Search Publications
The Gould’s Belt Distances Survey (GOBELINS). V. Distances and Kinematics of the Perseus Molecular Cloud
Kounkel, Marina; Rodríguez, Luis F.; Loinard, Laurent +10 more
We derive the distance and structure of the Perseus molecular cloud by combining trigonometric parallaxes from Very Long Baseline Array (VLBA) observations, taken as part of the GOBELINS survey and Gaia Data Release 2. Based on our VLBA astrometry, we obtain a distance of 321 ± 10 pc for IC 348. This is fully consistent with the mean distance of 3…
A Precise Distance to the Host Galaxy of the Binary Neutron Star Merger GW170817 Using Surface Brightness Fluctuations
Covino, S.; D'Avanzo, P.; Lyman, J. D. +25 more
The joint detection of gravitational waves (GWs) and electromagnetic radiation from the binary neutron star (BNS) merger GW170817 has provided unprecedented insight into a wide range of physical processes: heavy element synthesis via the r-process; the production of relativistic ejecta; the equation of state of neutron stars and the nature of the …
Spectroscopic Observations of Current Sheet Formation and Evolution
Warren, Harry P.; Doschek, George A.; Ugarte-Urra, Ignacio +3 more
We report on the structure and evolution of a current sheet that formed in the wake of an eruptive X8.3 flare observed at the west limb of the Sun on 2017 September 10. Using observations from the EUV Imaging Spectrometer (EIS) on Hinode and the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory, we find that plasma in the curren…
Dust Attenuation, Bulge Formation, and Inside-out Quenching of Star Formation in Star-forming Main Sequence Galaxies at z ∼ 2
Wuyts, S.; Förster Schreiber, N. M.; Genzel, R. +10 more
We derive 2D dust attenuation maps at ∼1 kpc resolution from the UV continuum for 10 galaxies on the z ∼ 2 star-forming main sequence (SFMS). Comparison with IR data shows that 9 out of 10 galaxies do not require further obscuration in addition to the UV-based correction, though our sample does not include the most heavily obscured, massive galaxi…
Revival of the Magnetar PSR J1622-4950: Observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
Tasse, C.; Camilo, F.; Stappers, B. +205 more
New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100× larger than during its dormant state. The X-ray flu…
Accretion Disk Reverberation with Hubble Space Telescope Observations of NGC 4593: Evidence for Diffuse Continuum Lags
Horne, Keith; Goad, Michael R.; Korista, Kirk T. +4 more
The Seyfert 1 galaxy NGC 4593 was monitored spectroscopically with the Hubble Space Telescope as part of a reverberation mapping campaign that also included Swift, Kepler, and ground-based photometric monitoring. During 2016 July 12-August 6, we obtained 26 spectra across a nearly continuous wavelength range of ∼1150-10000 Å. These were combined w…
The MOSDEF Survey: A Stellar Mass-SFR-Metallicity Relation Exists at z ∼ 2.3
Barro, Guillermo; Siana, Brian; Shapley, Alice E. +15 more
We investigate the nature of the relation among stellar mass, star formation rate, and gas-phase metallicity (the {M}* -SFR-Z relation) at high redshifts using a sample of 260 star-forming galaxies at z ∼ 2.3 from the MOSDEF survey. We present an analysis of the high-redshift {M}* -SFR-Z relation based on several emission-lin…
Apocenter Pile-up: Origin of the Stellar Halo Density Break
Belokurov, Vasily; Koposov, Sergey E.; Deason, Alis J. +1 more
We measure the orbital properties of halo stars using seven-dimensional information provided by Gaia and the Sloan Digital Sky Survey. A metal-rich population of stars, present in both local main sequence stars and more distant blue horizontal branch stars, have very radial orbits (eccentricity ∼0.9) and apocenters that coincide with the stellar h…
Scaling Relations Associated with Millimeter Continuum Sizes in Protoplanetary Disks
Wilner, David J.; Andrews, Sean M.; Ansdell, Megan +3 more
We present a combined, homogenized analysis of archival Submillimeter Array (SMA) and Atacama Large Millimeter/submillimeter Array (ALMA) observations of the spatially resolved 340 GHz (870 µm) continuum emission from 105 nearby protoplanetary disks. Building on the previous SMA survey, we infer surface brightness profiles using a simple mod…
The Extended Distribution of Baryons around Galaxies
Bregman, Joel N.; Anderson, Michael E.; Qu, Zhijie +5 more
We summarize and reanalyze observations bearing on missing galactic baryons, where we propose a consistent picture for halo gas in L ≳ L* galaxies. The hot X-ray-emitting halos are detected to 50-70 kpc, where typically M hot(<50 kpc) ∼ 5 × 109 M ⊙, and with density n ∝ r -3/2. When extrapolated to R …