Search Publications
Physical properties of AM CVn stars: New insights from Gaia DR2
Knigge, C.; Groot, P. J.; Breedt, E. +9 more
AM CVn binaries are hydrogen deficient compact binaries with an orbital period in the 5-65 min range and are predicted to be strong sources of persistent gravitational wave radiation. Using Gaia Data Release 2, we present the parallaxes and proper motions of 41 out of the 56 known systems. Compared to the parallax determined using the HST Fine Gui…
A deep X-ray view of the bare AGN Ark 120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes
Harrison, F.; Stern, D.; Zhang, W. W. +16 more
Context. The physical characteristics of the material closest to supermassive black holes (SMBHs) are primarily studied through X-ray observations. However, the origins of the main X-ray components such as the soft X-ray excess, the Fe Kα line complex, and the hard X-ray excess are still hotly debated. This is particularly problematic for active g…
Physical properties and H-ionizing-photon production rates of extreme nearby star-forming regions
Feltre, Anna; Charlot, Stéphane; Chevallard, Jacopo +7 more
Measurements of the galaxy UV luminosity function at z ≳ 6 suggest that young stars hosted in low-mass star-forming galaxies produced the bulk of hydrogen-ionizing photons necessary to reionize the intergalactic medium (IGM) by redshift z ∼ 6. Whether star-forming galaxies dominated cosmic reionization, however, also depends on their stellar popul…
Observations and Impacts of the 10 September 2017 Solar Events at Mars: An Overview and Synthesis of the Initial Results
Holmström, M.; Luhmann, J. G.; Halekas, J. S. +8 more
On 10 September 2017, some of the strongest solar activity occurred in association with active region 12673 (AR2673), including an X-class solar flare and a fast coronal mass ejection. Although AR2673 was not centrally facing Mars, the activity impacted the local space weather conditions at Mars. We give an overview of observations obtained from t…
Water, High-altitude Condensates, and Possible Methane Depletion in the Atmosphere of the Warm Super-Neptune WASP-107b
Stevenson, Kevin B.; Kreidberg, Laura; Line, Michael R. +2 more
The super-Neptune exoplanet WASP-107b is an exciting target for atmosphere characterization. It has an unusually large atmospheric scale height and a small, bright host star, raising the possibility of precise constraints on its current nature and formation history. We report the first atmospheric study of WASP-107b, a Hubble Space Telescope (HST)…
The Bright-end Galaxy Candidates at z ∼ 9 from 79 Independent HST Fields
Shull, J. M.; Treu, T.; Mason, C. A. +11 more
We present a full data analysis of the pure-parallel Hubble Space Telescope (HST) imaging observations in the Brightest of Reionizing Galaxies Survey (BoRG[z9]) in Cycle 22. The medium-deep exposures with five HST/WFC3IR+UVIS filter bands from 79 independent sightlines (∼370 arcmin2) provide the least biased determination of number dens…
Connecting young star clusters to CO molecular gas in NGC 7793 with ALMA-LEGUS
Gallagher, J. S.; Dale, D. A.; Calzetti, D. +20 more
We present an investigation of the relationship between giant molecular cloud (GMC) properties and the associated stellar clusters in the nearby flocculent galaxy NGC 7793. We combine the star cluster catalogue from the HST LEGUS (Legacy ExtraGalactic UV Survey) programme with the 15 pc resolution ALMA CO(2-1) observations. We find a strong spatia…
Precise Time Delays from Strongly Gravitationally Lensed Type Ia Supernovae with Chromatically Microlensed Images
Nugent, Peter E.; Collett, Thomas E.; Goldstein, Daniel A. +1 more
Time delays between the multiple images of strongly gravitationally lensed Type Ia supernovae (glSNe Ia) have the potential to deliver precise cosmological constraints, but the effects of microlensing on time delay extraction have not been studied in detail. Here we quantify the effect of microlensing on the glSN Ia yield of the Large Synoptic Sur…
The Complex Morphology of the Young Disk MWC 758: Spirals and Dust Clumps around a Large Cavity
Tang, Ya-Wen; Ricci, L.; Benisty, M. +7 more
We present Atacama Large Millimeter Array observations at an angular resolution of 0.″1-0.″2 of the disk surrounding the young Herbig Ae star MWC 758. The data consist of images of the dust continuum emission recorded at 0.88 millimeter, as well as images of the 13CO and C18O J = 3-2 emission lines. The dust continuum emissio…
The VLT-FLAMES Tarantula Survey. XXIX. Massive star formation in the local 30 Doradus starburst
van Loon, J. Th.; Crowther, P. A.; Lennon, D. J. +24 more
The 30 Doradus (30 Dor) nebula in the Large Magellanic Cloud (LMC) is the brightest HII region in the Local Group and a prototype starburst similar to those found in high redshift galaxies. It is thus a stepping stone to understand the complex formation processes of stars in starburst regions across the Universe. Here, we have studied the formatio…