Search Publications
Resolving structure of the disc around HD100546 at 7 mm with ATCA
Wilner, D. J.; van Dishoeck, E. F.; Pinilla, P. +7 more
There is much evidence that planet formation is occurring in the disc around the Herbig Be star HD100546. To learn more about the processes occurring in this disc, we conducted high-resolution imaging at 43/45 GHz with the Australia Telescope Compact Array. Multiple array configurations were used, providing a best spatial resolution of ∼0.15 arcse…
A treatment procedure for VLT/SINFONI data cubes: application to NGC 5643
Ricci, T. V.; Steiner, J. E.; May, D. +3 more
In this second paper of a series, we present a treatment procedure for data cubes obtained with the Spectrograph for Integral Field Observations in the Near Infrared of the Very Large Telescope. We verified that the treatment procedure improves significantly the quality of the images of the data cubes, allowing a more detailed analysis. The images…
Optical polarization map of the Polaris Flare with RoboPol
Pearson, T. J.; Papadakis, I.; Blinov, D. +26 more
The stages before the formation of stars in molecular clouds are poorly understood. Insights can be gained by studying the properties of quiescent clouds, such as their magnetic field structure. The plane-of-the-sky orientation of the field can be traced by polarized starlight. We present the first extended, wide-field (∼10 deg2) map of…
SN Hunt 248: a super-Eddington outburst from a massive cool hypergiant
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Smith, Nathan +8 more
We present observations of SN Hunt 248, a new supernova (SN) impostor in NGC 5806, which began a multistage outburst in 2014 May. The `2014a' discovery brightening exhibited an absolute magnitude of M ≈ -12 and the spectral characteristics of a cool, dense outflow, including P Cygni lines of Fe II, H I, and Na I, and line blanketing from metals. T…
Spectroscopic constraints on CH3OH formation: CO mixed with CH3OH ices towards young stellar objects
Pontoppidan, K. M.; Blake, G. A.; Boogert, A. C. A. +3 more
The prominent infrared absorption band of solid CO - commonly observed towards young stellar objects (YSOs) - consists of three empirically determined components. The broad `red component' (2136 cm-1, 4.681 µm) is generally attributed to solid CO mixed in a hydrogen-bonded environment. Usually, CO embedded in the abundantly presen…
A new isolated dSph galaxy near the Local Group
Rizzi, L.; Karachentsev, I. D.; Makarova, L. N. +2 more
Observations of the highly isolated dwarf spheroidal galaxy KKs 3 = [KK2000] 03 with the Hubble Space Telescope Advanced Camera for Surveys are presented. We measured the galaxy distance of 2.12 ± 0.07 Mpc using the tip of red giant branch method. The total blue absolute magnitude of the galaxy is estimated as MB = -10.8 mag. We briefly…
X-ray bright active galactic nuclei in massive galaxy clusters - III. New insights into the triggering mechanisms of cluster AGN
Brandt, W. N.; von der Linden, A.; Xue, Y. Q. +6 more
We present the results of a new analysis of the X-ray selected active galactic nuclei (AGN) population residing in and behind 135 of the most massive galaxy clusters in the redshift range of 0.2 < z < 0.9 observed with Chandra. With a sample of more than 11 000 X-ray point sources, we are able to measure, for the first time, evidence for evo…
Predicting dust extinction properties of star-forming galaxies from Hα/UV ratio
Yamamura, Issei; Takita, Satoshi; Koyama, Yusei +8 more
Using star-forming galaxies sample in the nearby Universe (0.02 < z < 0.10) selected from the Sloan Digital Sky Survey (DR7) and Galaxy Evolution Explorer all-sky survey (GR5), we present a new empirical calibration for predicting dust extinction of galaxies from the Hα-to-FUV flux ratio. We find that the Hα dust extinction (AHα) …
Fine structure above a light bridge in the transition region and corona
Bharti, L.
We present the results of multiwavelength, co-spatial and near co-temporal observations of jets above a sunspot light bridge (LB). The data were obtained with the Solar Optical Telescope on board Hinode, the Interface Region Spectrograph (IRIS) and the Atmospheric Imaging Assembly (AIA) on the Solar Dynamic Observatory. Most of the jets in the Ca …
LOSS's first supernova? New limits on the `impostor' SN 1997bs
Kochanek, C. S.; Adams, Scott M.
We present new, late-time Hubble Space Telescope and Spitzer Space Telescope observations of the archetypal supernova (SN) impostor SN 1997bs. We show that SN 1997bs remains much fainter than its progenitor, posing a challenge for the canonical picture of late-time obscuration by dust forming in a shell ejected during the transient. The possibilit…