Search Publications
Chemical abundances and radial velocities in the extremely metal-poor galaxy DDO 68
Tosi, M.; Bellazzini, M.; Cusano, F. +9 more
We present chemical abundances and radial velocities of six H II regions in the extremely metal-poor star-forming dwarf galaxy DDO 68. They are derived from deep spectra in the wavelength range 3500-10 000 Å, acquired with the Multi-Object Double Spectrograph at the Large Binocular Telescope (LBT). In the three regions where the [O III] λ4363 Å li…
A resonant pair of warm giant planets revealed by TESS
Torres, Guillermo; Nesvorný, David; Kipping, David +4 more
We present the discovery of a pair of transiting giant planets using four sectors of TESS photometry. TOI-216 is a 0.87 M⊙ dwarf orbited by two transiters with radii of 8.2 and 11.3 R⊕, and periods of 17.01 and 34.57 d, respectively. Anticorrelated TTVs are clearly evident indicating that the transiters orbit the same star an…
Probing cosmic dawn: modelling the assembly history, SEDs, and dust content of selected z ∼ 9 galaxies
Ellis, Richard S.; Laporte, Nicolas; Devriendt, Julien +2 more
The presence of spectroscopically confirmed Balmer breaks in galaxy spectral energy distributions (SEDs) at z > 9 provides one of the best probes of the assembly history of the first generations of stars in our Universe. Recent observations of the gravitationally lensed source, MACS 1149_JD1 (JD1), indicate that significant amounts of star form…
Quasar Sightline and Galaxy Evolution (QSAGE) survey - I. The galaxy environment of O VI absorbers up to z = 1.4 around PKS 0232-04
Cullen, F.; Bower, R. G.; Tejos, N. +8 more
We present the first results from a study of O VI absorption around galaxies at z < 1.44 using data from a near-infrared grism spectroscopic Hubble Space Telescope Large Programme, the Quasar Sightline and Galaxy Evolution (QSAGE) survey. QSAGE is the first grism galaxy survey to focus on the circumgalactic medium at z ∼ 1, providing a blind su…
Stellar binaries that survive supernovae
Kochanek, C. S.; Belczynski, K.; Auchettl, K.
The number of binaries containing black holes (BH) or neutron stars (NS) depends critically on the fraction of binaries that survive supernova (SN) explosions. We searched for surviving star plus remnant binaries in a sample of 49 supernova remnants (SNR) containing 23 previously identified compact remnants and three high-mass X-ray binaries (HMXB…
The H I velocity function: a test of cosmology or baryon physics?
Obreschkow, Danail; Lagos, Claudia del P.; Elahi, Pascal J. +3 more
Accurately predicting the shape of the H I velocity function (VF) of galaxies is regarded widely as a fundamental test of any viable dark matter model. Straightforward analyses of cosmological N-body simulations imply that the Λ cold dark matter (ΛCDM) model predicts an overabundance of low circular velocity galaxies when compared to observed H I …
Galaxy-Galaxy lensing in HSC: Validation tests and the impact of heterogeneous spectroscopic training sets
Sifón, Cristóbal; Leauthaud, Alexie; Eisenstein, Daniel J. +9 more
Although photometric redshifts (photo-z's) are crucial ingredients for current and upcoming large-scale surveys, the high-quality spectroscopic redshifts currently available to train, validate, and test them are substantially non-representative in both magnitude and colour. We investigate the nature and structure of this bias by tracking how objec…
High-resolution radiative transfer modelling of M33
De Looze, Ilse; Baes, Maarten; Smith, Matthew W. L. +4 more
In this work, we characterize the contributions from both ongoing star formation and the ambient radiation field in Local Group galaxy M33, as well as estimate the scale of the local dust-energy balance (i.e. the scale at which the dust is re-emitting starlight generated in that same region) in this galaxy through high-resolution radiative transfe…
Ongoing star formation at the outskirts of Sextans A: spectroscopic detection of early O-type stars
Garcia, Miriam; Herrero, Artemio; Najarro, Francisco +2 more
With both nebular- and stellar-derived abundances of ≲1/10 Z_{⊙ } and low foreground extinction, Sextans A is a prime candidate to replace the Small Magellanic Cloud as reservoir of metal-poor massive stars and reference to study the metal-poor Universe. We report the discovery of two early O-type stars in Sextans A, the earliest O-type stars with…
Revisiting the potassium feature of WASP-31b at high resolution
Nikolov, Nikolay; de Mooij, Ernst J. W.; Gibson, Neale P. +4 more
The analysis and interpretation of exoplanet spectra from time-series observations remains a significant challenge to our current understanding of exoplanet atmospheres, due to the complexities in understanding instrumental systematics. Previous observations of the hot Jupiter WASP-31b using transmission spectroscopy at low resolution have present…