Search Publications
A Precision Measurement of the Mass of the Black Hole in NGC 3258 from High-resolution ALMA Observations of Its Circumnuclear Disk
Ho, Luis C.; Barth, Aaron J.; Buote, David A. +4 more
We present ∼0.″10 resolution Atacama Large Millimeter/submillimeter Array (ALMA) CO(2-1) imaging of the arcsecond-scale (r ≈ 150 pc) dusty molecular disk in the giant elliptical galaxy NGC 3258. The data provide unprecedented resolution of the cold gas disk kinematics within the dynamical sphere of influence of a supermassive black hole (BH), reve…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVIII. Proper-motion Kinematics of Multiple Stellar Populations in the Core Regions of NGC 6352
Vesperini, Enrico; Anderson, Jay; van der Marel, Roeland P. +5 more
We present the analysis of the radial distributions and kinematic properties of the multiple stellar populations (mPOPs) hosted in the globular cluster (GC) NGC 6352 as part of the Hubble Space Telescope “UV Legacy Survey of Galactic Globular Clusters” program. NGC 6352 is one of the few GCs for which the mPOP tagging in appropriate color-magnitud…
The Mass Inflow and Outflow Rates of the Milky Way
Richter, Philipp; Heckman, Timothy M.; Fox, Andrew J. +5 more
We present new calculations of the mass inflow and outflow rates around the Milky Way (MW), derived from a catalog of ultraviolet metal-line high-velocity clouds (HVCs). These calculations are conducted by transforming the HVC velocities into the Galactic standard of rest (GSR) reference frame, identifying inflowing (v GSR < 0 km s
Orbital Decay in a 20 Minute Orbital Period Detached Binary with a Hydrogen-poor Low-mass White Dwarf
Kulkarni, S. R.; Duev, Dmitry A.; Riddle, Reed +14 more
We report the discovery of a detached double white dwarf binary with an orbital period of ≈20.6 minutes, PTF J053332.05+020911.6. The visible object in this binary, PTF J0533+0209B, is a ≈0.17 M ⊙ mass white dwarf with a helium-dominated atmosphere containing traces of hydrogen. This object exhibits ellipsoidal variations due to tidal d…
Resolving CO (2-1) in z ∼ 1.6 Gas-rich Cluster Galaxies with ALMA: Rotating Molecular Gas Disks with Possible Signatures of Gas Stripping
Cooper, M. C.; van Kampen, E.; Demarco, R. +10 more
We present the first spatially resolved observations of molecular gas in a sample of cluster galaxies beyond z > 0.1. Using ALMA, we detect CO (2-1) in eight z ∼ 1.6 cluster galaxies, all within a single 70″ primary beam. The cluster, SpARCS-J0225, was discovered by the Spitzer Adaptation of the Red-sequence Cluster Survey, and is replete with …
Hubble Space Telescope Nondetection of PSR J2144-3933: The Coldest Known Neutron Star
Pavlov, George G.; Kargaltsev, Oleg; Guillot, Sebastien +4 more
We report nondetections of the ∼3 × 108 yr old, slow, isolated, rotation-powered pulsar PSR J2144-3933 in observations with the Hubble Space Telescope in one optical band (F475X) and two far-ultraviolet bands (F125LP and F140LP), yielding upper bounds {F}{{F}475{{X}}}< 22.7 {nJy}, {F}{{F}125{LP}}< 5.9 {nJy}, …
Butterfly in a Cocoon, Understanding the Origin and Morphology of Globular Cluster Streams: The Case of GD-1
Malhan, Khyati; Ibata, Rodrigo A.; Carlberg, Raymond G. +2 more
Tidally disrupted globular cluster (GC) streams are usually observed, and therefore perceived, as narrow, linear, and one-dimensional structures in the 6D phase space. Here, we show that the GD-1 stellar stream, which is the tidal debris of a disrupted GC, possesses a secondary diffuse and extended stellar component (∼100 pc wide) around it, detec…
ACR Proton Acceleration Associated with Reconnection Processes beyond the Heliospheric Termination Shock
Chen, Y.; Burlaga, L. F.; Zank, G. P. +6 more
One of the curious observations from the Voyagers is that the intensity of anomalous cosmic rays (ACRs) did not peak at the heliospheric termination shock (HTS) but instead a short distance (within ∼1 au) downstream of the HTS. One possible explanation is that the interaction of the wavy heliospheric current sheet with the HTS enhances magnetic re…
Heliospheric Evolution of Magnetic Clouds
Möstl, C.; Farrugia, C. J.; Temmer, M. +7 more
The interplanetary evolution of 11 magnetic clouds (MCs) recorded by at least two radially aligned spacecraft is studied. The in situ magnetic field measurements are fitted to a cylindrically symmetric Gold-Hoyle force-free uniform-twist flux-rope configuration. The analysis reveals that in a statistical sense, the expansion of the studied MCs is …
The Sloan Digital Sky Survey Reverberation Mapping Project: Accretion and Broad Emission Line Physics from a Hypervariable Quasar
Trump, Jonathan R.; Green, Paul J.; Brandt, W. N. +18 more
We analyze extensive spectroscopic and photometric data of the hypervariable quasar SDSS J141324+530527 (RMID 017) at z = 0.456, an optical “changing-look” quasar from the Sloan Digital Sky Survey Reverberation Mapping project that increased in optical luminosity by a factor ≃10 between 2014 and 2017. The observed broad emission lines all respond …