Search Publications
High-latitude Observations of Inertial-range Turbulence by the Ulysses Spacecraft During the Solar Minimum of 1993-96
Isenberg, Philip A.; Schwadron, Nathan A.; Murphy, Neil +8 more
We have examined Ulysses magnetic field measurements for the years 1993 through 1996 as the spacecraft moved sunward from 5 au at high southern latitudes, passing through perihelion during the first fast-latitude scan to achieve high northern latitudes, and finally returning to 5 au. These years represent near-solar-minimum activity, providing a c…
Distances to Local Group Galaxies via Population II, Stellar Distance Indicators. II. The Fornax Dwarf Spheroidal
Madore, Barry F.; Freedman, Wendy L.; Cerny, William +5 more
We determine three independent Population II distance moduli to the Fornax dwarf spheroidal (dSph) galaxy, using wide-field, ground-based VI imaging acquired with the Magellan-Baade telescope at Las Campanas Observatory. After subtracting foreground stars using Gaia EDR3 proper motions, we measure an I-band tip of the red giant branch (TRGB) magni…
On the Characterization of GJ 504: A Magnetically Active Planet-host Star Observed by the Transiting Exoplanet Survey Satellite (TESS)
Stassun, Keivan G.; García, Rafael A.; Corsaro, Enrico +11 more
We present the results of the analysis of the photometric data collected in long- and short-cadence mode by the Transiting Exoplanet Survey Satellite for GJ 504, a well-studied planet-hosting solar-like star, whose fundamental parameters have been largely debated during the last decade. Several attempts have been made by the present authors to iso…
Using Multiple Emission Line Ratios to Constrain the Slope of the Dust Attenuation Law
Papovich, Casey; Cleri, Nikko J.; Trump, Jonathan R. +2 more
We explore the possibility and practical limitations of using a three-line approach to measure both the slope and normalization of the dust attenuation law in individual galaxies. To do this, we focus on a sample of 11 galaxies with existing ground-based Balmer Hα and Hβ measurements from slit spectra, plus space-based grism constraints on Paschen…
The Missing Metal Problem in Galaxy Clusters: Characterizing the Early Enrichment Population
Bregman, Joel N.; Blackwell, Anne E.; Snowden, Steven L.
Rich and poor galaxy clusters have the same measured halo metallicity, 0.35-0.4 Z ⊙, even though they are an order of magnitude apart in stellar fraction, M */M gas. The measured intracluster medium (ICM) metallicity in high-mass clusters cannot be explained by the visible stellar population as stars typically make…
On the Nature of Rotation in the Praesepe Cluster
Hao, C. J.; Xu, Y.; Hou, L. G. +4 more
Although a large number of Galactic open clusters (OCs) have been identified, the internal kinematic properties (e.g., rotation) of almost all the known OCs are still far from clear. With the high-precision astrometric data of Gaia EDR3, we have developed a methodology to unveil the rotational properties of the Praesepe cluster. Statistics of the …
A Radio-selected Population of Dark, Long Gamma-Ray Bursts: Comparison to the Long Gamma-Ray Burst Population and Implications for Host Dust Distributions
Kilpatrick, Charles D.; Andrews, Jennifer; Miller, Adam A. +17 more
We present centimeter-band and millimeter-band afterglow observations of five long-duration γ-ray bursts (GRBs; GRB 130131A, 130420B, 130609A, 131229A, 140713A) with dust-obscured optical afterglow emission, known as "dark" GRBs. We detect the radio afterglow of two of the dark GRBs (GRB 130131A and 140713A), along with a tentative detection of a …
X-Ray Observations of the Isolated Black Hole Candidate OGLE-2011-BLG-0462 and Other Collapsed Objects Discovered through Gravitational Microlensing
Mereghetti, S.; Ponti, G.; Sidoli, L. +1 more
Isolated black holes and neutron stars can be revealed through the observation of long-duration gravitational microlensing events. A few candidates have been found in surveys of stars in the direction of the Galactic bulge. Recently, thanks to the addition of astrometric information at milliarcsecond level, it has been possible to reduce the uncer…
Spectral Evolution of Ultraluminous X-Ray Pulsar NGC 300 ULX-1
Steiner, James F.; Remillard, Ronald A.; Chakrabarty, Deepto +2 more
We report on results from a 1 yr soft X-ray observing campaign of the ultraluminous X-ray pulsar NGC 300 ULX-1 by the Neutron star Interior Composition Explorer (NICER) during 2018-2019. Our analysis also made use of data from Swift/XRT and XMM-Newton in order to model and remove contamination from the nearby eclipsing X-ray binary NGC 300 X-1. We…
Improving Planet Detection with Disk Modeling: Keck/NIRC2 Imaging of the HD 34282 Single-armed Protoplanetary Disk
Dong, Ruobing; Millar-Blanchaer, Maxwell A.; Wallack, Nicole L. +5 more
Formed in protoplanetary disks around young stars, giant planets can leave observational features such as spirals and gaps in their natal disks through planet-disk interactions. Although such features can indicate the existence of giant planets, protoplanetary disk signals can overwhelm the innate luminosity of planets. Therefore, in order to imag…