix nebula with ALMA
Avison, A.; Zijlstra, A.; Andriantsaralaza, M.
We present and analyse 12CO, 13CO, and C18O(2-1) ALMA observations of the C1 globule inside the Helix nebula in order to determine its physical properties. Our findings confirm the molecular nature of the globule with a multipeak structure. The 12CO line has a high optical depth τ ∼10. The derived 1…
A new look at Sco OB1 association with Gaia DR2
Costa, E.; Carraro, G.; Yalyalieva, L. +3 more
We present and discuss photometric optical data in the area of the OB association Sco OB1 covering about 1 deg2. UBVI photometry is employed in tandem with Gaia DR2 data to investigate the three-dimensional structure and the star formation history of the region. By combining parallaxes and proper motions, we identify seven physical grou…
CFHT MegaPrime/MegaCam u-band source catalogue of the AKARI North Ecliptic Pole Wide field
Hashimoto, Tetsuya; Goto, Tomotsugu; Kim, Seong Jin +10 more
The $AKARI$ infrared (IR) space telescope conducted two surveys (Deep and Wide) in the North Ecliptic Pole (NEP) field to find more than 100 000 IR sources using its infrared camera (IRC). IRC's nine filters, which cover wavebands from 2 to 24 µm continuously, make $AKARI$ unique in comparison with other IR observatories such as $Spitzer$ or…
A radiative transfer model for the spiral galaxy M33★
Tuffs, Richard J.; Popescu, Cristina C.; Grootes, Meiert +5 more
We present the first radiative transfer (RT) model of a non-edge-on disc galaxy in which the large-scale geometry of stars and dust is self-consistently derived through the fitting of multiwavelength imaging observations from the ultraviolet to the submm. To this end, we used the axisymmetric RT model of Popescu et al. and a new methodology for de…
Quasar Sightline and Galaxy Evolution (QSAGE) survey - II. Galaxy overdensities around UV luminous quasars at z = 1-2
Cullen, F.; Bower, R. G.; Tejos, N. +8 more
We demonstrate that the UV brightest quasars at z = 1-2 live in overdense environments. This is based on an analysis of deep Hubble Space Telescope WFC3 G141 grism spectroscopy of the galaxies along the lines-of-sight to UV luminous quasars in the redshift range z = 1-2. This constitutes some of the deepest grism spectroscopy performed by WFC3, wi…
The discovery of lambda Bootis stars - the Southern Survey II
Bedding, Timothy R.; Murphy, Simon J.; Gray, Richard O. +3 more
The λ Boo stars are chemically peculiar A-type stars whose abundance anomalies are associated with the accretion of metal-poor material. We searched for λ Boo stars in the Southern hemisphere in a targeted spectroscopic survey of metal-weak and emission-line stars. Obtaining spectra for 308 stars and classifying them on the MK system, we found or …
Chandra and XMM-Newton observations of A2256: cold fronts, merger shocks, and constraint on the IC emission
Rudnick, Lawrence; Finoguenov, Alexis; Clarke, Tracy E. +13 more
We present the results of deep Chandra and XMM-Newton observations of a complex merging galaxy cluster Abell 2256 (A2256) that hosts a spectacular radio relic (RR). The temperature and metallicity maps show clear evidence of a merger between the western subcluster (SC) and the primary cluster (PC). We detect five X-ray surface brightness edges. Th…