Search Publications
Revealing a ring-like cluster complex in a tidal tail of the starburst galaxy NGC 2146
Bastian, N.; Larsen, S. S.; Gallagher, J. S. +9 more
We report the discovery of a ring-like cluster complex in the starburst galaxy NGC 2146. The Ruby Ring, so named due to its appearance, shows a clear ring-like distribution of star clusters around a central object. It is located in one of the tidal streams that surround the galaxy. NGC 2146 is part of the Snapshot Hubble U-band Cluster Survey (SHU…
HST/WFPC2 imaging of the dwarf satellites And XI and And XIII: horizontal branch morphology and RR Lyraes
Sarajedini, A.; Yang, S. -C.
We present a study of the stellar populations in two faint M31 dwarf satellites, Andromeda XI and Andromeda XIII. Using archival images from the Wide Field Planetary Camera 2 onboard the Hubble Space Telescope, we characterize the horizontal branch (HB) morphologies and the RR Lyrae (RRL) populations of these two faint dwarf satellites. Our new te…
The gas-to-dust mass ratio of Centaurus A as seen by Herschel
Boquien, M.; Roussel, H.; Cooray, A. +20 more
We present photometry of the nearby galaxy NGC 5128 (Centaurus A) observed with the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on board the Herschel Space Observatory, at 70, 160, 250, 350 and 500 µm, as well as new CO J= 3-2 observations taken with the HARP-B instrume…
Recurrent dust formation by WR 48a on a 30-year time-scale
Marang, Fred; Whitelock, Patricia A.; Williams, Peredur M. +4 more
We present infrared photometry of the WC8 Wolf-Rayet system WR 48a observed with telescopes at the European Southern Observatory, the South African Astronomical Observatory and the Anglo Australian Telescope between 1982 and 2011, which show a slow decline in dust emission from the previously reported outburst in 1978-79 until about 1997, when sig…
Quantifying the universality of the stellar initial mass function in old star clusters
Sills, Alison; Sarajedini, Ata; de Marchi, Guido +4 more
We present a new technique to quantify cluster-to-cluster variations in the observed present-day stellar mass functions of a large sample of star clusters. Our method quantifies these differences as a function of both the stellar mass and the total cluster mass, and offers the advantage that it is insensitive to the precise functional form of the …
A multiwavelength study of evolved massive stars in the Galactic Centre
Morris, M. R.; Wang, Q. D.; Dong, H.
The central region of the Milky Way Galaxy provides a unique laboratory for a systematic, spatially resolved population study of evolved massive stars of various types in a relatively high-metallicity environment. We have conducted a multiwavelength data analysis of 180 such stars or candidates, most of which were drawn from a recent large-scale H…
The SLUGGS survey: globular cluster system kinematics and substructure in NGC 4365
Spitler, Lee R.; Forbes, Duncan A.; Romanowsky, Aaron J. +4 more
We present a kinematic analysis of the globular cluster (GC) system of the giant elliptical galaxy NGC 4365 and find several distinct kinematic substructures. This analysis is carried out using radial velocities for 269 GCs, obtained with the DEIMOS (DEep Imaging Multi-Object Spectrograph) instrument on the Keck II telescope as part of the SAGES L…
Near-infrared spectroscopy of gamma-ray burst host galaxies at z %≳ 1.5: insights into host galaxy dynamics and interpretations of afterglow absorption spectra
Chen, Hsiao-Wen
This paper presents near-infrared echellette spectra of faint galaxies in the fields around GRB 050820A at redshift z= 2.613 and GRB 060418 at z= 1.490. The spectroscopic data show that both gamma-ray bursts (GRBs) originate in a dynamic environment of interacting galaxies separated by <15 h-1 kpc in projected distance and |Δv| ≲ 60 …
Herschel-PACS observations of [O I]63 µm towards submillimetre galaxies at z ∼ 1
Ivison, R. J.; Menten, K. M.; Smail, Ian +22 more
We present Herschel-PACS spectroscopy of the [O I]63 µm far-infrared cooling line from a sample of six unlensed and spectroscopically confirmed 870 µm selected submillimetre (submm) galaxies (SMGs) at 1.1 < z < 1.6 from the LABOCA Extended Chandra Deep Field South (ECDFS) Submm Survey (LESS). This is the first survey of [O I]63 &…
Timing and broad-band spectroscopy of 1A 1118-61 with Suzaku
Maitra, Chandreyee; Paul, Biswajit; Naik, Sachindra
We present a timing and broad-band pulse-phase-resolved spectral analysis of the transient Be X-ray binary pulsar 1A 1118-61 observed during its outburst in 2009 January using Suzaku observations. The Suzaku observations were made twice, once at the peak of the outburst, and the other 13 d later at its declining phase. Pulse profiles from both obs…