Search Publications
High-redshift AGN in the Chandra Deep Fields: the obscured fraction and space density of the sub-L* population
Lehmer, B. D.; Brandt, W. N.; Vignali, C. +14 more
We investigate the population of high-redshift (3 ≤ z < 6) active galactic nuclei (AGN) selected in the two deepest X-ray surveys, the 7 Ms Chandra Deep Field-South and 2 Ms Chandra Deep Field-North. Their outstanding sensitivity and spectral characterization of faint sources allow us to focus on the sub-L* regime (logLX ≲…
Modelling Quasi-Periodic Pulsations in Solar and Stellar Flares
Nakariakov, V. M.; Jelínek, P.; McLaughlin, J. A. +2 more
Solar flare emission is detected in all EM bands and variations in flux density of solar energetic particles. Often the EM radiation generated in solar and stellar flares shows a pronounced oscillatory pattern, with characteristic periods ranging from a fraction of a second to several minutes. These oscillations are referred to as quasi-periodic p…
275 Candidates and 149 Validated Planets Orbiting Bright Stars in K2 Campaigns 0-10
Vanderburg, Andrew; Bieryla, Allyson; Latham, David W. +25 more
Since 2014, NASA’s K2 mission has observed large portions of the ecliptic plane in search of transiting planets and has detected hundreds of planet candidates. With observations planned until at least early 2018, K2 will continue to identify more planet candidates. We present here 275 planet candidates observed during Campaigns 0-10 of the K2 miss…
Reanalysis of the Gaia Data Release 2 photometric sensitivity curves using HST/STIS spectrophotometry
Weiler, M.; Maíz Apellániz, J.
Context. The second data release (DR2) from the European Space Agency mission Gaia took place on April 2018. DR2 included photometry for more than 1.3 × 109 sources in the three bands G, GBP, and GRP. Even though the Gaia DR2 photometry is very precise, there are currently three alternative definitions of the sensi…
Constraining the mass and radius of neutron stars in globular clusters
Heinke, C. O.; Ho, W. C. G.; Bogdanov, S. +4 more
We analyse observations of eight quiescent low-mass X-ray binaries in globular clusters and combine them to determine the neutron star mass-radius curve and the equation of state of dense matter. We determine the effect that several uncertainties may have on our results, including uncertainties in the distance, the atmosphere composition, the neut…
The Updated Multiple Star Catalog
Tokovinin, Andrei
The catalog of hierarchical stellar systems with three or more components is an update of the original 1997 version. For 2000 hierarchies, the new Multiple Star Catalog (MSC) provides distances, component masses and periods, and supplementary information (astrometry, photometry, identifiers, orbits, notes). The MSC content and format are explained…
Clarifying the Hubble constant tension with a Bayesian hierarchical model of the local distance ladder
Feeney, Stephen M.; Mortlock, Daniel J.; Dalmasso, Niccolò
Estimates of the Hubble constant, H0, from the local distance ladder and from the cosmic microwave background (CMB) are discrepant at the ∼3σ level, indicating a potential issue with the standard Λ cold dark matter (ΛCDM) cosmology. A probabilistic (i.e. Bayesian) interpretation of this tension requires a model comparison calculation, w…
Strong-lensing analysis of A2744 with MUSE and Hubble Frontier Fields images
Inami, H.; Schmidt, K.; Mahler, G. +13 more
We present an analysis of Multi Unit Spectroscopic Explorer (MUSE) observations obtained on the massive Frontier Fields (FFs) cluster A2744. This new data set covers the entire multiply imaged region around the cluster core. The combined catalogue consists of 514 spectroscopic redshifts (with 414 new identifications). We use this redshift informat…
Gaia Proper Motions and Orbits of the Ultra-faint Milky Way Satellites
Simon, Joshua D.
The second data release from the Gaia mission (DR2) provides a comprehensive and unprecedented picture of the motions of astronomical sources in the plane of the sky, extending from the solar neighborhood to the outer reaches of the Milky Way. I present proper-motion measurements based on Gaia DR2 for 17 ultra-faint dwarf galaxies within 100 kpc o…
Measuring Dark Energy Properties with Photometrically Classified Pan-STARRS Supernovae. II. Cosmological Parameters
Berger, E.; Kirshner, R. P.; Rest, A. +25 more
We use 1169 Pan-STARRS supernovae (SNe) and 195 low-z (z < 0.1) SNe Ia to measure cosmological parameters. Though most Pan-STARRS SNe lack spectroscopic classifications, in a previous paper we demonstrated that photometrically classified SNe can be used to infer unbiased cosmological parameters by using a Bayesian methodology that marginalizes …