Search Publications

The COS CGM Compendium. III. Metallicity and Physical Properties of the Cool Circumgalactic Medium at z ≲ 1
DOI: 10.3847/1538-4357/ab41fd Bibcode: 2019ApJ...887....5L

Lehner, Nicolas; Howk, J. Christopher; O'Meara, John M. +3 more

We characterize the metallicities and physical properties of cool, photoionized gas in a sample of 152 z ≲ 1 strong Lyα forest systems (SLFSs, absorbers with 15 < log N H I < 16.2). The sample is drawn from our Cosmic Origins Spectrograph (COS) circumgalactic medium compendium (CCC), an ultraviolet survey of H I-selected circumga…

2019 The Astrophysical Journal
eHST 54
Varstrometry for Off-nucleus and Dual Sub-Kpc AGN (VODKA): How Well Centered Are Low-z AGN?
DOI: 10.3847/2041-8213/ab4b54 Bibcode: 2019ApJ...885L...4S

Shen, Yue; Hwang, Hsiang-Chih; Liu, Xin +1 more

Off-nucleus active galactic nuclei (AGN) can be signposts of inspiraling supermassive black holes (SMBHs) on galactic scales, or accreting SMBHs recoiling after the coalescence of an SMBH binary or slingshot from three-body interactions. Because of the stochastic variability of AGN, the measured photocenter of an unresolved AGN-host system will di…

2019 The Astrophysical Journal
Gaia 54
Diagnosing solar wind origins using in situ measurements in the inner heliosphere
DOI: 10.1093/mnras/sty2814 Bibcode: 2019MNRAS.482.1706S

Matteini, L.; Horbury, T. S.; Stansby, D.

Robustly identifying the solar sources of individual packets of solar wind measured in interplanetary space remains an open problem. We set out to see if this problem is easier to tackle using solar wind measurements closer to the Sun than 1 au, where the mixing and dynamical interaction of different solar wind streams is reduced. Using measuremen…

2019 Monthly Notices of the Royal Astronomical Society
SolarOrbiter 54
Mapping the Northern Galactic Disk Warp with Classical Cepheids
DOI: 10.32023/0001-5237/69.4.1 Bibcode: 2019AcA....69..305S

Soszyński, I.; Udalski, A.; Szymański, M. K. +11 more

We present an updated three dimensional map of the Milky Way based on a sample of 2431 classical Cepheid variable stars, supplemented with about 200 newly detected classical Cepheids from the OGLE survey. The new objects were discovered as a result of a dedicated observing campaign of the ≈280 square degree extension of the OGLE footprint of the G…

2019 Acta Astronomica
Gaia 54
An Initial Overview of the Extent and Structure of Recent Star Formation within the Serpens Molecular Cloud Using Gaia Data Release 2
DOI: 10.3847/1538-4357/ab1d67 Bibcode: 2019ApJ...878..111H

Herczeg, Gregory J.; Jose, Jessy; Johnstone, Doug +7 more

The dense clusters within the Serpens Molecular Cloud are among the most active regions of nearby star formation. In this paper, we use Gaia DR2 parallaxes and proper motions to statistically measure ∼1167 kinematic members of Serpens, few of which have been previously identified, to evaluate the star formation history of the complex. The optical …

2019 The Astrophysical Journal
Gaia 53
Star-forming content of the giant molecular filaments in the Milky Way
DOI: 10.1051/0004-6361/201732400 Bibcode: 2019A&A...622A..52Z

Henning, Th.; Zhang, M.; Fang, M. +2 more

Context. Through observations numerous giant molecular filaments (GMFs) have been discovered in the Milky Way. Their role in the Galactic star formation and Galaxy-scale evolution of dense gas is unknown.
Aims: We investigate systematically the star-forming content of all currently known GMFs. This allows us to estimate the star formation rat…

2019 Astronomy and Astrophysics
Herschel 53
A Gaia-Enceladus Analog in the EAGLE Simulation: Insights into the Early Evolution of the Milky Way
DOI: 10.3847/2041-8213/ab3e0e Bibcode: 2019ApJ...883L...5B

Helmi, Amina; Tissera, Patricia B.; Bignone, Lucas A.

We identify a simulated Milky Way analog in the EAGLE suite of cosmological hydrodynamical simulations. This galaxy not only shares similar global properties as the Milky Way, but was specifically selected because its merger history resembles that currently known for the Milky Way. In particular we find that this Milky Way analog has experienced i…

2019 The Astrophysical Journal
Gaia 53
Evidence for the Third Stellar Population in the Milky Way’s Disk
DOI: 10.3847/1538-4357/ab517c Bibcode: 2019ApJ...887...22C

Beers, Timothy C.; Lee, Young Sun; Carollo, Daniela +6 more

The Milky Way is a unique laboratory in which stellar properties can be measured and analyzed in detail. In particular, stars in the older populations encode information on the mechanisms that led to the formation of our Galaxy. In this article, we analyze the kinematics, spatial distribution, and chemistry of a large number of stars in the solar …

2019 The Astrophysical Journal
Gaia 53
A discontinuity in the Teff-radius relation of M-dwarfs
DOI: 10.1093/mnras/sty3430 Bibcode: 2019MNRAS.484.2674R

Jordán, Andrés; Espinoza, Néstor; Brahm, Rafael +7 more

We report on 13 new high-precision measurements of stellar diameters for low-mass dwarfs obtained by means of near-infrared long-baseline interferometry with PIONIER at the Very Large Telescope Interferometer. Together with accurate parallaxes from Gaia DR2, these measurements provide precise estimates for their linear radii, effective temperature…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 53
Clouds in arms
DOI: 10.1093/mnrasl/sly178 Bibcode: 2019MNRAS.482L...9B

Belokurov, Vasily A.; Erkal, Denis

We use astrometry and broad-band photometry from Data Release 2 of the ESA's Gaia mission to map out low surface-brightness features in the stellar density distribution around the Large and Small Magellanic Clouds. The LMC appears to have grown two thin and long stellar streams in its Northern and Southern regions, highly reminiscent of spiral arm…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 53