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Steep faint-end slopes of galaxy mass and luminosity functions at z≥ 6 and the implications for reionization
Jaacks, Jason; Choi, Jun-Hwan; Nagamine, Kentaro +2 more
We present the results of a numerical study comparing photometric and physical properties of simulated z= 6-9 galaxies to the observations taken by the Wide Field Camera 3 instrument aboard the Hubble Space Telescope. Using cosmological hydrodynamical simulations we find good agreement with observations in colour-colour space at all studied redshi…
A Monte Carlo Markov Chain Based Investigation of Black Hole Spin in the Active Galaxy NGC 3783
Fabian, Andrew C.; Brenneman, Laura W.; Reynolds, Christopher S. +4 more
The analysis of relativistically broadened X-ray spectral features from the inner accretion disk provides a powerful tool for measuring the spin of supermassive black holes in active galactic nuclei (AGNs). However, AGN spectra are often complex and careful analysis employing appropriate and self-consistent models is required if one has to obtain …
Overdensities of Y-dropout Galaxies from the Brightest-of-Reionizing Galaxies Survey: A Candidate Protocluster at Redshift z ≈ 8
Shull, J. M.; Treu, T.; Carollo, C. M. +8 more
Theoretical and numerical modeling of the assembly of dark-matter halos predicts that the most massive and luminous galaxies at high redshift are surrounded by overdensities of fainter companions. We test this prediction with Hubble Space Telescope observations acquired by our Brightest-of-Reionizing Galaxies (BoRG) survey, which identified four v…
The History and Environment of a Faded Quasar: Hubble Space Telescope Observations of Hanny's Voorwerp and IC 2497
Schawinski, Kevin; Keel, William C.; Thomas, Daniel +6 more
We present Hubble Space Telescope imaging and spectroscopy, along with supporting Galaxy Evolution Explorer and ground-based data, for the extended high-ionization cloud known as Hanny's Voorwerp, near the spiral galaxy IC 2497. Wide Field Camera 3 images show complex dust absorption near the nucleus of IC 2497. The galaxy core in these data is, w…
A Double Cluster at the Core of 30 Doradus
Panagia, N.; Anderson, J.; Lennon, D. J. +7 more
Based on an analysis of data obtained with the Wide Field Camera 3 on the Hubble Space Telescope we report the identification of two distinct stellar populations in the core of the giant H II region 30 Doradus in the Large Magellanic Cloud. The most compact and richest component coincides with the center of R136 and is ~1 Myr younger than a second…
No evidence for Lyman α emission in spectroscopy of z > 7 candidate galaxies
Wilkins, Stephen M.; Bunker, Andrew J.; Caruana, Joseph +5 more
We present Gemini/Gemini Near Infrared Spectrograph (GNIRS) spectroscopic observations of four z-band (z ≈ 7) dropout galaxies and Very Large Telescope (VLT)/XSHOOTER observations of one z-band dropout and three Y-band (z ≈ 8-9) dropout galaxies in the Hubble Ultra Deep Field, which were selected with Wide Field Camera 3 imaging on the Hubble Spac…
Detection of Elements at All Three r-process Peaks in the Metal-poor Star HD 160617
Roederer, Ian U.; Lawler, James E.
We report the first detection of elements at all three r-process peaks in the metal-poor halo star HD 160617. These elements include arsenic and selenium, which have not been detected previously in halo stars, and the elements tellurium, osmium, iridium, and platinum, which have been detected previously. Absorption lines of these elements are foun…
On the nature of the galactic early-B hypergiants
Howarth, I. D.; Urbaneja, M. A.; Negueruela, I. +3 more
Aims: Despite their importance to a number of astrophysical fields, the lifecycles of very massive stars are still poorly defined. In order to address this shortcoming, we present a detailed quantitative study of the physical properties of four early-B hypergiants (BHGs) of spectral type B1-4 Ia+; Cyg OB2 #12, ζ1 Sco, HD…
Far-infrared colours of nearby late-type galaxies in the Herschel Reference Survey
Clements, D. L.; Ciesla, L.; Buat, V. +21 more
We study the far infrared (60-500 µm) colours of late-type galaxies in the Herschel Reference Survey, a K-band selected, volume limited sample of nearby galaxies. The far infrared colours are correlated with each other, with tighter correlations for the indices that are closer in wavelength. We also compare the different colour indices to va…
Structure and Dynamics of the Magnetopause and Its Boundary Layers
Hasegawa, Hiroshi
The magnetopause is the key region in space for the transfer of solar wind mass, momentum, and energy into the magnetosphere. During the last decade, our understanding of the structure and dynamics of Earth's magnetopause and its boundary layers has advanced considerably, thanks largely to the advent of multi-spacecraft missions such as Cluster an…