Search Publications
Different Fates of Young Star Clusters after Gas Expulsion
Tang, Shih-Yun; Pang, Xiaoying; Pasquato, Mario +2 more
We identify structures of the young star cluster NGC 2232 in the solar neighborhood (323.0 pc) and a newly discovered star cluster, LP 2439 (289.1 pc). Member candidates are identified using the Gaia DR2 sky position, parallax, and proper-motion data by an unsupervised machine-learning method, STARGO. Member contamination from the Galactic disk is…
A statistical analysis of dust polarization properties in ALMA observations of Class 0 protostellar cores
Louvet, F.; Hennebelle, P.; Guillet, V. +8 more
Context. Recent observational progress has challenged the dust grain-alignment theories used to explain the polarized dust emission routinely observed in star-forming cores.
Aims: In an effort to improve our understanding of the dust grain alignment mechanism(s), we have gathered a dozen ALMA maps of (sub)millimeter-wavelength polarized dust …
High-resolution UV/Optical/IR Imaging of Jupiter in 2016-2019
de Pater, Imke; Wong, Michael H.; Fletcher, Leigh N. +13 more
Imaging observations of Jupiter with high spatial resolution were acquired beginning in 2016, with a cadence of 53 days to coincide with atmospheric observations of the Juno spacecraft during each perijove pass. The Wide Field Camera 3 (WFC3) aboard the Hubble Space Telescope (HST) collected Jupiter images from 236 to 925 nm in 14 filters. The Nea…
The Ionizing Photon Production Efficiency (ξion) of Lensed Dwarf Galaxies at z ∼ 2
Richard, Johan; Siana, Brian; Freeman, William R. +5 more
We measure the ionizing photon production efficiency (ξion) of low-mass galaxies (107.8-109.8 M⊙) at 1.4 < z < 2.7 to better understand the contribution of dwarf galaxies to the ionizing background and reionization. We target galaxies that are magnified by strong-lensing galaxy clusters and use Kec…
Distinguishing between Wet and Dry Atmospheres of TRAPPIST-1 e and f
Rauer, H.; Sánchez-López, A.; López-Puertas, M. +7 more
The nearby TRAPPIST-1 planetary system is an exciting target for characterizing the atmospheres of terrestrial planets. The planets e, f, and g lie in the circumstellar habitable zone and could sustain liquid water on their surfaces. During the extended pre-main-sequence phase of TRAPPIST-1, however, the planets may have experienced extreme water …
Facing problems in the determination of stellar temperatures and gravities: Galactic globular clusters
Bonifacio, P.; Mucciarelli, A.
We analysed red giant branch stars in 16 Galactic globular clusters, computing their atmospheric parameters both from the photometry and from excitation and ionisation balances. The spectroscopic parameters are lower than the photometric ones and this discrepancy increases with decreasing metallicity, reaching differences of ~350 K in effective te…
The signature of primordial black holes in the dark matter halos of galaxies
Hawkins, M. R. S.
Aims: The aim of this paper is to investigate the claim that stars in the lensing galaxy of a gravitationally lensed quasar system can always account for the observed microlensing of the individual quasar images.
Methods: A small sample of gravitationally lensed quasar systems was chosen where the quasar images appear to lie on the fring…
Blasts from the Past: Supernova Shock Breakouts among X-Ray Transients in the XMM-Newton Archive
Alp, Dennis; Larsson, Josefin
The first electromagnetic signal from a supernova (SN) is released when the shock crosses the progenitor surface. This shock breakout (SBO) emission provides constraints on progenitor and explosion properties. Observationally, SBOs appear as minute- to hour-long extragalactic X-ray transients. They are challenging to detect and only one SBO has be…
The First Light Curve Modeling and Orbital Period Change Investigation of Nine Contact Binaries around the Short-period Cutoff
Li, Kai; Xia, Qi-Qi; Gao, Xing +5 more
In this paper, we present the first light curve synthesis and orbital period change analysis of nine contact binaries around the short-period limit. It is found that all these systems are W-subtype contact binaries. One of them is a medium contact system while the others are shallow contact ones. Four of them manifest obvious O'Connell effect expl…
Orbital Parameter Determination for Wide Stellar Binary Systems in the Age of Gaia
Vanderburg, Andrew; Dupuy, Trent J.; Kraus, Adam L. +4 more
The orbits of binary stars and planets, particularly eccentricities and inclinations, encode the angular momentum within these systems. Within stellar multiple systems, the magnitude and (mis)alignment of angular momentum vectors among stars, disks, and planets probes the complex dynamical processes guiding their formation and evolution. The accur…