Search Publications
INTEGRAL Discovery of a Burst with Associated Radio Emission from the Magnetar SGR 1935+2154
Tiengo, A.; Sunyaev, R.; Götz, D. +23 more
We report on International Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the soft γ-ray repeater SGR 1935+2154 performed between 2020 April 28 and May 3. Several short bursts with fluence of $\sim {10}^{-7}\mbox{--}{10}^{-6}$ erg cm-2 were detected by the Imager on-board INTEGRAL (IBIS) instrument in the 20-200 keV range.…
Rapid Reionization by the Oligarchs: The Case for Massive, UV-bright, Star-forming Galaxies with High Escape Fractions
Conroy, Charlie; Tacchella, Sandro; Naidu, Rohan P. +3 more
The protagonists of the last great phase transition of the universe - cosmic reionization - remain elusive. Faint star-forming galaxies are leading candidates because they are found to be numerous and may have significant ionizing photon escape fractions (fesc). Here we update this picture via an empirical model that successfully predic…
On the Spectral Evolution of Hot White Dwarf Stars. I. A Detailed Model Atmosphere Analysis of Hot White Dwarfs from SDSS DR12
Fontaine, G.; Bergeron, P.; Bédard, A. +1 more
As they evolve, white dwarfs undergo major changes in surface composition, a phenomenon known as spectral evolution. In particular, some stars enter the cooling sequence with helium atmospheres (type DO) but eventually develop hydrogen atmospheres (type DA), most likely through the upward diffusion of residual hydrogen. Our empirical knowledge of …
The Fourth Fermi-GBM Gamma-Ray Burst Catalog: A Decade of Data
Meegan, C. A.; von Kienlin, A.; Kocevski, D. +18 more
We present the fourth in a series of catalogs of gamma-ray bursts (GRBs) observed with Fermi's Gamma-ray Burst Monitor (Fermi-GBM). It extends the six year catalog by four more years, now covering the 10 year time period from trigger enabling on 2008 July 12 to 2018 July 11. During this time period GBM triggered almost twice a day on transient eve…
The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. II. A Statistical Characterization of Class 0 and Class I Protostellar Disks
Kounkel, Marina; Kratter, Kaitlin; Dunham, Michael M. +33 more
We have conducted a survey of 328 protostars in the Orion molecular clouds with the Atacama Large Millimeter/submillimeter Array at 0.87 mm at a resolution of ∼0"1 (40 au), including observations with the Very Large Array at 9 mm toward 148 protostars at a resolution of ∼0"08 (32 au). This is the largest multiwavelength survey of protostars at thi…
Gamma-Ray Burst Afterglows in the Multimessenger Era: Numerical Models and Closure Relations
Piro, Luigi; Ryan, Geoffrey; Troja, Eleonora +1 more
Gamma-ray bursts (GRBs) associated with gravitational wave events are, and will likely continue to be, viewed at a larger inclination than GRBs without gravitational wave detections. As demonstrated by the afterglow of GW 170817A, this requires an extension of the common GRB afterglow models, which typically assume emission from an on-axis top-hat…
Host Galaxy Properties and Offset Distributions of Fast Radio Bursts: Implications for Their Progenitors
Kilpatrick, Charles D.; Simha, Sunil; Mannings, Alexandra +15 more
We present observations and detailed characterizations of five new host galaxies of fast radio bursts (FRBs) discovered with the Australian Square Kilometre Array Pathfinder (ASKAP) and localized to ≲1″. Combining these galaxies with FRB hosts from the literature, we introduce criteria based on the probability of chance coincidence to define a sub…
Hubble Space Telescope Observations of Mira Variables in the SN Ia Host NGC 1559: An Alternative Candle to Measure the Hubble Constant
Casertano, Stefano; Filippenko, Alexei V.; Riess, Adam G. +7 more
We present year-long, near-infrared Hubble Space Telescope (HST) WFC3 observations used to search for Mira variables in NGC 1559, the host galaxy of the Type Ia supernova (SN Ia) SN 2005df. This is the first dedicated search for Miras, highly evolved low-mass stars, in an SN Ia host, and subsequently the first calibration of the SN Ia luminosity u…
Discovery of a 2.8 s Pulsar in a 2 Day Orbit High-mass X-Ray Binary Powering the Ultraluminous X-Ray Source ULX-7 in M51
Salvaterra, R.; Haberl, F.; Tiengo, A. +26 more
We discovered 2.8 s pulsations in the X-ray emission of the ultraluminous X-ray source (ULX) M51 ULX-7 within the UNSEeN project, which was designed to hunt for new pulsating ULXs (PULXs) with XMM-Newton. The pulse shape is sinusoidal, and large variations of its amplitude were observed even within single exposures (pulsed fraction from less than …
How Well Can We Measure the Stellar Mass of a Galaxy: The Impact of the Assumed Star Formation History Model in SED Fitting
Conroy, Charlie; Johnson, Benjamin D.; Davé, Romeel +3 more
The primary method for inferring the stellar mass (M*) of a galaxy is through spectral energy distribution (SED) modeling. However, the technique rests on assumptions such as the galaxy star formation history (SFH) and dust attenuation law that can severely impact the accuracy of derived physical properties from SED modeling. Here we ex…