Search Publications
The HERBAL Model: A Hierarchical Errors-in-variables Bayesian Lognormal Hurdle Model for Galactic Globular Cluster Populations
Speagle, Joshua S.; Harris, William E.; Eadie, Gwendolyn M. +1 more
Galaxy stellar mass is known to be monotonically related to the size of the galaxy's globular cluster (GC) population for Milky Way sized and larger galaxies. However, the relation becomes ambiguous for dwarf galaxies, where there is some evidence for a downturn in GC population size at low galaxy masses. Smaller dwarfs are increasingly likely to …
Quantification of Carbonates, Oxychlorines, and Chlorine Generated by Heterogeneous Electrochemistry Induced by Martian Dust Activity
Olsen, Kevin S.; Wang, Alian; Jackson, Andrew W. +4 more
Heterogeneous electrochemistry induced by Martian dust activity is an important type of atmosphere-surface interaction that affects geochemical processes at the Martian surface and in the Martian atmosphere. We have experimentally demonstrated that heterogeneous electrochemistry stimulated by mid-strength dust events can decompose common chloride …
Observational Detection of Higher-Order Secular Perturbations in Tight Hierarchical Triple Stars
Borkovits, Tamás; Mitnyan, Tibor
In this work, we search for observational evidence of higher-order secular perturbations in three eclipsing binaries. These are slightly eccentric binaries, and they form the inner pairs of tight, compact, hierarchical triple star systems. Simultaneously, we analyze the high-precision satellite (Kepler and TESS) light curves; eclipse timing variat…
A neutron star candidate in the long-period binary 56 UMa
Jorissen, A.; Verschuur, G. L.; Schmelz, J. T. +6 more
Context. 56 UMa is a wide binary system that contains a chemically peculiar red giant and a faint companion. Due to its surface chemical abundances, the red giant was classified as a barium (Ba) star. This implies that the companion has to be a white dwarf, since Ba stars form when mass is transferred to them from an s-process rich Asymptotic Gian…
A Possible Surviving Companion of the SN Ia in the Galactic SNR G272.2-3.2
Galbany, L.; Ruiz-Lapuente, P.; Figueras, F. +4 more
We use the Gaia EDR3 to explore the Galactic supernova remnant (SNR) G272.2-3.2, produced by the explosion of a Type Ia supernova (SN Ia) about 7500 yr ago, to search for a surviving companion. From the abundances in the SNR ejecta, G272.2-3.2 is a normal SN Ia. The Gaia parallaxes allow us to select the stars located within the estimated distance…
Wide binaries demonstrate the consistency of rotational evolution between open cluster and field stars
Gruner, D.; Barnes, S. A.; Janes, K. A.
Context. Gyrochronology enables the derivation of ages of late-type main sequence stars based on their rotation periods and a mass proxy, such as color. It has been explored in open clusters, but a connection to field stars has yet to be successfully established.
Aims: We explore the rotation rates of wide binaries, representing enlightening …
Planetary Orbit Eccentricity Trends (POET). I. The Eccentricity-Metallicity Trend for Small Planets Revealed by the LAMOST-Gaia-Kepler Sample
Zhou, Ji-Lin; Xie, Ji-Wei; Dai, Yuan-Zhe +1 more
Orbital eccentricity is one of the basic planetary properties, whose distribution may shed light on the history of planet formation and evolution. Here, in a series of works on Planetary Orbit Eccentricity Trends (dubbed POET), we study the distribution of planetary eccentricities and their dependence on stellar/planetary properties. In this paper…
TOI 560: Two Transiting Planets Orbiting a K Dwarf Validated with iSHELL, PFS, and HIRES RVs
Deming, Drake; Gorjian, Varoujan; Hellier, Coel +93 more
We validate the presence of a two-planet system orbiting the 0.15-1.4 Gyr K4 dwarf TOI 560 (HD 73583). The system consists of an inner moderately eccentric transiting mini-Neptune (TOI 560 b, $P={6.3980661}_{-0.0000097}^{+0.0000095}$ days, $e={0.294}_{-0.062}^{+0.13}$ , $M={0.94}_{-0.23}^{+0.31}{M}_{\mathrm{Nep}}$ ) initially discovered in the Sec…
Multiwavelength scrutiny of X-ray sources in dwarf galaxies: ULXs versus AGNs
Soria, Roberto; Greene, Jenny E.; Baldassare, Vivienne F. +10 more
Owing to their quiet evolutionary histories, nearby dwarf galaxies (stellar masses $M_\star \lesssim 3 \times 10^9 \, \mathrm{M}_\odot$) have the potential to teach us about the mechanism(s) that 'seeded' the growth of supermassive black holes, and also how the first stellar mass black holes formed and interacted with their environments. Here, we …
Asteroseismic age constraints on the open cluster NGC 2477 using oscillating stars identified with TESS FFI
Creevey, O. L.; Palakkatharappil, D. B.
Context. Asteroseismology is one of the few methods to derive ages of individual stars due to the high precision of their observations. Isochrone fitting is a powerful alternative method for deriving ages by studying clusters of stars. Pulsating stars in clusters should therefore allow for detailed studies of the stellar models.
Aims: Our obj…