Search Publications
GOALS-JWST: Unveiling Dusty Compact Sources in the Merging Galaxy IIZw096
Inami, Hanae; Böker, Torsten; Kemper, Francisca +30 more
We have used the Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) to obtain the first spatially resolved, mid-infrared images of IIZw096, a merging luminous infrared galaxy (LIRG) at z = 0.036. Previous observations with the Spitzer Space Telescope suggested that the vast majority of the total IR luminosity (L IR)…
Is There an Enormous Cold Front at the Virial Radius of the Perseus Cluster?
Fabian, A. C.; Sanders, J. S.; Walker, S. A. +3 more
We present new XMM-Newton observations extending the mosaic of the Perseus cluster out to the virial radius to the west. Previous studies with ROSAT have reported a large excess in surface brightness to the west, possibly the result of large-scale gas sloshing. In our new XMM-Newton observations we have found two X-ray surface brightness edges at …
Late-onset Circumstellar Medium Interactions are Rare: An Unbiased GALEX View of Type Ia Supernovae
Shappee, Benjamin J.; Anand, Gagandeep S.; Tucker, Michael A. +2 more
Using ultraviolet (UV) light curves, we constrain the circumstellar environments of 1080 Type Ia supernovae (SNe Ia) within z < 0.5 from archival Galaxy Evolution Explorer (GALEX) observations. All SNe Ia are required to have pre- and post-explosion GALEX observations to ensure adequate subtraction of the host-galaxy flux. Using the late-time G…
Conditions for Direct Black Hole Seed Collapse near a Radio-loud Quasar 1 Gyr after the Big Bang
Overzier, Roderik A.
Observations of luminous quasars and their supermassive black holes at z ≳ 6 suggest that they formed at dense matter peaks in the early universe. However, few studies have found definitive evidence that the quasars lie at cosmic density peaks, in clear contrast with theory predictions. Here we present new evidence that the radio-loud quasar SDSS …
High-frequency Magnetic Fluctuations in Space Plasmas and the Role of Electron Landau Damping
Telloni, Daniele; Vecchio, Antonio; Lepreti, Fabio +1 more
While low-frequency plasma fluctuations in the interplanetary space have been successfully described in the framework of classical turbulence, high-frequency fluctuations still represent a challenge for theoretical models. At these scales, kinetic plasma processes are at work, but although some of them have been identified in spacecraft measuremen…
Multimessenger Constraints on Magnetic Fields in Merging Black Hole-Neutron Star Binaries
Haiman, Zoltán; D'Orazio, Daniel J.; Vigna-Gómez, Alejandro +2 more
The LIGO-Virgo-KAGRA Collaboration recently detected gravitational waves (GWs) from the merger of black hole-neutron star (BHNS) binary systems GW200105 and GW200115. No coincident electromagnetic (EM) counterparts were detected. While the mass ratio and BH spin in both systems were not sufficient to tidally disrupt the NS outside the BH event hor…
Metallicity Distribution Function of the Eridanus II Ultra-faint Dwarf Galaxy from Hubble Space Telescope Narrowband Imaging
Dolphin, Andrew E.; Martin, Nicolas; Starkenburg, Else +9 more
We use deep narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group ultra-faint dwarf galaxy Eridanus II (Eri II). When combined with archival F475W and F814W data, we measure metallicities for 60 resolved red giant branch stars as faint as m F475W
A First Look into the Nature of JWST/MIRI 7.7 µm Sources from SMACS 0723
Rinaldi, Pierluigi; Caputi, Karina I.; Iani, Edoardo +1 more
Until now, our knowledge of the extragalactic universe at mid-infrared (mid-IR) wavelengths (>5 µm) was limited to rare active galactic nuclei and the brightest normal galaxies up to z ~ 3. The advent of JWST with its Mid-Infrared Instrument (MIRI) will revolutionize the ability of the mid-IR regime as a key wavelength domain to probe the…
Microlensing Events in the Galactic Plane Using the Zwicky Transient Facility
Duev, Dmitry A.; Riddle, Reed; Mróz, Przemek +10 more
Microlensing is a powerful technique to study the Galactic population of "dark" objects such as exoplanets both bound and unbound, brown dwarfs, low-luminosity stars, old white dwarfs, and neutron stars, and it is almost the only way to study isolated stellar-mass black holes. The majority of previous efforts to search for gravitational microlensi…
A Temperature Trend for Clouds and Hazes in Exoplanet Atmospheres
Swain, Mark R.; Estrela, Raissa; Roudier, Gael M.
The transmission spectra of exoplanet atmospheres observed with the Hubble Space Telescope (HST) in the near-infrared range (1.1-1.65 µm) frequently show evidence for some combination of clouds and hazes. Identification of systematic trends in exoplanet clouds and hazes is potentially important for understanding atmospheric composition and t…