Search Publications
Kepler Planet Occurrence Rates for Mid-type M Dwarfs as a Function of Spectral Type
Muirhead, Philip S.; Cushing, Michael C.; Christiansen, Jessie L. +1 more
Previous studies of planet occurrence rates largely relied on photometric stellar characterizations. In this paper, we present planet occurrence rates for mid-type M dwarfs using spectroscopy, parallaxes, and photometry to determine stellar characteristics. Our spectroscopic observations have allowed us to constrain spectral type, temperatures, an…
Primordial black holes from inflation with nonminimal derivative coupling
Wu, Puxun; Yu, Hongwei; Fu, Chengjie
We propose a novel enhancement mechanism of the curvature perturbations in the nonminimal derivative coupling inflation model with a coupling parameter related to the inflaton field. By considering a special form of the coupling parameter as a function of the inflaton, a period of ultra-slow-roll inflation can be realized due to the gravitationall…
The Streams of the Gaping Abyss: A Population of Entangled Stellar Streams Surrounding the Inner Galaxy
Malhan, Khyati; Ibata, Rodrigo A.; Martin, Nicolas F.
We present the discovery of a large population of stellar streams that surround the inner Galaxy, found in the Gaia DR2 catalog using the new STREAMFINDER algorithm. Here we focus on the properties of eight new high-significance structures found at heliocentric distances between 1 and 10 kpc and at Galactic latitudes | b| > 20^\circ , named Sli…
Elemental and molecular abundances in comet 67P/Churyumov-Gerasimenko
Mall, Urs; De Keyser, Johan; Hansen, Kenneth C. +18 more
Comets are considered to be some of the most pristine and unprocessed Solar system objects accessible to in situ exploration. Investigating their molecular and elemental composition takes us on a journey back to the early period of our Solar system and possibly even further. In this work, we deduce the bulk abundances of the major volatile species…
The ASAS-SN catalogue of variable stars III: variables in the southern TESS continuous viewing zone
Kochanek, C. S.; Stanek, K. Z.; Dong, Subo +13 more
The All-Sky Automated Survey for Supernovae (ASAS-SN) provides long-baseline (∼4 yr) light curves for sources brighter than V ≲ 17 mag across the whole sky. The Transiting Exoplanet Survey Satellite (TESS) has started to produce high-quality light curves with a baseline of at least 27 d, eventually for most of the sky. The combination of ASAS-SN a…
Constraining the Neutron Star Mass-Radius Relation and Dense Matter Equation of State with NICER. I. The Millisecond Pulsar X-Ray Data Set
Steiner, James F.; Remillard, Ronald A.; Enoto, Teruaki +27 more
We present the set of deep Neutron Star Interior Composition Explorer (NICER) X-ray timing observations of the nearby rotation-powered millisecond pulsars PSRs J0437-4715, J0030+0451, J1231-1411, and J2124-3358, selected as targets for constraining the mass-radius relation of neutron stars and the dense matter equation of state (EoS) via modeling …
Non-thermal pressure support in X-COP galaxy clusters
Pointecouteau, E.; Rossetti, M.; Rasia, E. +13 more
Galaxy clusters are the endpoints of structure formation and are continuously growing through the merging and accretion of smaller structures. Numerical simulations predict that a fraction of their energy content is not yet thermalized, mainly in the form of kinetic motions (turbulence, bulk motions). Measuring the level of non-thermal pressure su…
Gaia Data Release 2. Variable stars in the colour-absolute magnitude diagram
Prusti, T.; Mazeh, T.; Zucker, S. +453 more
Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G ≲ 21 mag.
Aims: We showcase stellar variability in the Galactic colour-absolute magnitude diagram (CaMD). We focus on pulsating, eruptive, and cataclysmic variables, as well as on stars that exhibit variability that is due to rotation a…
Simultaneous calibration of spectro-photometric distances and the Gaia DR2 parallax zero-point offset with deep learning
Bovy, Jo; Leung, Henry W.
Gaia measures the five astrometric parameters for stars in the Milky Way, but only four of them (positions and proper motion, but not distance) are well measured beyond a few kpc from the Sun. Modern spectroscopic surveys such as APOGEE cover a large area of the Milky Way disc and we can use the relation between spectra and luminosity to determine…
The afterglow and kilonova of the short GRB 160821B
Troja, E.; Cenko, S. B.; Sakamoto, T. +24 more
GRB 160821B is a short duration gamma-ray burst (GRB) detected and localized by the Neil Gehrels Swift Observatory in the outskirts of a spiral galaxy at z = 0.1613, at a projected physical offset of 16 kpc from the galaxy's center. We present X-ray, optical/nIR, and radio observations of its counterpart and model them with two distinct components…