Search Publications
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2016 follow-up campaign - I. Overview and classification of candidates selected by two techniques
Smith, M.; D'Andrea, C. B.; Abbott, T. M. C. +79 more
The primary goals of the STRong lensing Insights into the Dark Energy Survey (STRIDES) collaboration are to measure the dark energy equation of state parameter and the free streaming length of dark matter. To this aim, STRIDES is discovering strongly lensed quasars in the imaging data of the Dark Energy Survey and following them up to measure time…
An application of an optimal statistic for characterizing relative orientations
Martin, P. G.; Poidevin, F.; Hill, Ryley +5 more
We present the projected Rayleigh statistic (PRS), a modification of the classic Rayleigh statistic, as a test for non-uniform relative orientation between two pseudo-vector fields. In the application here, this gives an effective way of investigating whether polarization pseudo-vectors (spin-2 quantities) are preferentially parallel or perpendicu…
A catalog of polychromatic bulge-disc decompositions of ∼17.600 galaxies in CANDELS
Barro, Guillermo; Pérez-González, Pablo G.; Kocevski, Dale D. +20 more
Understanding how bulges grow in galaxies is a critical step towards unveiling the link between galaxy morphology and star-formation. To do so, it is necessary to decompose large sample of galaxies at different epochs into their main components (bulges and discs). This is particularly challenging, especially at high redshifts, where galaxies are p…
Spatially unresolved SED fitting can underestimate galaxy masses: a solution to the missing mass problem
Sawicki, Marcin; Sorba, Robert
We perform spatially resolved, pixel-by-pixel Spectral Energy Distribution (SED) fitting on galaxies up to z ∼ 2.5 in the Hubble eXtreme Deep Field (XDF). Comparing stellar mass estimates from spatially resolved and spatially unresolved photometry we find that unresolved masses can be systematically underestimated by factors of up to 5. The ratio …
Constraining the multiplicity statistics of the coolest brown dwarfs: binary fraction continues to decrease with spectral type
Allers, Katelyn; Bonavita, Mariangela; Fontanive, Clémence +1 more
Binary statistics of the latest-type T and Y brown dwarfs are sparse and it is unclear whether the trends seen in the multiplicity properties of their more massive counterparts hold for the very coolest brown dwarfs. We present results from a search for substellar and planetary-mass companions to a sample of 12 ultracool T8-Y0 field brown dwarfs w…
Searching for outflows in ultraluminous X-ray sources through high-resolution X-ray spectroscopy
Fabian, A. C.; Pinto, C.; Walton, D. J. +1 more
Ultraluminous X-ray sources (ULXs) are non-nuclear point sources exceeding the Eddington luminosity of a 10 M⊙ black hole. Modern consensus for a majority of the ULX population is that they are powered by stellar-mass black holes or neutron stars accreting well above the Eddington limit. Theoretical models of super-Eddington accretion p…
The unusual late-time evolution of the tidal disruption event ASASSN-15oi
Kochanek, C. S.; Shappee, B. J.; Brown, J. S. +4 more
We present late-time optical spectroscopy and X-ray, UV, and optical photometry of the nearby (d = 214 Mpc, z = 0.0479) tidal disruption event (TDE) ASASSN-15oi. The optical spectra span 450 days after discovery and show little remaining transient emission or evolution after roughly three months. In contrast, the Swift and XMM-Newton observations …
MAHALO Deep Cluster Survey II. Characterizing massive forming galaxies in the Spiderweb protocluster at z = 2.2
Cai, Zheng; Suzuki, Tomoko L.; Koyama, Yusei +10 more
This paper is the second in a series presenting the results of our deep H α-line survey towards protoclusters at z > 2, based on narrow-band imaging with the Subaru Telescope. This work investigates massive galaxies in a protocluster region associated with a radio galaxy (PKS 1138 - 262), the Spiderweb galaxy, at z = 2.2. Our 0.5 mag deeper nar…
The young star cluster population of M51 with LEGUS - II. Testing environmental dependences
Östlin, G.; Dale, D. A.; Calzetti, D. +16 more
It has recently been established that the properties of young star clusters (YSCs) can vary as a function of the galactic environment in which they are found. We use the cluster catalogue produced by the Legacy Extragalactic UV Survey (LEGUS) collaboration to investigate cluster properties in the spiral galaxy M51. We analyse the cluster populatio…
Star formation history of the Galactic bulge from deep HST imaging of low reddening windows
Hill, Vanessa; Di Matteo, Paola; Haywood, Misha +3 more
Despite the huge amount of photometric and spectroscopic efforts targeting the Galactic bulge over the past few years, its age distribution remains controversial owing to both the complexity of determining the age of individual stars and the difficult observing conditions. Taking advantage of the recent release of very deep, proper-motion-cleaned …