Search Publications
The population of hot subdwarf stars studied with Gaia. II. The Gaia DR2 catalogue of hot subluminous stars
Geier, S.; Marsh, T. R.; Raddi, R. +1 more
Based on data from the ESA Gaia Data Release 2 (DR2) and several ground-based, multi-band photometry surveys we have compiled an all-sky catalogue of 39 800 hot subluminous star candidates selected in Gaia DR2 by means of colour, absolute magnitude, and reduced proper motion cuts. We expect the majority of the candidates to be hot subdwarf stars o…
New Insights on Lyα and Lyman Continuum Radiative Transfer in the Greenest Peas
Scarlata, Claudia; Jaskot, Anne E.; Dowd, Tara +2 more
As some of the only Lyman continuum (LyC) emitters at z ∼ 0, Green Pea (GP) galaxies are possible analogs of the sources that reionized the universe. We present HST COS spectra of 13 of the most highly ionized GPs, with [O III]/[O II] = 6-35, and investigate correlations between Lyα, galaxy properties, and low-ionization UV lines. Galaxies with hi…
Identification of the long stellar stream of the prototypical massive globular cluster ω Centauri
Bianchini, Paolo; Martin, Nicolas; Malhan, Khyati +2 more
Omega Centauri (ω Cen) is the Milky Way's most massive globular cluster, and has long been suspected of being the remnant core of an accreted dwarf galaxy. If this scenario is correct, ω Cen should be tidally limited and tidal debris should be spread along its orbit. Here we use N-body simulations to show that the recently discovered `Fimbulthul' …
Is every strong lens model unhappy in its own way? Uniform modelling of a sample of 13 quadruply+ imaged quasars
Smith, M.; Abbott, T. M. C.; Allam, S. +70 more
Strong-gravitational lens systems with quadruply imaged quasars (quads) are unique probes to address several fundamental problems in cosmology and astrophysics. Although they are intrinsically very rare, ongoing and planned wide-field deep-sky surveys are set to discover thousands of such systems in the next decade. It is thus paramount to devise …
The VANDELS survey: the stellar metallicities of star-forming galaxies at 2.5 < z < 5.0
Cimatti, A.; Cullen, F.; McLure, R. J. +24 more
We present the results of a study utilizing ultradeep, rest-frame UV, spectroscopy to quantify the relationship between stellar mass and stellar metallicity for 681 star-forming galaxies at 2.5 < z < 5.0 (<z> = 3.5 ± 0.6) drawn from the VANDELS survey. Via a comparison with high-resolution stellar population synthesis models, we determ…
VLT/FLAMES high-resolution chemical abundances in Sculptor: a textbook dwarf spheroidal galaxy
Spite, M.; Skúladóttir, Á.; Jablonka, P. +12 more
We present detailed chemical abundances for 99 red-giant branch stars in the centre of the Sculptor dwarf spheroidal galaxy, which have been obtained from high-resolution VLT/FLAMES spectroscopy. The abundances of Li, Na, α-elements (O, Mg, Si, Ca Ti), iron-peak elements (Sc, Cr, Fe, Co, Ni, Zn), and r- and s-process elements (Ba, La, Nd, Eu) were…
First Gaia Dynamics of the Andromeda System: DR2 Proper Motions, Orbits, and Rotation of M31 and M33
van der Marel, Roeland P.; Watkins, Laura L.; Fardal, Mark A. +5 more
The 3D velocities of M31 and M33 are important for understanding the evolution and cosmological context of the Local Group. Their most massive stars are detected by Gaia, and we use Data Release 2 (DR2) to determine the galaxy proper motions (PMs). We select galaxy members based on, e.g., parallax, PM, color-magnitude diagram location, and local s…
SDSS-IV MaStar: A Large and Comprehensive Empirical Stellar Spectral Library—First Release
Zhao, Gang; Bizyaev, Dmitry; Kinemuchi, Karen +45 more
We present the first release of the MaNGA Stellar Library (MaStar), which is a large, well-calibrated, high-quality empirical library covering the wavelength range 3622-10354 Å at a resolving power of R ∼ 1800. The spectra were obtained using the same instrument as used by the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) project, by…
Cosmological Constraints from Multiple Probes in the Dark Energy Survey
Bacon, D.; Bechtol, K.; Challis, P. +161 more
The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy cluster…
SILVERRUSH. VIII. Spectroscopic Identifications of Early Large-scale Structures with Protoclusters over 200 Mpc at z ∼ 6-7: Strong Associations of Dusty Star-forming Galaxies
Ono, Yoshiaki; Ouchi, Masami; Goto, Tomotsugu +32 more
We have obtained three-dimensional maps of the universe in ∼200 × 200 × 80 comoving Mpc3 (cMpc3) volumes each at z = 5.7 and 6.6 based on a spectroscopic sample of 179 galaxies that achieves ≳80% completeness down to the Lyα luminosity of {log}({L}Lyα }/[{erg} {{{s}}}-1])=43.0, based on our Keck and Gemi…