Search Publications
Effective Radii of Young, Massive Star Clusters in Two LEGUS Galaxies
Cignoni, M.; Gallagher, J. S.; Dale, D. A. +15 more
We present a study of the effective (half-light) radii and other structural properties of a systematically selected sample of young, massive star clusters (≥5 × 103 {M}⊙ and ≤200 Myr) in two nearby spiral galaxies, NGC 628 and NGC 1313. We use Hubble Space Telescope (HST) WFC3/UVIS and archival ACS/WFC data obtained by the L…
Drifting oscillations in axion monodromy
Westphal, Alexander; Flauger, Raphael; McAllister, Liam +1 more
We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-…
Rise of the Titans: A Dusty, Hyper-luminous “870 µm Riser” Galaxy at z ∼ 6
Marques-Chaves, Rui; Oliver, Seb; Cooray, Asantha +12 more
We report the detection of ADFS-27, a dusty, starbursting major merger at a redshift of z = 5.655, using the Atacama Large Millimeter/submillimeter Array (ALMA). ADFS-27 was selected from Herschel/Spectral and Photometric Imaging Receiver (SPIRE) and APEX/LABOCA data as an extremely red “870 µm riser” (I.e., {S}250µ {{m}}<…
VLT/FORS2 view at z 6: Lyman-α emitter fraction and galaxy physical properties at the edge of the epoch of cosmic reionization
Maiolino, R.; Dickinson, M.; Finkelstein, S. L. +10 more
The fraction of Lyman-α emitters (LAEs) among the galaxy population has been found to increase from z 0 to z 6 and drop dramatically at z> 6. This drop has been interpreted as an effect of an increasingly neutral intergalactic medium (IGM) with increasing redshift, while a Lyman continuum escape fraction evolving with redshift and/or a sudden c…
Temporal Evolution of the High-energy Irradiation and Water Content of TRAPPIST-1 Exoplanets
Delrez, L.; Demory, B. -O.; Ehrenreich, D. +13 more
The ultracool dwarf star TRAPPIST-1 hosts seven Earth-size transiting planets, some of which could harbor liquid water on their surfaces. Ultraviolet observations are essential to measuring their high-energy irradiation and searching for photodissociated water escaping from their putative atmospheres. Our new observations of the TRAPPIST-1 Lyα lin…
Properties of the molecular gas in the fast outflow in the Seyfert galaxy IC 5063
Morganti, Raffaella; Oosterloo, Tom; Combes, Françoise +5 more
We present a detailed study of the properties of the molecular gas in the fast outflow driven by the active galactic nucleus (AGN) in the nearby radio-loud Seyfert galaxy IC 5063. By using ALMA observations of a number of tracers of the molecular gas (12CO(1-0), 12CO(2-1), 12CO(3-2), 13CO(2-1) and HCO
The AMBRE project: The thick thin disk and thin thick disk of the Milky Way
Recio-Blanco, A.; de Laverny, P.; Hayden, M. R. +2 more
We analyze 494 main sequence turnoff and subgiant stars from the AMBRE:HARPS survey. These stars have accurate astrometric information from Gaia DR1, providing reliable age estimates with relative uncertainties of ±1 or 2 Gyr and allowing precise orbital determinations. The sample is split based on chemistry into a low-[Mg/Fe] sequence, which are …
Rotation of Late-type Stars in Praesepe with K2
Bouvier, J.; Hebb, L.; Rebull, L. M. +5 more
We have Fourier-analyzed 941 K2 light curves (LCs) of likely members of Praesepe, measuring periods for 86% and increasing the number of rotation periods (P) by nearly a factor of four. The distribution of P versus (V-{K}{{s}}), a mass proxy, has three different regimes: (V-{K}{{s}}) < 1.3, where the rotation rate rapidly …
Galactocentric variation of the gas-to-dust ratio and its relation with metallicity
König, C.; Menten, K. M.; Leurini, S. +6 more
Context. The assumption of a gas-to-dust mass ratio γ is a common approach to estimate the basic properties of molecular clouds, such as total mass and column density of molecular hydrogen, from (sub)mm continuum observations of the dust. In the Milky Way a single value is used at all galactocentric radii, independently of the observed metallicity…
An elevation of 0.1 light-seconds for the optical jet base in an accreting Galactic black hole system
Harrison, F. A.; Stern, D.; Altamirano, D. +25 more
Relativistic plasma jets are observed in many systems that host accreting black holes. According to theory, coiled magnetic fields close to the black hole accelerate and collimate the plasma, leading to a jet being launched1-3. Isolating emission from this acceleration and collimation zone is key to measuring its size and understanding …