Search Publications

The Ups and Downs of Accreting X-Ray Pulsars: Decade-long Observations with the Fermi Gamma-Ray Burst Monitor
DOI: 10.3847/1538-4357/ab855c Bibcode: 2020ApJ...896...90M

Wilson-Hodge, C. A.; Roberts, O. J.; Malacaria, C. +4 more

We review more than 10 yr of continuous monitoring of accreting X-ray pulsars with the all-sky Gamma-ray Burst Monitor (GBM) aboard the Fermi Gamma-ray Space Telescope. Our work includes data from the start of GBM operations in 2008 August, through to 2019 November. Pulsations from 39 accreting pulsars are observed over an energy range of 10-50 ke…

2020 The Astrophysical Journal
Gaia 75
Evidence for He I 10830 Å Absorption during the Transit of a Warm Neptune around the M-dwarf GJ 3470 with the Habitable-zone Planet Finder
DOI: 10.3847/1538-4357/ab8559 Bibcode: 2020ApJ...894...97N

Endl, Michael; Mahadevan, Suvrath; Terrien, Ryan +21 more

Understanding the dynamics and kinematics of outflowing atmospheres of hot and warm exoplanets is crucial to understanding the origins and evolutionary history of the exoplanets near the evaporation desert. Recently, ground-based measurements of the meta-stable helium atom's resonant absorption at 10830 Å has become a powerful probe of the base en…

2020 The Astrophysical Journal
Gaia 75
Early Low-mass Galaxies and Star-cluster Candidates at z ∼ 6-9 Identified by the Gravitational-lensing Technique and Deep Optical/Near-infrared Imaging
DOI: 10.3847/1538-4357/ab7dbe Bibcode: 2020ApJ...893...60K

Ono, Yoshiaki; Ouchi, Masami; Charlot, Stéphane +7 more

We present very faint dropout galaxies at z ∼ 6-9 with a stellar mass M down to ${M}_{\star }\sim {10}^{6}\,{M}_{\odot }$ that are found in deep optical/near-infrared (NIR) images of the full data sets of the Hubble Frontier Fields (HFF) program in conjunction with deep ground-based and Spitzer images and gravitational-lensing magnific…

2020 The Astrophysical Journal
eHST 75
A Multifrequency ALMA Characterization of Substructures in the GM Aur Protoplanetary Disk
DOI: 10.3847/1538-4357/ab711e Bibcode: 2020ApJ...891...48H

Wilner, David J.; Andrews, Sean M.; Huang, Jane +12 more

The protoplanetary disk around the T Tauri star GM Aur was one of the first hypothesized to be in the midst of being cleared out by a forming planet. As a result, GM Aur has had an outsized influence on our understanding of disk structure and evolution. We present 1.1 and 2.1 mm ALMA continuum observations of the GM Aur disk at a resolution of ∼50…

2020 The Astrophysical Journal
Gaia 75
COLDz: A High Space Density of Massive Dusty Starburst Galaxies ∼1 Billion Years after the Big Bang
DOI: 10.3847/1538-4357/ab8c48 Bibcode: 2020ApJ...895...81R

Dickinson, Mark; Smail, Ian; Daddi, Emanuele +15 more

We report the detection of CO(J = 2 → 1) emission from three massive dusty starburst galaxies at z > 5 through molecular line scans in the NSF's Karl G. Jansky Very Large Array (VLA) CO Luminosity Density at High Redshift (COLDz) survey. Redshifts for two of the sources, HDF 850.1 (z = 5.183) and AzTEC-3 (z = 5.298), were previously known. We r…

2020 The Astrophysical Journal
eHST 75
Two Ultra-faint Milky Way Stellar Systems Discovered in Early Data from the DECam Local Volume Exploration Survey
DOI: 10.3847/1538-4357/ab6c67 Bibcode: 2020ApJ...890..136M

Bechtol, K.; Zenteno, A.; Allam, S. +56 more

We report the discovery of two ultra-faint stellar systems found in early data from the DECam Local Volume Exploration survey (DELVE). The first system, Centaurus I (DELVE J1238-4054), is identified as a resolved overdensity of old and metal-poor stars with a heliocentric distance of ${\text{}}{D}_{\odot }={116.3}_{-0.6}^{+0.6}\,\mathrm{kpc}$ , a …

2020 The Astrophysical Journal
Gaia 73
Project AMIGA: The Circumgalactic Medium of Andromeda
DOI: 10.3847/1538-4357/aba49c Bibcode: 2020ApJ...900....9L

Brown, Thomas M.; Faucher-Giguère, Claude-André; Hafen, Zachary +22 more

Project AMIGA (Absorption Maps In the Gas of Andromeda) is a survey of the circumgalactic medium (CGM) of Andromeda (M31, ${R}_{\mathrm{vir}}$ ≃ 300 kpc) along 43 QSO sightlines at impact parameters 25 ≤ R ≤ 569 kpc (25 at R ≲ ${R}_{\mathrm{vir}}$). We use ultraviolet absorption measurements of Si II, Si III, Si IV, C II, and C IV from the Hubble …

2020 The Astrophysical Journal
eHST 72
The R-Process Alliance: First Magellan/MIKE Release from the Southern Search for R-process-enhanced Stars
DOI: 10.3847/1538-4357/ab9d1a Bibcode: 2020ApJ...898..150E

Beers, Timothy C.; Placco, Vinicius M.; Hansen, Terese T. +9 more

Extensive progress has recently been made in our understanding of heavy-element production via the r-process in the universe, specifically with the first observed neutron star binary merger (NSBM) event associated with the gravitational-wave signal detected by LIGO, GW170817. The chemical abundance patterns of metal-poor r-process-enhanced stars p…

2020 The Astrophysical Journal
Gaia 71
The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. III. Substructures in Protostellar Disks
DOI: 10.3847/1538-4357/abbad5 Bibcode: 2020ApJ...902..141S

Sheehan, Patrick D.; Megeath, S. Thomas; Looney, Leslie W. +2 more

The prevalence of substructures in ∼1-10 Myr old protoplanetary disks, which are often linked to planet formation, has raised the question of how early such features form and, as a corollary, how early planet formation begins. Here we present observations of seven protostellar disks (aged ∼ 0.1-1 Myr) from the Very Large Array/Atacama Large Millim…

2020 The Astrophysical Journal
Gaia Herschel eHST 70
X-Ray Scaling Relations for a Representative Sample of Planck-selected Clusters Observed with XMM-Newton
DOI: 10.3847/1538-4357/ab7997 Bibcode: 2020ApJ...892..102L

Lovisari, Lorenzo; Andrade-Santos, Felipe; Jones, Christine +7 more

We report the scaling relations derived by fitting the X-ray parameters determined from analyzing the XMM-Newton observations of 120 galaxy clusters in the Planck Early Sunyaev-Zel'dovich (SZ) sample spanning the redshift range of 0.059 < z < 0.546. We find that the slopes of all the investigated scaling relations significantly deviate from …

2020 The Astrophysical Journal
XMM-Newton 69