Search Publications

The evolution of galaxy shapes in CANDELS: from prolate to discy
DOI: 10.1093/mnras/stz339 Bibcode: 2019MNRAS.484.5170Z

Faber, S. M.; Lin, Lin; Zhang, Haowen +9 more

We model the projected b/a-log a distributions of CANDELS star-forming main-sequence galaxies, where a (b) is the half-light semimajor (semiminor) axis of the galaxy images measured by GALFIT. We find that smaller a galaxies are rounder at all stellar masses M* and redshifts, so we include a when analysing b/a distributions. Approximati…

2019 Monthly Notices of the Royal Astronomical Society
eHST 68
CLEAR. I. Ages and Metallicities of Quiescent Galaxies at 1.0 < z < 1.8 Derived from Deep Hubble Space Telescope Grism Data
DOI: 10.3847/1538-4357/aaf22e Bibcode: 2019ApJ...870..133E

Papovich, Casey; Dickinson, Mark; Giavalisco, Mauro +14 more

We use deep Hubble Space Telescope spectroscopy to constrain the metallicities and (light-weighted) ages of massive ({log}{M}* /{M}≳ 10) galaxies selected to have quiescent stellar populations at 1.0 < z < 1.8. The data include twelve-orbit depth coverage with the WFC3/G102 grism covering ∼8000 < λ < 11,500 Å at…

2019 The Astrophysical Journal
eHST 68
SkyMapper stellar parameters for Galactic Archaeology on a grand-scale
DOI: 10.1093/mnras/sty2878 Bibcode: 2019MNRAS.482.2770C

Wolf, C.; Yong, D.; Casagrande, L. +3 more

The SkyMapper photometric surveys provides uvgriz photometry for several millions sources in the Southern sky. We use DR1.1 to explore the quality of its photometry, and develop a formalism to homogenize zero-points across the sky using stellar effective temperatures. Physical flux transformations, and zero-points appropriate for this release are …

2019 Monthly Notices of the Royal Astronomical Society
Gaia 68
The wide binary fraction of solar-type stars: emergence of metallicity dependence at a < 200 au
DOI: 10.1093/mnrasl/sly206 Bibcode: 2019MNRAS.482L.139E

Rix, Hans-Walter; El-Badry, Kareem

We combine a catalogue of wide binaries constructed from Gaia DR2 with [Fe/H] abundances from wide-field spectroscopic surveys to quantify how the binary fraction varies with metallicity over separations 50 ≲ s/au ≲ 50 000. At a given distance, the completeness of the catalogue is independent of metallicity, making it straightforward to constrain …

2019 Monthly Notices of the Royal Astronomical Society
Gaia 68
A hypervelocity star with a Magellanic origin
DOI: 10.1093/mnras/sty2674 Bibcode: 2019MNRAS.483.2007E

Boubert, Douglas; Erkal, Denis; Evans, N. Wyn +2 more

Using proper motion measurements from Gaia Data Release 2, we probe the origin of 26 previously known hypervelocity stars (HVSs) around the Milky Way. We find that a significant fraction of these stars have a high probability of originating in the Milky Way Galaxy, but there is one obvious outlier. HVS3 is highly likely to be coming almost from th…

2019 Monthly Notices of the Royal Astronomical Society
Gaia eHST 67
Recovering Thermodynamics from Spectral Profiles observed by IRIS: A Machine and Deep Learning Approach
DOI: 10.3847/2041-8213/ab15d9 Bibcode: 2019ApJ...875L..18S

De Pontieu, Bart; Gošić, Milan; Sainz Dalda, Alberto +1 more

Inversion codes allow the reconstruction of a model atmosphere from observations. With the inclusion of optically thick lines that form in the solar chromosphere, such modeling is computationally very expensive because a non-LTE evaluation of the radiation field is required. In this study, we combine the results provided by these traditional metho…

2019 The Astrophysical Journal
IRIS 67
New Constraints From Dust Lines on the Surface Densities of Protoplanetary Disks
DOI: 10.3847/1538-4357/ab20ce Bibcode: 2019ApJ...878..116P

Murray-Clay, Ruth; Pérez, Laura M.; Powell, Diana +2 more

We present new determinations of disk surface density, independent of an assumed dust opacity, for a sample of seven bright, diverse, protoplanetary disks using measurements of disk dust lines. We develop a robust method for determining the location of dust lines by modeling disk interferometric visibilities at multiple wavelengths. The disks in o…

2019 The Astrophysical Journal
Gaia 67
Revealing the Stellar Mass and Dust Distributions of Submillimeter Galaxies at Redshift 2
DOI: 10.3847/1538-4357/ab1f77 Bibcode: 2019ApJ...879...54L

Thomson, A. P.; Magnelli, B.; Ivison, R. J. +35 more

We combine high-resolution ALMA and HST/CANDELS observations of 20 submillimeter galaxies (SMGs), predominantly from the AS2UDS survey at z ≃ 2, with bright rest-frame optical counterparts ({K}{{s}}≲ 22.9) to investigate the resolved structural properties of their dust and stellar components. We derive two-dimensional stellar-mass distr…

2019 The Astrophysical Journal
eHST 67
High-resolution ALMA Observations of HD 100546: Asymmetric Circumstellar Ring and Circumplanetary Disk Upper Limits
DOI: 10.3847/1538-4357/aaf389 Bibcode: 2019ApJ...871...48P

Pineda, Jaime E.; Testi, Leonardo; Garufi, Antonio +7 more

We present long-baseline Atacama Large Millimeter/submillimeter Array observations of the 870 µm dust continuum emission and CO (3-2) from the protoplanetary disk around the Herbig Ae/Be star HD 100546, which is one of the few systems claimed to have two young embedded planets. These observations achieve a resolution of 4 au (3.8 mas), an rm…

2019 The Astrophysical Journal
Gaia 67
The remarkable X-ray variability of IRAS 13224-3809 - I. The variability process
DOI: 10.1093/mnras/sty2527 Bibcode: 2019MNRAS.482.2088A

Young, A. J.; Fabian, A. C.; Reynolds, C. S. +17 more

We present a detailed X-ray timing analysis of the highly variable narrow-line Seyfert 1 (NLS1) galaxy IRAS 13224-3809. The source was recently monitored for 1.5 Ms with XMM-Newton, which, combined with 500 ks archival data, makes this the best-studied NLS1 galaxy in X-rays to date. We apply standard time- and Fourier-domain techniques in order to…

2019 Monthly Notices of the Royal Astronomical Society
XMM-Newton 67