Search Publications
VIA MACHINAE: Searching for stellar streams using unsupervised machine learning
Buckley, Matthew R.; Shih, David; Necib, Lina +1 more
We develop a new machine learning algorithm, VIA MACHINAE, to identify cold stellar streams in data from the Gaia telescope. VIA MACHINAE is based on ANODE, a general method that uses conditional density estimation and sideband interpolation to detect local overdensities in the data in a model agnostic way. By applying ANODE to the positions, prop…
Close detached white dwarf + brown dwarf binaries: further evidence for low values of the common envelope efficiency
Zorotovic, Monica; Schreiber, MatthiasR
Common envelope evolution is a fundamental ingredient in our understanding of the formation of close binary stars containing compact objects that include the progenitors of type Ia supernovae, short gamma-ray bursts, and most stellar gravitational wave sources. To predict the outcome of common envelope evolution, we still rely to a large degree on…
Discovery of 74 new bright ZZ Ceti stars in the first three years of TESS
Kepler, S. O.; Hermes, J. J.; Bell, Keaton J. +17 more
We report the discovery of 74 new pulsating DA white dwarf stars, or ZZ Cetis, from the data obtained by the Transiting Exoplanet Survey Satellite mission, from Sectors 1 to 39, corresponding to the first 3 cycles. This includes objects from the Southern hemisphere (Sectors 1-13 and 27-39) and the Northern hemisphere (Sectors 14-26), observed with…
Mapping the magnetic field in the Taurus/B211 filamentary cloud with SOFIA HAWC + and comparing with simulation
André, Philippe; Rho, Jeonghee; Li, Pak Shing +4 more
Optical and infrared polarization mapping and recent Planck observations of the filametary cloud L1495 in Taurus show that the large-scale magnetic field is approximately perpendicular to the long axis of the cloud. We use the HAWC + polarimeter on SOFIA to probe the complex magnetic field in the B211 part of the cloud. Our results reveal a disper…
The [O III]λ5007 equivalent width distribution at z 2: the redshift evolution of the extreme emission line galaxies
Maseda, Michael V.; Bunker, Andrew J.; Tang, Mengtao +2 more
We determine the [O III]λ5007 equivalent width (EW) distribution of $1.700\lt \rm {z}\lt 2.274$ rest-frame ultraviolet (UV)-selected (MUV < -19) star-forming galaxies in the GOODS North and South fields. We make use of deep HDUV broad-band photometry catalogues for selection and 3D-HST WFC3/IR grism spectra for measurement of line pr…
Intrinsic tension in the supernova sector of the local Hubble constant measurement and its implications
Hjorth, Jens; Wojtak, Radosław
We reanalyse observations of Type Ia supernovae (SNe) and Cepheids used in the local determination of the Hubble constant and find strong evidence that SN standardization in the calibration sample (galaxies with observed Cepheids) requires a steeper slope of the colour correction than in the cosmological sample (galaxies in the Hubble flow). The c…
Ultra-diffuse galaxies in the perseus cluster: comparing galaxy properties with globular cluster system richness
Forbes, Duncan A.; Romanowsky, Aaron J.; Brodie, Jean P. +6 more
It is clear that within the class of ultra-diffuse galaxies (UDGs), there is an extreme range in the richness of their associated globular cluster (GC) systems. Here, we report the structural properties of five UDGs in the Perseus cluster based on deep Subaru/Hyper Suprime-Cam imaging. Three appear GC-poor and two appear GC-rich. One of our sample…
Milky Way total mass derived by rotation curve and globular cluster kinematics from Gaia EDR3
Hammer, Francois; Wang, Jianling; Yang, Yanbin
Using action-based distribution function for the dynamical model of the Milky Way (MW) we have estimated its total mass and its density profile. Constraints are coming from the globular cluster proper motions from Gaia EDR3, from the rotation curve based on Gaia DR2 data, and from the vertical force data. We use Bayesian Markov chain Monte Carlo m…
Discovery and characterization of five new eclipsing AM CVn systems
Kulkarni, S. R.; Rusholme, B.; Goldstein, D. A. +19 more
AM CVn systems are ultra-compact, hydrogen-depleted, and helium-rich, accreting binaries with degenerate or semidegenerate donors. We report the discovery of five new eclipsing AM CVn systems with orbital periods of 61.5, 55.5, 53.3, 37.4, and 35.4 min. These systems were discovered by searching for deep eclipses in the Zwicky Transient Facility (…
Intermediate- and high-velocity clouds in the Milky Way - II. Evidence for a Galactic fountain with collimated outflows and diffuse inflows
Lehner, Nicolas; Howk, J. Christopher; Marasco, Antonino +1 more
We model the kinematics of the high- and intermediate-velocity clouds (HVCs and IVCs) observed in absorption towards a sample of 55 Galactic halo stars with accurate distance measurements. We employ a simple model of a thick disc whose main free parameters are the gas azimuthal, radial, and vertical velocities (vϕ, vR, and v<…