Search Publications
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6
Ono, Yoshiaki; Ouchi, Masami; Goto, Tomotsugu +44 more
We present new measurements of the quasar luminosity function (LF) at z ∼ 6 over an unprecedentedly wide range of the rest-frame ultraviolet luminosity M 1450 from -30 to -22 mag. This is the fifth in a series of publications from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multiban…
Why do protoplanetary disks appear not massive enough to form the known exoplanet population?
Manara, C. F.; Morbidelli, A.; Guillot, T.
When and how planets form in protoplanetary disks is still a topic of discussion. Exoplanet detection surveys and protoplanetary disk surveys are now providing results that are leading to new insights. We collect the masses of confirmed exoplanets and compare their dependence on stellar mass with the same dependence for protoplanetary disk masses …
The Sausage Globular Clusters
Myeong, G. C.; Evans, N. W.; Belokurov, V. +2 more
The Gaia Sausage is an elongated structure in velocity space discovered by Belokurov et al. using the kinematics of metal-rich halo stars. They showed that it could be created by a massive dwarf galaxy (∼5 × 1010 {M}⊙ ) on a strongly radial orbit that merged with the Milky Way at a redshift z ≲ 3. This merger would also have …
The evolution of the X-ray afterglow emission of GW 170817/ GRB 170817A in XMM-Newton observations
Covino, S.; D'Avanzo, P.; Campana, S. +12 more
We report our observation of the short gamma-ray burst (GRB) GRB 170817A, associated to the binary neutron star merger gravitational wave (GW) event GW 170817, performed in the X-ray band with XMM-Newton 135 d after the event (on 29 December, 2017). We find evidence for a flattening of the X-ray light curve with respect to the previously observed …
The Hipparcos-Gaia Catalog of Accelerations
Brandt, Timothy D.
This paper presents a cross-calibrated catalog of Hipparcos and Gaia astrometry to enable their use in measuring changes in proper motion, i.e., accelerations in the plane of the sky. The final catalog adopts the reference frame of the second Gaia data release (DR2) and locally cross-calibrates both the scaled Hipparcos-Gaia DR2 positional differe…
Dark Energy Survey Year 1 results: weak lensing shape catalogues
Benoit-Lévy, A.; Bechtol, K.; Smith, M. +105 more
We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 deg2 with a median redshift of 0.59. The catalogues cover two main fields: Stripe 82, and an area overlapping the South Pole Telescope survey region. We describe our data analysis process and in particular our shape measurement using two in…
A Decline in the X-Ray through Radio Emission from GW170817 Continues to Support an Off-axis Structured Jet
Berger, E.; Chornock, R.; Fong, W. +17 more
We present new observations of the binary neutron star merger GW170817 at Δt ≈ 220-290 days post-merger, at radio (Karl G. Jansky Very Large Array; VLA), X-ray (Chandra X-ray Observatory), and optical (Hubble Space Telescope; HST) wavelengths. These observations provide the first evidence for a turnover in the X-ray light curve, mirroring a declin…
Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet
Ehrenreich, D.; Lecavelier des Etangs, A.; Lovis, C. +7 more
Stellar heating causes atmospheres of close-in exoplanets to expand and escape. These extended atmospheres are difficult to observe because their main spectral signature—neutral hydrogen at ultraviolet wavelengths—is strongly absorbed by interstellar medium. We report the detection of the near-infrared triplet of neutral helium in the transiting w…
Three-dimensional maps of interstellar dust in the Local Arm: using Gaia, 2MASS, and APOGEE-DR14
Arenou, F.; Babusiaux, C.; Leclerc, N. +6 more
Context. Gaia data and stellar surveys open the way to the construction of detailed 3D maps of the Galactic interstellar (IS) dust based on the synthesis of star distances and extinctions. Dust maps are tools of broad use, also for Gaia-related Milky Way studies.
Aims: Reliable extinction measurements require very accurate photometric calibra…
Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop
Done, Chris; Noda, Hirofumi
We model the broad-band (optical/UV and X-ray) continuum spectrum of the `changing-look' active galactic nucleus (AGN) Mrk 1018, as it fades from Seyfert 1 to 1.9 in ∼ 8 years. The brightest spectrum, with Eddington ratio L/LEdd ∼ 0.08 has a typical type 1 AGN continuum, with a strong `soft X-ray excess' spanning between the UV and soft…