Search Publications
Binary deviations from single object astrometry
Koposov, S. E.; Belokurov, Vasily; Penoyre, Zephyr +2 more
Most binaries are undetected. Astrometric reductions of a system using the assumption that the object moves like a single point mass can be biased by unresolved binary stars. The discrepancy between the centre of mass of the system (which moves like a point mass) and the centre of light (which is what we observe) introduces additional motion. We e…
X-ray detected AGN in SDSS dwarf galaxies
Birchall, Keir L.; Watson, M. G.; Aird, J.
In this work we present a robust quantification of X-ray selected AGN in local (z ≤ 0.25) dwarf galaxies (M_* ≤ 3 × 10^9 M_⊙ ). We define a parent sample of 4331 dwarf galaxies found within the footprint of both the MPA-JHU galaxy catalogue (based on SDSS DR8) and 3XMM DR7, performed a careful review of the data to remove misidentifications and pr…
The R136 star cluster dissected with Hubble Space Telescope/STIS - II. Physical properties of the most massive stars in R136
Vink, Jorick S.; Brands, Sarah A.; Langer, Norbert +11 more
We present an optical analysis of 55 members of R136, the central cluster in the Tarantula Nebula of the Large Magellanic Cloud. Our sample was observed with STIS aboard the Hubble Space Telescope, is complete down to about 40 M⊙, and includes seven very massive stars with masses over 100 M⊙. We performed a spectroscopic anal…
The KLEVER Survey: spatially resolved metallicity maps and gradients in a sample of 1.2 < z < 2.5 lensed galaxies
Maiolino, Roberto; Cresci, Giovanni; Pettini, Max +17 more
We present near-infrared observations of 42 gravitationally lensed galaxies obtained in the framework of the KMOS Lensed Emission Lines and VElocity Review (KLEVER) Survey, a programme aimed at investigating the spatially resolved properties of the ionized gas in 1.2 < z < 2.5 galaxies by means of a full coverage of the YJ, H, and K near-inf…
The chemical compositions of accreted and in situ galactic globular clusters according to SDSS/APOGEE
Majewski, Steven R.; Beers, Timothy C.; Horta, Danny +16 more
Studies of the kinematics and chemical compositions of Galactic globular clusters (GCs) enable the reconstruction of the history of star formation, chemical evolution, and mass assembly of the Galaxy. Using the latest data release (DR16) of the SDSS/APOGEE survey, we identify 3090 stars associated with 46 GCs. Using a previously defined kinematic …
Timing the earliest quenching events with a robust sample of massive quiescent galaxies at 2 < z < 5
Cimatti, A.; Cullen, F.; McLure, R. J. +19 more
We present a sample of 151 massive (M* > 1010 M⊙) quiescent galaxies at 2 < z < 5, based on a sophisticated Bayesian spectral energy distribution fitting analysis of the CANDELS UDS and GOODS-South fields. Our sample includes a robust sub-sample of 61 objects for which we confidently exclude low-redshift a…
The `red supergiant problem': the upper luminosity boundary of Type II supernova progenitors
Beasor, Emma R.; Davies, Ben
By comparing the properties of red supergiant (RSG) supernova (SN) progenitors to those of field RSGs, it has been claimed that there is an absence of progenitors with luminosities L above log (L/L⊙) > 5.2. This is in tension with the empirical upper luminosity limit of RSGs at log (L/L⊙) = 5.5, a result known as the `RSG …
The Galactic radial abundance gradients of C, N, O, Ne, S, Cl, and Ar from deep spectra of H II regions
Méndez-Delgado, J. E.; Arellano-Córdova, K. Z.; García-Rojas, J. +1 more
We present a reassessment of the radial abundance gradients of C, N, O, Ne, S, Cl, and Ar in the Milky Way using deep spectra of 33 H II regions gathered from the literature, covering Galactocentric distances from 6 to 17 kpc. The distances of the objects have been revised using Gaia parallaxes. We recalculate the physical conditions and ionic abu…
Spiral arms in the protoplanetary disc HD100453 detected with ALMA: evidence for binary-disc interaction and a vertical temperature gradient
Dominik, C.; Benisty, M.; Stolker, T. +7 more
Scattered light high-resolution imaging of the protoplanetary disc orbiting HD100453 shows two symmetric spiral arms, possibly launched by an external stellar companion. In this paper, we present new, sensitive high-resolution (∼30 mas) Band 7 ALMA observations of this source. This is the first source where we find counterparts in the sub-mm conti…
A physically motivated definition for the size of galaxies in an era of ultradeep imaging
Trujillo, Ignacio; Knapen, Johan H.; Chamba, Nushkia
Present-day multiwavelength deep imaging surveys allow to characterize the outskirts of galaxies with unprecedented precision. Taking advantage of this situation, we define a new physically motivated measurement of size for galaxies based on the expected location of the gas density threshold for star formation. Employing both theoretical and obser…