Search Publications
Testing the role of environmental effects on the initial mass function of low-mass stars
Jose, Jessy; Samal, Manash R.; Moraux, Estelle +3 more
In the star-formation process, the vital impact of environmental factors such as feedback from massive stars and stellar density on the form of the initial mass function (IMF) at the low-mass end is yet to be understood. Hence a systematic highly sensitive observational analysis of a sample of regions under diverse environmental conditions is esse…
Improving sampling and calibration of gamma-ray bursts as distance indicators
Montiel, Ariadna; Cabrera, J. I.; Hidalgo, Juan Carlos
We present a sample of 74 gamma-ray bursts (GRBs) from the Fermi-GBM catalogue for which we compute the distance moduli and use them to constrain effective dark energy models. To overcome the circularity problem affecting GRBs as distance indicators, we calibrate the Amati relation of our sample with a cosmology-independent technique. Specifically…
The KBSS-KCWI survey: the connection between extended Ly α haloes and galaxy azimuthal angle at z 2-3
Erb, Dawn K.; Shapley, Alice E.; Steidel, Charles C. +9 more
We present the first statistical analysis of kinematically resolved, spatially extended $\rm Ly\alpha$ emission around z = 2-3 galaxies in the Keck Baryonic Structure Survey (KBSS) using the Keck Cosmic Web Imager (KCWI). Our sample of 59 star-forming galaxies (zmed = 2.29) comprises the subset with typical KCWI integration times of ~5 …
Ionized emission and absorption in a large sample of ultraluminous X-ray sources
Valtchanov, I.; Guainazzi, M.; Fabian, A. C. +6 more
Most ultraluminous X-ray sources (ULXs) are thought to be powered by super-Eddington accretion on to stellar-mass compact objects. Accretors in this extreme regime are naturally expected to ionize copious amounts of plasma in their vicinity and launch powerful radiation-driven outflows from their discs. High spectral resolution X-ray observations …
The Pristine survey XIII: uncovering the very metal-poor tail of the thin disc
Sestito, Federico; Navarro, Julio F.; Malhan, Khyati +9 more
We evaluate the rotational velocity of stars observed by the Pristine survey towards the Galactic anticentre spanning a wide range of metallicities from the extremely metal-poor regime ([Fe/H] < -3) to nearly solar metallicity. In the Galactic anticentre direction, the rotational velocity (Vϕ) is similar to the tangential velocity in…
Mass calibration of distant SPT galaxy clusters through expanded weak-lensing follow-up observations with HST, VLT, & Gemini-South
Schrabback, T.; Schirmer, M.; Sommer, M. +18 more
Expanding from previous work, we present weak-lensing (WL) measurements for a total sample of 30 distant (zmedian = 0.93) massive galaxy clusters from the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) Survey, measuring galaxy shapes in Hubble Space Telescope (HST) Advanced Camera for Surveys images. We remove cluster members and pref…
GAMA/DEVILS: constraining the cosmic star formation history from improved measurements of the 0.3-2.2 µm extragalactic background light
Obreschkow, Danail; Hopkins, Andrew M.; Driver, Simon P. +12 more
We present a revised measurement of the optical extragalactic background light (EBL), based on the contribution of resolved galaxies to the integrated galaxy light (IGL). The cosmic optical background radiation (COB), encodes the light generated by star formation, and provides a wealth of information about the cosmic star formation history (CSFH).…
The evolution of the size-mass relation at z = 1-3 derived from the complete Hubble Frontier Fields data set
Treu, Tommaso; Bradač, Maruša; Birrer, Simon +3 more
We measure the size-mass relation and its evolution between redshifts 1 < z < 3, using galaxies lensed by six foreground Hubble Frontier Fields clusters. The power afforded by strong gravitation lensing allows us to observe galaxies with higher angular resolution beyond current facilities. We select a stellar mass limited sample and divide t…
Gemini/GMOS optical transmission spectroscopy of WASP-121b: signs of variability in an ultra-hot Jupiter?
Nikolov, Nikolay; de Mooij, Ernst J. W.; Gibson, Neale P. +5 more
We present ground-based, spectroscopic observations of two transits of the ultra-hot Jupiter WASP-121b covering the wavelength range ≈500-950 nm using Gemini/GMOS. We use a Gaussian process framework to model instrumental systematics in the light curves, and also demonstrate the use of the more generalized Student's-T process to verify our results…
The kinematics of globular cluster populations in the E-MOSAICS simulations and their implications for the assembly history of the Milky Way
Kruijssen, J. M. Diederik; Trujillo-Gomez, Sebastian; Crain, Robert A. +5 more
We present a detailed comparison of the Milky Way (MW) globular cluster (GC) kinematics with the 25 MW-mass cosmological simulations from the E-MOSAICS project. While the MW falls within the kinematic distribution of GCs spanned by the simulations, the relative kinematics of its metal-rich ( $[\rm {Fe}/\rm {H}] \gt -1.2$ ) versus metal-poor ( $[\r…