Search Publications
A Comprehensive Spectroscopic and Photometric Analysis of DA and DB White Dwarfs from SDSS and Gaia
Genest-Beaulieu, C.; Bergeron, P.
We present a detailed spectroscopic and photometric analysis of DA and DB white dwarfs drawn from the Sloan Digital Sky Survey with trigonometric parallax measurements available from the Gaia mission. The temperature and mass scales obtained from fits to ugriz photometry appear reasonable for both DA and DB stars, with almost identical mean masses…
MAGPHYS+photo-z: Constraining the Physical Properties of Galaxies with Unknown Redshifts
Daddi, E.; Salvato, M.; Vaccari, M. +8 more
We present an enhanced version of the multiwavelength spectral modeling code MAGPHYS that allows the estimation of galaxy photometric redshift and physical properties (e.g., stellar mass, star formation rate, dust attenuation) simultaneously, together with robust characterization of their uncertainties. The self-consistent modeling over ultraviole…
Half-mass Radii of Quiescent and Star-forming Galaxies Evolve Slowly from 0 ≲ z ≤ 2.5: Implications for Galaxy Assembly Histories
Barro, Guillermo; Kriek, Mariska; Price, Sedona H. +1 more
We use high-resolution, multiband imaging of ∼16,500 galaxies in the CANDELS fields at 0 ≲ z ≤ 2.5 to study the evolution of color gradients and half-mass radii over cosmic time. We find that galaxy color gradients at fixed mass evolve rapidly between z ∼ 2.5 and z ∼ 1, but remain roughly constant below z ∼ 1. This result implies that the sizes of…
A Model-independent Mass and Moderate Eccentricity for β Pic b
Kratter, Kaitlin M.; Dupuy, Trent J.; Bowler, Brendan P. +1 more
We use a cross-calibration of Hipparcos and Gaia second data release astrometry for β Pic to measure the mass of the giant planet β Pic b (13 ± 3 {M}Jup}) in a comprehensive joint orbit analysis that includes published relative astrometry and radial velocities. Our mass uncertainty is somewhat higher than previous work because our astro…
On High-energy Particles in Accretion Disk Coronae of Supermassive Black Holes: Implications for MeV Gamma-rays and High-energy Neutrinos from AGN Cores
Inoue, Susumu; Inoue, Yoshiyuki; Doi, Akihiro +1 more
Recent observations with ALMA have revealed evidence for nonthermal synchrotron emission from the core regions of two nearby Seyfert galaxies. This suggests that the coronae of accretion disks in active galactic nuclei (AGNs) can be conducive to the acceleration of nonthermal electrons, in addition to the hot, thermal electrons responsible for the…
Kinematic Detections of Protoplanets: A Doppler Flip in the Disk of HD 100546
Pérez, Sebastián; Casassus, Simon
Protoplanets and circumplanetary disks are rather elusive in their thermal IR emission. Yet they are cornerstones to the most popular interpretations for the protoplanetary disk structures observed in the gas and dust density fields, even though alternative theories exist. The gaseous velocity field should also bear the imprint of planet-disk inte…
In the Galactic Disk, Stellar [Fe/H] and Age Predict Orbits and Precise [X/Fe]
Rix, H. -W.; Hawkins, K.; Bird, J. C. +4 more
We explore the structure of the element abundance-age-orbit distribution of the stars in the Milky Way’s low-α disk, by (re-)deriving precise [Fe/H], [X/Fe], and ages, along with orbits, for red clump stars from the APOGEE survey. There has been a long-standing theoretical expectation and observational evidence that metallicity ([Fe/H]) and age ar…
Near-infrared Spectroscopy of Galaxies During Reionization: Measuring C III] in a Galaxy at z = 7.5
Papovich, Casey; Finkelstein, Steven L.; Dickinson, Mark +9 more
We present Keck/MOSFIRE H-band spectroscopy targeting C III] λ1907, 1909 in a z = 7.5056 galaxy previously identified via Lyα emission. We detect strong line emission at 1.621+/- 0.002 µ {{m}} with a line flux of (2.63 ± 0.52) × 10-18 erg s-1 cm-2. We tentatively identify this line as [C III] λ1907, but we ar…
Molecular and Ionized Gas Phases of an AGN-driven Outflow in a Typical Massive Galaxy at z ≈ 2
Lutz, D.; Wuyts, S.; Genzel, R. +22 more
Nuclear outflows driven by accreting massive black holes are one of the main feedback mechanisms invoked at high-z to reproduce the distinct separation between star-forming disk galaxies and quiescent spheroidal systems. Yet our knowledge of feedback at high-z remains limited by the lack of observations of the multiple gas phases in galaxy outflow…
First Resolution of Microlensed Images
Kochanek, C. S.; Gould, Andrew; Stanek, K. Z. +12 more
We employ Very Large Telescope Interferometer GRAVITY to resolve, for the first time, the two images generated by a gravitational microlens. The measurements of the image separation {{Δ }}{θ }-,+=3.78+/- 0.05 mas, and hence the Einstein radius θ E = 1.87 ± 0.03 mas, are precise. This demonstrates the robustness of the method,…