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Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. II. Atomic Diffusion in M67 Stars
DOI: 10.3847/1538-4357/ab0b43 Bibcode: 2019ApJ...874...97S

Bovy, Jo; Pan, Kaike; Cunha, Katia +14 more

Chemical abundances for 15 elements (C, N, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, and Ni) are presented for 83 stellar members of the 4 Gyr old solar-metallicity open cluster M67. The sample contains stars spanning a wide range of evolutionary phases, from G dwarfs to red clump stars. The abundances were derived from near-IR (λ1.5-1.7 µ…

2019 The Astrophysical Journal
Gaia 74
Physical Characterization of an Unlensed, Dusty Star-forming Galaxy at z = 5.85
DOI: 10.3847/1538-4357/ab52ff Bibcode: 2019ApJ...887...55C

Finkelstein, Steven L.; Casey, Caitlin M.; Kartaltepe, Jeyhan S. +23 more

We present a physical characterization of MM J100026.36+021527.9 (a.k.a. “MAMBO-9”), a dusty star-forming galaxy (DSFG) at z = 5.850 ± 0.001. This is the highest-redshift unlensed DSFG (and fourth most distant overall) found to date and is the first source identified in a new 2 mm blank-field map in the COSMOS field. Though identified in prior sam…

2019 The Astrophysical Journal
eHST 74
Signatures of resonance and phase mixing in the Galactic disc
DOI: 10.1093/mnras/stz2667 Bibcode: 2019MNRAS.490.1026H

Bovy, Jo; Kawata, Daisuke; Mackereth, J. Ted +3 more

Gaia DR2 has provided an unprecedented wealth of information about the kinematics of stars in the Solar neighbourhood, and has highlighted the degree of features in the Galactic disc. We confront the data with a range of bar and spiral models in both action-angle space, and the RG-vϕ plane. We find that the phase mixing induc…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 74
XCLUMPY: X-Ray Spectral Model from Clumpy Torus and Its Application to the Circinus Galaxy
DOI: 10.3847/1538-4357/ab1b20 Bibcode: 2019ApJ...877...95T

Fukazawa, Yasushi; Tanimoto, Atsushi; Ueda, Yoshihiro +3 more

We construct an X-ray spectral model from the clumpy torus in an active galactic nucleus, designated as “XCLUMPY,” utilizing the Monte Carlo simulation for Astrophysics and Cosmology framework. The adopted geometry of the torus is the same as that in Nenkova et al. who assume a power-law distribution of clumps in the radial direction and a normal …

2019 The Astrophysical Journal
Suzaku XMM-Newton 74
Homogeneous Analysis of Hot Earths: Masses, Sizes, and Compositions
DOI: 10.3847/1538-4357/ab3a3b Bibcode: 2019ApJ...883...79D

Winn, Joshua N.; Dai, Fei; Masuda, Kento +1 more

Terrestrial planets have been found orbiting Sun-like stars with extremely short periods—some as short as 4 hr. These “ultra-short-period planets” or “hot Earths” are so strongly irradiated that any initial H/He atmosphere has probably been lost to photoevaporation. As such, the sample of hot Earths may give us a glimpse at the rocky cores that ar…

2019 The Astrophysical Journal
Gaia eHST 74
GRRMHD simulations of tidal disruption event accretion discs around supermassive black holes: jet formation, spectra, and detectability
DOI: 10.1093/mnras/sty3134 Bibcode: 2019MNRAS.483..565C

Narayan, Ramesh; Curd, Brandon

We report results from general relativistic radiation magnetohydrodynamics (GRRMHD) simulations of a super-Eddington black hole (BH) accretion disc formed as a result of a tidal disruption event (TDE). We consider the fiducial case of a solar mass star on a mildly penetrating orbit disrupted by a supermassive BH of mass 10^6 M_⊙, and consider the …

2019 Monthly Notices of the Royal Astronomical Society
XMM-Newton 74
Effects of anisotropic stress in interacting dark matter - dark energy scenarios
DOI: 10.1093/mnras/sty2789 Bibcode: 2019MNRAS.482.1858Y

Yang, Weiqiang; Xu, Lixin; Pan, Supriya +1 more

We study a novel interacting dark energy - dark matter scenario where the anisotropic stress of the large-scale inhomogeneities is considered. The dark energy has a constant equation of state and the interaction model produces stable perturbations. The resulting picture is constrained using different astronomical data aiming to measure the impact …

2019 Monthly Notices of the Royal Astronomical Society
eHST 74
Identification of Young Stellar Object candidates in the Gaia DR2 x AllWISE catalogue with machine learning methods
DOI: 10.1093/mnras/stz1301 Bibcode: 2019MNRAS.487.2522M

Szabados, L.; Beck, R.; Ábrahám, P. +8 more

The second Gaia Data Release (DR2) contains astrometric and photometric data for more than 1.6 billion objects with mean Gaia G magnitude <20.7, including many Young Stellar Objects (YSOs) in different evolutionary stages. In order to explore the YSO population of the Milky Way, we combined the Gaia DR2 data base with Wide-field Infrared Survey…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 74
Upper Bound of Neutrino Masses from Combined Cosmological Observations and Particle Physics Experiments
DOI: 10.1103/PhysRevLett.123.081301 Bibcode: 2019PhRvL.123h1301L

Lahav, Ofer; Manera, Marc; Loureiro, Arthur +9 more

We investigate the impact of prior models on the upper bound of the sum of neutrino masses, ∑mν . Using data from the large scale structure of galaxies, cosmic microwave background, type Ia supernovae, and big bang nucleosynthesis, we argue that cosmological neutrino mass and hierarchy determination should be pursued using exact models,…

2019 Physical Review Letters
eHST 74
Disentangling the Planet from the Star in Late-Type M Dwarfs: A Case Study of TRAPPIST-1g
DOI: 10.3847/1538-3881/aaf04d Bibcode: 2019AJ....157...11W

Bourrier, V.; Wakeford, H. R.; Lewis, N. K. +10 more

The atmospheres of late M stars represent a significant challenge in the characterization of any transiting exoplanets because of the presence of strong molecular features in the stellar atmosphere. TRAPPIST-1 is an ultracool dwarf, host to seven transiting planets, and contains its own molecular signatures that can potentially be imprinted on pla…

2019 The Astronomical Journal
Gaia eHST 73