Search Publications
The Solar Cycle
Hathaway, David H.
The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejectio…
Galaxy Clusters Discovered via the Sunyaev-Zel'dovich Effect in the 2500-Square-Degree SPT-SZ Survey
Gladders, M. D.; Schrabback, T.; Rest, A. +71 more
We present a catalog of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect signature from 2500 deg2 of South Pole Telescope (SPT) data. This work represents the complete sample of clusters detected at high significance in the 2500 deg2 SPT-SZ survey, which was completed in 2011. A total of 677 (409) cluster can…
Powerful Outflows and Feedback from Active Galactic Nuclei
Pounds, Ken; King, Andrew
Active galactic nuclei (AGNs) represent the growth phases of the supermassive black holes in the center of almost every galaxy. Powerful, highly ionized winds, with velocities â¼0.1-0.2c, are a common feature in X-ray spectra of luminous AGNs, offering a plausible physical origin for the well-known connections between the hole and properties of it…
How to Constrain Your M Dwarf: Measuring Effective Temperature, Bolometric Luminosity, Mass, and Radius
Gaidos, Eric; Mann, Andrew W.; von Braun, Kaspar +2 more
Precise and accurate parameters for late-type (late K and M) dwarf stars are important for characterization of any orbiting planets, but such determinations have been hampered by these stars’ complex spectra and dissimilarity to the Sun. We exploit an empirically calibrated method to estimate spectroscopic effective temperature (Teff) a…
Combined CO and Dust Scaling Relations of Depletion Time and Molecular Gas Fractions with Cosmic Time, Specific Star-formation Rate, and Stellar Mass
Berta, S.; Magnelli, B.; Lutz, D. +33 more
We combine molecular gas masses inferred from CO emission in 500 star-forming galaxies (SFGs) between z = 0 and 3, from the IRAM-COLDGASS, PHIBSS1/2, and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512 galaxy stacks over the same stellar mass/redshift range. We constrain the scaling relations of molecular gas d…
The KMOS3D Survey: Design, First Results, and the Evolution of Galaxy Kinematics from 0.7 <= z <= 2.7
Wuyts, E.; Lutz, D.; Wuyts, S. +24 more
We present the KMOS3D survey, a new integral field survey of over 600 galaxies at 0.7 < z < 2.7 using KMOS at the Very Large Telescope. The KMOS3D survey utilizes synergies with multi-wavelength ground- and space-based surveys to trace the evolution of spatially resolved kinematics and star formation from a homogeneous …
Forty-seven Milky Way-sized, Extremely Diffuse Galaxies in the Coma Cluster
van Dokkum, Pieter G.; Conroy, Charlie; Abraham, Roberto +3 more
We report the discovery of 47 low surface brightness objects in deep images of a 3° × 3° field centered on the Coma cluster, obtained with the Dragonfly Telephoto Array. The objects have central surface brightness µ(g, 0) ranging from 24-26 mag arcsec-2 and effective radii r eff = 3''-10'', as measured from archival Can…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. I. Overview of the Project and Detection of Multiple Stellar Populations
Dalessandro, E.; Salaris, M.; Anderson, J. +24 more
In this paper we describe a new UV-initiative Hubble Space Telescope project (GO-13297) that will complement the existing F606W and F814W database of the Advanced Camera for Surveys Globular Cluster (GC) Treasury by imaging most of its clusters through UV/blue WFC3/UVIS filters F275W, F336W, and F438W. This “magic trio” of filters has shown an unc…
A Three-dimensional Map of Milky Way Dust
Tonry, John; Rix, Hans-Walter; Magnier, Eugene +13 more
We present a three-dimensional map of interstellar dust reddening, covering three-quarters of the sky out to a distance of several kiloparsecs, based on Pan-STARRS 1 (PS1) and 2MASS photometry. The map reveals a wealth of detailed structure, from filaments to large cloud complexes. The map has a hybrid angular resolution, with most of the map at a…
Estimating Distances from Parallaxes
Bailer-Jones, Coryn A. L.
Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that doing this is not trivial once the fractional parallax error is larger than about 20%, which will be the case f…