Search Publications
The onset of star formation 250 million years after the Big Bang
Ouchi, Masami; Harikane, Yuichi; Inoue, Akio K. +21 more
A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang1-3. The abundance of star-forming galaxies is known to decline4,5 from redshifts of about 6 to 10, but a key question is the extent of star formation …
Disks around T Tauri Stars with SPHERE (DARTTS-S). I. SPHERE/IRDIS Polarimetric Imaging of Eight Prominent T Tauri Disks
Benisty, Myriam; Garufi, Antonio; Pinte, Christophe +7 more
We present the first part of our Disks ARound T Tauri Stars with SPHERE (DARTTS-S) survey: observations of eight T Tauri stars that were selected based on their strong (sub)millimeter excesses using SPHERE/IRDIS polarimetric differential imaging in the J and H bands. All observations successfully detect the disks, which appear vastly different in …
In Disguise or Out of Reach: First Clues about In Situ and Accreted Stars in the Stellar Halo of the Milky Way from Gaia DR2
Haywood, M.; Gómez, A.; Lehnert, M. D. +3 more
We investigate the nature of the double color-magnitude sequence observed in the Gaia DR2 HR diagram of stars with high transverse velocities. The stars in the reddest-color sequence are likely dominated by the dynamically hot tail of the thick disk population. Information from Nissen & Schuster and from the APOGEE survey suggests that stars i…
The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at z ∼ 3
Pettini, Max; Shapley, Alice E.; Steidel, Charles C. +5 more
We present results of a deep spectroscopic survey quantifying the statistics of the escape of ionizing radiation from star-forming galaxies at z ∼ 3. We measure the ratio of ionizing to non-ionizing UV flux density < {f}900{/f}1500{> }obs}, where f 900 is the mean flux density evaluated over the ra…
Helium in the eroding atmosphere of an exoplanet
Ehrenreich, D.; Udry, S.; Bourrier, V. +20 more
Helium is the second-most abundant element in the Universe after hydrogen and is one of the main constituents of gas-giant planets in our Solar System. Early theoretical models predicted helium to be among the most readily detectable species in the atmospheres of exoplanets, especially in extended and escaping atmospheres1. Searches for…
The White Dwarf Initial-Final Mass Relation for Progenitor Stars from 0.85 to 7.5 M ⊙
Choi, Jieun; Ramirez-Ruiz, Enrico; Tremblay, P. -E. +2 more
We present the initial-final mass relation (IFMR) based on the self-consistent analysis of Sirius B and 79 white dwarfs from 13 star clusters. We have also acquired additional signal on eight white dwarfs previously analyzed in the NGC 2099 cluster field, four of which are consistent with membership. These re-observed white dwarfs have masses rang…
Full-data Results of Hubble Frontier Fields: UV Luminosity Functions at z ∼ 6-10 and a Consistent Picture of Cosmic Reionization
Ono, Yoshiaki; Ouchi, Masami; Shimasaku, Kazuhiro +3 more
We present UV luminosity functions of dropout galaxies at z∼ 6{--}10 with the complete Hubble Frontier Fields data. We obtain a catalog of ∼450 dropout-galaxy candidates (350, 66, and 40 at z∼ 6{--}7, 8, and 9, respectively), with UV absolute magnitudes that reach ∼ -14 mag, ∼2 mag deeper than the Hubble Ultra Deep Field detection limits. We caref…
From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context
Fortney, Jonathan J.; Désert, Jean-Michel; Showman, Adam P. +10 more
Context. A new class of exoplanets has emerged: the ultra hot Jupiters, the hottest close-in gas giants. The majority of them have weaker-than-expected spectral features in the 1.1-1.7 µm bandpass probed by HST/WFC3 but stronger spectral features at longer wavelengths probed by Spitzer. This led previous authors to puzzling conclusions about…
Low-redshift Lyman continuum leaking galaxies with high [O III]/[O II] ratios
Schaerer, D.; Thuan, T. X.; Izotov, Y. I. +4 more
We present observations with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope of five star-forming galaxies at redshifts z in the range 0.2993-0.4317 and with high emission-line flux ratios O32 = [O III] λ5007/[O II] λ3727 ∼ 8-27 aiming to detect the Lyman continuum (LyC) emission. We detect LyC emission in all g…
ATLASGAL - properties of a complete sample of Galactic clumps
König, C.; Menten, K. M.; Smith, M. D. +15 more
The APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) is an unbiased 870 µm submillimetre survey of the inner Galactic plane (|ℓ| < 60° with |b| < 1.5°). It is the largest and most sensitive ground-based submillimetre wavelength Galactic survey to date and has provided a large and systematic inventory of all massive, dense clum…