Search Publications

Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids
DOI: 10.1126/science.aaw7462 Bibcode: 2020Sci...367.7462P

Longobardo, Andrea; Palomba, Ernesto; Schmitt, Bernard +29 more

The measured nitrogen-to-carbon ratio in comets is lower than for the Sun, a discrepancy which could be alleviated if there is an unknown reservoir of nitrogen in comets. The nucleus of comet 67P/Churyumov-Gerasimenko exhibits an unidentified broad spectral reflectance feature around 3.2 micrometers, which is ubiquitous across its surface. On the …

2020 Science
Rosetta 124
Dynamical Relics of the Ancient Galactic Halo
DOI: 10.3847/1538-4357/ab6ef7 Bibcode: 2020ApJ...891...39Y

Zhao, Gang; Myeong, G. C.; Evans, N. W. +11 more

We search for dynamical substructures in the LAMOST DR3 very metal-poor (VMP) star catalog. After cross-matching with Gaia DR2, there are ∼3300 VMP stars with available high-quality astrometric information that have halo-like kinematics. We apply a method based on the self-organizing map StarGO to find groups clustered in the 4D space of orbital e…

2020 The Astrophysical Journal
Gaia 124
Gravity-mode period spacings and near-core rotation rates of 611 γ Doradus stars with Kepler
DOI: 10.1093/mnras/stz2906 Bibcode: 2020MNRAS.491.3586L

Li, Gang; Bedding, Timothy R.; Antoci, Victoria +4 more

We report our survey of γ Dor stars from the 4-yr Kepler mission. These stars pulsate mainly in g modes and r modes, showing period-spacing patterns in the amplitude spectra. The period-spacing patterns are sensitive to the chemical composition gradients and the near-core rotation, hence they are essential for understanding the stellar interior. W…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 124
The mass of our Milky Way
DOI: 10.1007/s11433-019-1541-6 Bibcode: 2020SCPMA..6309801W

Ishigaki, Miho N.; Cautun, Marius; Wang, WenTing +2 more

We perform an extensive review of the numerous studies and methods used to determine the total mass of the Milky Way. We group the various studies into seven broad classes according to their modeling approaches. The classes include: i) estimating Galactic escape velocity using high velocity objects; ii) measuring the rotation curve through termina…

2020 Science China Physics, Mechanics, and Astronomy
Gaia 123
Constraining the masses of microlensing black holes and the mass gap with Gaia DR2
DOI: 10.1051/0004-6361/201935842 Bibcode: 2020A&A...636A..20W

Wyrzykowski, Łukasz; Mandel, Ilya

Context. Gravitational microlensing is sensitive to compact-object lenses in the Milky Way, including white dwarfs, neutron stars, or black holes, and could potentially probe a wide range of stellar-remnant masses. However, the mass of the lens can be determined only in very limited cases, due to missing information on both source and lens distanc…

2020 Astronomy and Astrophysics
Gaia 122
Cluster-galaxy weak lensing
DOI: 10.1007/s00159-020-00129-w Bibcode: 2020A&ARv..28....7U

Umetsu, Keiichi

Weak gravitational lensing of background galaxies provides a direct probe of the projected matter distribution in and around galaxy clusters. Here, we present a self-contained pedagogical review of cluster-galaxy weak lensing, covering a range of topics relevant to its cosmological and astrophysical applications. We begin by reviewing the theoreti…

2020 Astronomy and Astrophysics Review
eHST 120
The "hidden" companion in LB-1 unveiled by spectral disentangling
DOI: 10.1051/0004-6361/202038275 Bibcode: 2020A&A...639L...6S

Shenar, T.; Sana, H.; Hawcroft, C. +9 more

Context. The intriguing binary LS V +22 25 (LB-1) has drawn much attention following claims of it being a single-lined spectroscopic binary with a 79-day orbit comprising a B-type star and a ≈70 M black hole - the most massive stellar black hole reported to date. Subsequent studies demonstrated a lack of evidence for…

2020 Astronomy and Astrophysics
Gaia 120
Science with the TianQin Observatory: Preliminary results on Galactic double white dwarf binaries
DOI: 10.1103/PhysRevD.102.063021 Bibcode: 2020PhRvD.102f3021H

Huang, Shun-Jia; Hu, Yi-Ming; Korol, Valeriya +6 more

We explore the prospects of detecting Galactic double white dwarf (DWD) binaries with the space-based gravitational wave (GW) observatory TianQin. In this work, we analyze both a sample of currently known DWDs and a realistic synthetic population of DWDs to assess the number of guaranteed detections and the full capacity of the mission. We find th…

2020 Physical Review D
Gaia 120
The Open Cluster Chemical Abundances and Mapping Survey. IV. Abundances for 128 Open Clusters Using SDSS/APOGEE DR16
DOI: 10.3847/1538-3881/ab77bc Bibcode: 2020AJ....159..199D

Bizyaev, Dmitry; Brownstein, Joel R.; Pan, Kaike +22 more

The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to constrain key Galactic dynamical and chemical evolution parameters by the construction of a large, comprehensive, uniform, infrared-based spectroscopic data set of hundreds of open clusters. This fourth contribution from the OCCAM survey presents analysis using Sloan Digital S…

2020 The Astronomical Journal
Gaia 120
(Sub)stellar companions shape the winds of evolved stars
DOI: 10.1126/science.abb1229 Bibcode: 2020Sci...369.1497D

Waters, L. B. F. M.; Sahai, R.; De Ridder, J. +32 more

Binary interactions dominate the evolution of massive stars, but their role is less clear for low- and intermediate-mass stars. The evolution of a spherical wind from an asymptotic giant branch (AGB) star into a nonspherical planetary nebula (PN) could be due to binary interactions. We observed a sample of AGB stars with the Atacama Large Millimet…

2020 Science
Gaia 119