Search Publications
A Panchromatic View of the Bulge Globular Cluster NGC 6569
Dalessandro, E.; Salaris, M.; Saracino, S. +12 more
We used high-resolution optical Hubble Space Telescope/WFC3 and multiconjugate adaptive optics assisted GEMINI GeMS/Gemini South Adaptive Optics Imager observations in the near-infrared (NIR) to investigate the physical properties of the globular cluster (GC) NGC 6569 in the Galactic bulge. We have obtained the deepest purely NIR color-magnitude d…
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…
Atomic Transition Probabilities for UV and Blue Lines of Fe II and Abundance Determinations in the Photospheres of the Sun and Metal-poor Star HD 84937
Sneden, C.; Lawler, J. E.; Den Hartog, E. A. +2 more
We report new branching fractions (BFs) for 121 UV lines from the low-lying odd-parity levels of Fe II belonging to the z6Do, z6Fo, z6Po, z4Fo, z4Do, and z4Po terms of the 3d6(5D)4p configuration…
Ruprecht 147: A Paradigm of Dissolving Star Cluster
Carraro, Giovanni; Seleznev, Anton F.; Montalto, Marco +1 more
We employed recent Gaia/DR2 data to investigate the dynamical status of the nearby (300 pc), old (2.5 Gyr) open cluster Ruprecht 147. We found prominent leading and trailing tails of stars along the cluster orbit, which demonstrates that Ruprecht 147 is losing stars at fast pace. Star counts indicate the cluster has a core radius of 33.3 arcmin an…
Tracing Kinematic and Chemical Properties of Sagittarius Stream by K-Giants, M-Giants, and BHB stars
Tian, Hao; Zhao, Gang; Wu, Yaqian +12 more
We characterize the kinematic and chemical properties of ∼3000 Sagittarius (Sgr) stream stars, including K-giants, M-giants, and blue horizontal branch stars (BHBs), selected from SEGUE-2, Large Sky Area Multi-Object Fibre Spectroscopic Telescope, and Sloan Digital Sky Survey separately in Integrals-of-Motion space. The orbit of the Sgr stream is …
SN 2016coi (ASASSN-16fp): An Energetic H-stripped Core-collapse Supernova from a Massive Stellar Progenitor with Large Mass Loss
Hurley, K.; Challis, P.; Stanek, K. Z. +26 more
We present comprehensive observations and analysis of the energetic H-stripped SN 2016coi (a.k.a. ASASSN-16fp), spanning the γ-ray through optical and radio wavelengths, acquired within the first hours to ∼420 days post explosion. Our observational campaign confirms the identification of He in the supernova (SN) ejecta, which we interpret to be ca…
Finding the Brightest Cosmic Beacons in the Southern Hemisphere
Grazian, Andrea; Boutsia, Konstantina; Amorin, Ricardo +6 more
The study of absorptions along the lines of sight to bright high-z QSOs is an invaluable cosmological tool that provides a wealth of information on the inter-/circum-galactic medium, dark matter, primordial elements, reionization, fundamental constants, and general relativity. Unfortunately, the number of bright (i ≲ 18) QSOs at z ≳ 2 in the south…
The mutual orbit, mass, and density of transneptunian binary Gǃkúnǁ'hòmdímà (229762 2007 UK126)
Buie, M. W.; Ragozzine, D.; Roe, H. G. +3 more
We present high spatial resolution images of the binary transneptunian object Gǃkúnǁ'hòmdímà (229762 2007 UK126) obtained with the Hubble Space Telescope and with the Keck observatory on Mauna Kea to determine the orbit of Gǃò'é ǃhúGǃò'é ǃhú, the much smaller and redder satellite. Gǃò'é ǃhú orbits in a prograde sense, on a circular or n…
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…
Spatially resolved spectroscopy of the debris disk HD 32297. Further evidence of small dust grains
Augereau, J. -C.; Pantin, E.; Henning, T. +14 more
Context. Spectro-photometry of debris disks in total intensity and polarimetry can provide new insight into the properties of the dust grains therein (size distribution and optical properties).
Aims: We aim to constrain the morphology of the highly inclined debris disk HD 32297. We also intend to obtain spectroscopic and polarimetric measurem…