Search Publications
PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
Harding, A. K.; Ray, P. S.; Wood, K. S. +18 more
Neutron stars are not only of astrophysical interest, but are also of great interest to nuclear physicists because their attributes can be used to determine the properties of the dense matter in their cores. One of the most informative approaches for determining the equation of state (EoS) of this dense matter is to measure both a star’s equatoria…
An Embedded X-Ray Source Shines through the Aspherical AT 2018cow: Revealing the Inner Workings of the Most Luminous Fast-evolving Optical Transients
Berger, E.; Hurley, K.; Götz, D. +42 more
We present the first extensive radio to γ-ray observations of a fast-rising blue optical transient, AT 2018cow, over its first ∼100 days. AT 2018cow rose over a few days to a peak luminosity L pk ∼ 4 × 1044 erg s-1, exceeding that of superluminous supernovae (SNe), before declining as L ∝ t -2. Initial s…
1ES 1927+654: An AGN Caught Changing Look on a Timescale of Months
Filippenko, Alexei V.; Remillard, Ronald A.; Rest, Armin +21 more
We study the sudden optical and ultraviolet (UV) brightening of 1ES 1927+654, which until now was known as a narrow-line active galactic nucleus (AGN). 1ES 1927+654 was part of the small and peculiar class of “true Type-2” AGNs that lack broad emission lines and line-of-sight obscuration. Our high-cadence spectroscopic monitoring captures the appe…
Constraining the Neutron Star Mass-Radius Relation and Dense Matter Equation of State with NICER. I. The Millisecond Pulsar X-Ray Data Set
Steiner, James F.; Remillard, Ronald A.; Enoto, Teruaki +27 more
We present the set of deep Neutron Star Interior Composition Explorer (NICER) X-ray timing observations of the nearby rotation-powered millisecond pulsars PSRs J0437-4715, J0030+0451, J1231-1411, and J2124-3358, selected as targets for constraining the mass-radius relation of neutron stars and the dense matter equation of state (EoS) via modeling …
Improved Dynamical Constraints on the Masses of the Central Black Holes in Nearby Low-mass Early-type Galactic Nuclei and the First Black Hole Determination for NGC 205
Pechetti, Renuka; Neumayer, Nadine; Strader, Jay +17 more
We improve the dynamical black hole (BH) mass estimates in three nearby low-mass early-type galaxies: NGC 205, NGC 5102, and NGC 5206. We use new Hubble Space Telescope (HST)/STIS spectroscopy to fit the star formation histories of the nuclei in these galaxies, and use these measurements to create local color-mass-to-light ratio (M/L) relations. W…
Short GRB 160821B: A Reverse Shock, a Refreshed Shock, and a Well-sampled Kilonova
Pian, E.; Greiner, J.; Fruchter, A. S. +31 more
We report our identification of the optical afterglow and host galaxy of the short-duration gamma-ray burst sGRB 160821B. The spectroscopic redshift of the host is z = 0.162, making it one of the lowest redshift short-duration gamma-ray bursts (sGRBs) identified by Swift. Our intensive follow-up campaign using a range of ground-based facilities as…
X-Ray Properties of SPT-selected Galaxy Clusters at 0.2 < z < 1.5 Observed with XMM-Newton
Miller, Eric D.; Schrabback, Tim; Holzapfel, W. L. +22 more
We present measurements of the X-ray observables of the intracluster medium (ICM), including luminosity L X , ICM mass M ICM, emission-weighted mean temperature T X , and integrated pressure Y X , that are derived from XMM-Newton X-ray observations of a Sunyaev-Zel’dovich effect (SZE) selected sample …
The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes: New Insights from Faded Changing-look Quasars
Green, Paul J.; Anderson, Scott F.; Eracleous, Michael +5 more
Despite their factor of ∼108 difference in black hole mass, several lines of evidence suggest possible similarities between black hole accretion flows in active galactic nuclei (AGN) and Galactic X-ray binaries. However, it is still unclear whether the geometry of the disk-corona system in X-ray binaries directly scales up to AGN and wh…
A New Class of Changing-look LINERs
Cenko, S. Bradley; Duev, Dmitry A.; Rusholme, Ben +28 more
We report the discovery of six active galactic nuclei (AGNs) caught “turning on” during the first nine months of the Zwicky Transient Facility (ZTF) survey. The host galaxies were classified as low-ionization nuclear emission-line region galaxies (LINERs) by weak narrow forbidden line emission in their archival SDSS spectra, and detected by ZTF as…
The First Tidal Disruption Flare in ZTF: From Photometric Selection to Multi-wavelength Characterization
Cenko, S. Bradley; Riddle, Reed; Rusholme, Ben +37 more
We present Zwicky Transient Facility (ZTF) observations of the tidal disruption flare AT2018zr/PS18kh reported by Holoien et al. and detected during ZTF commissioning. The ZTF light curve of the tidal disruption event (TDE) samples the rise-to-peak exceptionally well, with 50 days of g- and r-band detections before the time of maximum light. We al…