Search Publications
KIC 5950759: a high-amplitude δ Sct star with amplitude and frequency modulation near the terminal age main sequence
Bowman, D. M.; Smalley, B.; Tkachenko, A. +5 more
Among the intermediate mass pulsating stars known as δ Sct stars is a subset of high-amplitude and predominantly radial-mode pulsators known as high-amplitude δ Sct (HADS) stars. From more than 2000 δ Sct stars observed by the Kepler space mission, only two HADS stars were detected. We investigate the more perplexing of these two HADS stars, KIC 5…
Cross-correlation of Planck CMB lensing with DESI-like LRGs
White, Martin; Kitanidis, Ellie
Cross-correlations between the lensing of the cosmic microwave background (CMB) and other tracers of large-scale structure provide a unique way to reconstruct the growth of dark matter, break degeneracies between cosmology and galaxy physics, and test theories of modified gravity. We detect a cross-correlation between Dark Energy Spectroscopic Ins…
Local stellar kinematics and Oort constants from the LAMOST A-type stars
Wang, H. -F.; Huang, Y.; Chen, B. -Q. +3 more
We estimate the solar peculiar velocities and Oort constants using a sample of 5627 A-type stars with $d\lt 0.6\, \rm kpc$ and $|z|\lt 0.1\, \rm kpc$, selected from the LAMOST (Large Sky Area Multi-Object Fiber Spectroscopic Telescope) surveys. The radial and tangential velocities of these A-type stars are fitted by using a non-axisymmetric model.…
Detection of complex organic molecules in young starless core L1521E
Vasyunin, Anton; Launhardt, Ralf; Shirley, Yancy +1 more
Determining the level of chemical complexity within dense starless and gravitationally bound pre-stellar cores is crucial for constructing chemical models, which subsequently constrain the initial chemical conditions of star formation. We have searched for complex organic molecules (COMs) in the young starless core L1521E, and report the first cle…
Star formation history of the solar neighbourhood as told by Gaia
Alzate, Jairo A.; Bruzual, Gustavo; Díaz-González, Daniel J.
The Gaia data release 2 (DR2) catalogue is the best source of stellar astrometric and photometric data available today. The history of the Milky Way galaxy is written in stone in this data set. Parallaxes and photometry tell us where the stars are today, when were they formed, and with what chemical content, that is, their star formation history (…
High-resolution spectroscopic follow-up of the most metal-poor candidates from SkyMapper DR1.1
Schmidt, B. P.; Da Costa, G. S.; Marino, A. F. +13 more
We present chemical abundances for 21 elements (from Li to Eu) in 150 metal-poor Galactic stars spanning -4.1 < [Fe/H] < -2.1. The targets were selected from the SkyMapper survey and include 90 objects with [Fe/H] ≤ -3 of which some 15 have [Fe/H] ≤ -3.5. When combining the sample with our previous studies, we find that the metallicity distr…
Revisiting the dust destruction efficiency of supernovae
De Looze, I.; Gomez, H. L.; Barlow, M. J. +3 more
Dust destruction by supernovae is one of the main processes removing dust from the interstellar medium (ISM). Estimates of the efficiency of this process, both theoretical and observational, typically assume a shock propagating into a homogeneous medium, whereas the ISM possesses significant substructure in reality. We self-consistently model the …
Measuring the fine-structure constant on a white dwarf surface; a detailed analysis of Fe V absorption in G191-B2B
Barstow, M. A.; Webb, J. K.; Carswell, R. F. +12 more
The gravitational potential ϕ = GM/Rc2 at the surface of the white dwarf G191-B2B is 10 000 times stronger than that at the Earth's surface. Numerous photospheric absorption features are detected, making this a suitable environment to test theories in which the fundamental constants depend on gravity. We have measured the fine-structure…
Dissecting the stellar content of Leo I: a dwarf irregular caught in transition
Monelli, M.; Cassisi, S.; Gallart, C. +7 more
Leo I is considered one of the youngest dwarf spheroidals (dSph) in the Local Group. Its isolation, extended star formation history (SFH), and recent perigalacticon passage (∼1 Gyr ago) make Leo I one of the most interesting nearby stellar systems. Here, we analyse deep photometric Hubble Space Telescope data via colour-magnitude diagram fitting t…
The non-monotonic, strong metallicity dependence of the wide-binary fraction
Ting, Yuan-Sen; Wyse, Rosemary F. G.; Zakamska, Nadia L. +2 more
The metallicity dependence of the wide-binary fraction (WBF) IN stellar populations plays a critical role in resolving the open question of wide-binary formation. In this paper, we investigate the metallicity ([Fe/H]) and age dependence of the WBF (binary separations between 103 and 104 au) for field F and G dwarfs within 500…