Search Publications
Missions
Journals
Publication Years
Mapping Metallicity Variations across Nearby Galaxy Disks
Chevance, M.; Meidt, S. E.; Schinnerer, E. +21 more
The distribution of metals within a galaxy traces the baryon cycle and the buildup of galactic disks, but the detailed gas phase metallicity distribution remains poorly sampled. We have determined the gas phase oxygen abundances for 7138 H II regions across the disks of eight nearby galaxies using Very Large Telescope/Multi Unit Spectroscopic Expl…
A stellar census in globular clusters with MUSE: Binaries in NGC 3201
Brinchmann, Jarle; Weilbacher, Peter M.; Kamann, Sebastian +8 more
We utilise multi-epoch MUSE spectroscopy to study binary stars in the core of the Galactic globular cluster NGC 3201. Our sample consists of 3553 stars with 54 883 spectra in total comprising 3200 main-sequence stars up to 4 magnitudes below the turn-off. Each star in our sample has between 3 and 63 (with a median of 14) reliable radial velocity m…
The mass of the Milky Way from satellite dynamics
Grand, Robert J. J.; Gómez, Facundo A.; Marinacci, Federico +6 more
We present and apply a method to infer the mass of the Milky Way (MW) by comparing the dynamics of MW satellites to those of model satellites in the EAGLE cosmological hydrodynamics simulations. A distribution function (DF) for galactic satellites is constructed from EAGLE using specific angular momentum and specific energy, which are scaled so as…
Constraining Primordial Black Hole Abundance with the Galactic 511 keV Line
DeRocco, William; Graham, Peter W.
Models in which dark matter consists entirely of primordial black holes (PBHs) with masses around 1 017 g are currently unconstrained. However, if PBHs are a component of the Galactic dark matter density, they will inject a large flux of energetic particles into the Galaxy as they radiate. Positrons produced by these black holes will su…
Do Kepler Superflare Stars Really Include Slowly Rotating Sun-like Stars?—Results Using APO 3.5 m Telescope Spectroscopic Observations and Gaia-DR2 Data
Notsu, Yuta; Maehara, Hiroyuki; Namekata, Kosuke +7 more
We report the latest view of Kepler solar-type (G-type main-sequence) superflare stars, including recent updates with Apache Point Observatory (APO) 3.5 m telescope spectroscopic observations and Gaia-DR2 data. First, we newly conducted APO 3.5 m spectroscopic observations of 18 superflare stars found from Kepler 1-minute time-cadence data. More t…
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…