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Gaia kinematics reveal a complex lopsided and twisted Galactic disc warp
DOI: 10.1051/0004-6361/201834908 Bibcode: 2019A&A...627A.150R

Castro-Ginard, A.; Figueras, F.; Romero-Gómez, M. +2 more

Context. There are few warp kinematic models of the Galaxy able to characterise both structure and kinematics, since these require high accuracy at large distances. These models are necessary to shed light on the lopsidedness of the warp and the twisting of the line-of-nodes of the stellar warp already seen in gas and dust.
Aims: We use the v…

2019 Astronomy and Astrophysics
Gaia 58
Global 3D Hydrodynamic Modeling of In-transit Lyα Absorption of GJ 436b
DOI: 10.3847/1538-4357/ab46a4 Bibcode: 2019ApJ...885...67K

Lammer, H.; Khodachenko, M. L.; Shaikhislamov, I. F. +5 more

Using a global 3D, fully self-consistent, multifluid hydrodynamic model, we simulate the escaping upper atmosphere of the warm Neptune GJ 436b, driven by the stellar X-ray and ultraviolet (XUV) radiation impact and gravitational forces and interacting with the stellar wind. Under the typical parameters of XUV flux and stellar wind plasma expected …

2019 The Astrophysical Journal
eHST 58
Morphologies of ∼190,000 Galaxies at z = 0-10 Revealed with HST Legacy Data. III. Continuum Profile and Size Evolution of Lyα Emitters
DOI: 10.3847/1538-4357/aaf64b Bibcode: 2019ApJ...871..164S

Ouchi, Masami; Harikane, Yuichi; Shibuya, Takatoshi +1 more

We present the redshift evolution of the radial surface brightness profile of the rest-frame UV and optical stellar continua for 9119 Lyα emitters (LAEs) at z ≃ 0-8 and 0-2, respectively. Using Hubble Space Telescope data and the LAE catalogs taken from the literature, we derive the structural quantities of the 9119 LAEs, and of ≃180,000 of photo-…

2019 The Astrophysical Journal
eHST 58
Nuclear molecular outflow in the Seyfert galaxy NGC 3227
DOI: 10.1051/0004-6361/201935431 Bibcode: 2019A&A...628A..65A

Rigopoulou, D.; Hunt, L. K.; Vestergaard, M. +24 more

ALMA observations have revealed nuclear dusty molecular disks or tori with characteristic sizes 15-40 pc in the few Seyferts and low -luminosity AGN that have been studied so far. These structures are generally decoupled both morphologically and kinematically from the host galaxy disk. We present ALMA observations of the CO(2-1) and CO(3-2) molecu…

2019 Astronomy and Astrophysics
eHST 58
Boötes. IV. A new Milky Way satellite discovered in the Subaru Hyper Suprime-Cam Survey and implications for the missing satellite problem
DOI: 10.1093/pasj/psz076 Bibcode: 2019PASJ...71...94H

Strauss, Michael A.; Wang, Shiang-Yu; Ishigaki, Miho N. +13 more

We report on the discovery of a new Milky Way (MW) satellite in Boötes based on data from the ongoing Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP). This satellite, named Boötes IV, is the third ultra-faint dwarf that we have discovered in the HSC-SSP. We have identified a statistically significant (32.3σ) overdensity of stars with charac…

2019 Publications of the Astronomical Society of Japan
eHST 58
A ring in a shell: the large-scale 6D structure of the Vela OB2 complex
DOI: 10.1051/0004-6361/201834003 Bibcode: 2019A&A...621A.115C

Jordi, C.; Cantat-Gaudin, T.; Balaguer-Núñez, L. +3 more

Context. The Vela OB2 association is a group of ∼10 Myr stars exhibiting a complex spatial and kinematic substructure. The all-sky Gaia DR2 catalogue contains proper motions, parallaxes (a proxy for distance), and photometry that allow us to separate the various components of Vela OB2.
Aims: We characterise the distribution of the Vela OB2 st…

2019 Astronomy and Astrophysics
Gaia 58
Confirming Herschel Candidate Protoclusters from ALMA/VLA CO Observations
DOI: 10.3847/1538-4357/ab002a Bibcode: 2019ApJ...872..117G

Pérez-Fournon, I.; Valtchanov, I.; Clements, D. L. +11 more

ALMA 870 µm continuum imaging has uncovered a population of blends of multiple dusty star-forming galaxies (DSFGs) in sources originally detected with the Herschel Space Observatory. However, their pairwise separations are much smaller than what is found by ALMA follow-up of other single-dish surveys or expected from theoretical simulations.…

2019 The Astrophysical Journal
Herschel 58
Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions Using Gaia
DOI: 10.3847/1538-4357/ab441f Bibcode: 2019ApJ...886...68A

Breivik, Katelyn; Andrews, Jeff J.; Chatterjee, Sourav

In astrometric binaries, the presence of a dark, unseen star can be inferred from the gravitational pull it induces on its luminous binary companion. While the orbit of such binaries can be characterized with precise astrometric measurements, constraints made from astrometry alone are not enough to measure the component masses. In this work, we de…

2019 The Astrophysical Journal
Gaia 58
Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event
DOI: 10.3847/1538-4357/ab24de Bibcode: 2019ApJ...879..119H

Cenko, S. B.; Veilleux, S.; Foley, Ryan J. +25 more

We report the discovery of nonstellar hydrogen Balmer and metastable helium absorption lines accompanying a transient, high-velocity (0.05c) broad absorption line (BAL) system in the optical spectra of the tidal disruption event (TDE) AT2018zr (z = 0.071). In the Hubble Space Telescope UV spectra, absorption of high- and low-ionization lines is al…

2019 The Astrophysical Journal
eHST 58
The Gaia-ESO survey: Calibrating a relationship between age and the [C/N] abundance ratio with open clusters
DOI: 10.1051/0004-6361/201935282 Bibcode: 2019A&A...629A..62C

Gilmore, G.; Bayo, A.; Prada Moroni, P. G. +51 more

Context. In the era of large high-resolution spectroscopic surveys such as Gaia-ESO and APOGEE, high-quality spectra can contribute to our understanding of the Galactic chemical evolution by providing abundances of elements that belong to the different nucleosynthesis channels, and also by providing constraints to one of the most elusive astrophys…

2019 Astronomy and Astrophysics
Gaia 58