Search Publications
A fast-cadenced search for gamma-ray burst orphan afterglows with the Deeper, Wider, Faster programme
Auchettl, Katie; Allen, Rebecca; Andreoni, Igor +11 more
The relativistic outflows that produce long gamma-ray bursts (LGRBs) can be described by a structured jet model where prompt $\gamma$-ray emission is restricted to a narrow region in the jet's core. Viewing the jet off-axis from the core, a population of afterglows without an associated GRB detection can be predicted. In this work, we conduct an a…
The R-Process Alliance: detailed chemical composition of an r-process enhanced star with UV and optical spectroscopy
Beers, Timothy C.; Placco, Vinicius M.; Holmbeck, Erika M. +8 more
We present a detailed chemical-abundance analysis of a highly r-process-enhanced (RPE) star, 2MASS J00512646-1053170, using high-resolution spectroscopic observations with Hubble Space Telescope/STIS in the UV and Magellan/MIKE in the optical. We determined abundances for 41 elements in total, including 23 r-process elements and rarely probed spec…
Obscured star formation in clusters at z = 1.6-2.0: massive galaxy formation and the reversal of the star formation-density relation
Smail, Ian
Clusters of galaxies at z $\mathrel {\gtrsim }$ 1 are expected to be increasingly active sites of star formation. To test this, an 850 $\mu$m survey was undertaken of eight clusters at z = 1.6-2.0 using SCUBA-2 on the James Clerk Maxwell Telescope. Mid-infrared properties were used to identify 53 probable counterparts to 45 SCUBA-2 sources with co…
Uncovering the first-infall history of the LMC through its dynamical impact in the Milky Way halo
Tian, Hao; Ting, Yuan-Sen; Chang, Jiang +2 more
The gravitational interactions between the LMC and the Milky Way cause dynamical perturbations in the MW halo, leading to biased distributions of stellar density and kinematics. We run 50 high-resolution N-body simulations exploring varying masses and halo shapes of the MW and LMC to study the evolution of LMC-induced perturbations. By measuring m…
The first analysis of three long-period low mass-ratio contact binaries
Wang, Xi; Guo, Ya-Ni; Li, Kai +9 more
The photometric and spectroscopic studies of three contact binaries, ASASSN-V J052036.28+144711.0, ASASSN-V J064846.22+241709.9, and ASASSN-V J073441.02+555833.0 were performed for the first time. The periods of all the three targets are longer than 0.5 d, and we discovered that their mass ratios are all smaller than 0.25. So, they are long-period…
Understanding the relative importance of magnetic field, gravity, and turbulence in star formation at the hub of the giant molecular cloud G148.24+00.41
Wang, Jia-Wei; Eswaraiah, Chakali; Zavagno, A. +10 more
The relative importance of magnetic fields, turbulence, and gravity in the early phases of star formation is still not well understood. We report the first high-resolution dust polarization observations at 850 $\mu$m around the most massive clump, located at the hub of the Giant Molecular Cloud G148.24+00.41, using SCUBA-2/POL-2 at the James Clerk…
On an apparent dearth of recurrent nova super-remnants in the Local Group
Darnley, M. J.; Shara, M. M.; Healy-Kalesh, M. W.
The Andromeda Galaxy is home to the annually erupting recurrent nova (RN) M 31N 2008-12a (12a); the first nova found to host a nova super-remnant (NSR). An NSR is an immense structure surrounding a RN, created from many millions of eruptions sweeping up material in the local environment to form a shell tens of parsecs across. Theory has demonstrat…
A simple method to measure νmax for asteroseismology: application to 16 000 oscillating Kepler red giants
Li, Yaguang; Huber, Daniel; Bedding, Timothy R. +4 more
The importance of νmax (the frequency of maximum oscillation power) for asteroseismology has been demonstrated widely in the previous decade, especially for red giants. With the large amount of photometric data from CoRoT (Convection, Rotation, and planetary Transits), Kepler, and Transiting Exoplanet Survey Satellite, several automated…
Exoplanet transit spectroscopy with JWST NIRSpec: diagnostics and homogeneous case study of WASP-39 b
Madhusudhan, Nikku; Constantinou, Savvas; Sarkar, Subhajit +1 more
The JWST has ushered in a new era of exoplanet transit spectroscopy. Among the JWST instruments, the Near-Infrared Spectrograph (NIRSpec) has the most extensive set of configurations for exoplanet time-series observations. The NIRSpec Prism and G395H grating represent two extremes in NIRSpec instrument modes, with the Prism spanning a wider spectr…
A strontium-rich ultra-metal-poor star in the Atari disc component
Frebel, Anna; Mardini, Mohammad K.; Chiti, Anirudh
We report on the discovery of the first ultra-metal-poor (UMP) star 2MASS J20500194-6613298 (J2050-6613; [Fe/H] = -4.05) selected from the Gaia BP/RP spectral catalogue that belongs to the ancient Atari disc component. We obtained a high-resolution spectrum for the star with the MIKE spectrograph on the Magellan-Clay telescope. J2050-6613 displays…