Search Publications
LensFlow: A Convolutional Neural Network in Search of Strong Gravitational Lenses
Cooray, Asantha; Nayyeri, Hooshang; Pourrahmani, Milad
In this work, we present our machine learning classification algorithm for identifying strong gravitational lenses from wide-area surveys using convolutional neural networks; LENSFLOW. We train and test the algorithm using a wide variety of strong gravitational lens configurations from simulations of lensing events. Images are processed through mu…
Detection of Reflection Features in the Neutron Star Low-mass X-Ray Binary Serpens X-1 with NICER
Fabian, A. C.; Miller, J. M.; Homan, J. +17 more
We present Neutron Star Interior Composition Explorer (NICER) observations of the neutron star (NS) low-mass X-ray binary Serpens X-1 during the early mission phase in 2017. With the high spectral sensitivity and low-energy X-ray passband of NICER, we are able to detect the Fe L line complex in addition to the signature broad, asymmetric Fe K line…
Results from a Systematic Survey of X-Ray Emission from Hydrogen-poor Superluminous SNe
Berger, E.; Chornock, R.; Lunnan, R. +11 more
We present the results from a sensitive X-ray survey of 26 nearby hydrogen-poor superluminous supernovae (SLSNe-I) with Swift, Chandra, and XMM. This data set constrains the SLSN evolution from a few days until ∼2000 days after explosion, reaching a luminosity limit L x ∼ 1040 erg s-1 and revealing the presence o…
RELICS: Strong Lens Models for Five Galaxy Clusters from the Reionization Lensing Cluster Survey
Frye, Brenda L.; Bradač, Maruša; Lovisari, Lorenzo +31 more
Strong gravitational lensing by galaxy clusters magnifies background galaxies, enhancing our ability to discover statistically significant samples of galaxies at {\boldsymbol{z}}> 6, in order to constrain the high-redshift galaxy luminosity functions. Here, we present the first five lens models out of the Reionization Lensing Cluster Survey (RE…
Identifying Typical Mg II Flare Spectra Using Machine Learning
Krucker, Säm; Kleint, Lucia; Panos, Brandon +4 more
The Interface Region Imaging Spectrograph (IRIS) performs solar observations over a large range of atmospheric heights, including the chromosphere where the majority of flare energy is dissipated. The strong Mg II h&k spectral lines are capable of providing excellent atmospheric diagnostics, but have not been fully utilized for flaring atmosph…
A Large and Pristine Sample of Standard Candles across the Milky Way: ∼100,000 Red Clump Stars with 3% Contamination
Ting, Yuan-Sen; Rix, Hans-Walter; Hawkins, Keith
Core helium-burning red clump (RC) stars are excellent standard candles in the Milky Way. These stars may have more precise distance estimates from spectrophotometry than from Gaia parallaxes beyond 3 kpc. However, RC stars have values of T eff and {log}g that are very similar to some red giant branch (RGB) stars. Especially for low-res…
Reconciling Observed and Simulated Stellar Halo Masses
Faucher-Giguère, Claude-André; Hopkins, Philip F.; Wetzel, Andrew +6 more
We use cosmological hydrodynamical simulations of Milky Way-mass galaxies from the FIRE project to evaluate various strategies for estimating the mass of a galaxy’s stellar halo from deep, integrated-light images. We find good agreement with integrated-light observations if we mimic observational methods to measure the mass of the stellar halo by …
Characterizing Accreting Double White Dwarf Binaries with the Laser Interferometer Space Antenna and Gaia
Larson, Shane L.; Breivik, Katelyn; Kremer, Kyle +3 more
We demonstrate a method to fully characterize mass-transferring double white dwarf (DWD) systems with a helium-rich (He) white dwarf (WD) donor based on the mass-radius (M-R) relationship for He WDs. Using a simulated Galactic population of DWDs, we show that donor and accretor masses can be inferred for up to ∼60 systems observed by both Laser In…
Gaia 17bpi: An FU Ori-type Outburst
Naylor, Tim; Mainzer, Amy K.; Hillenbrand, Lynne A. +7 more
We report on the source Gaia 17bpi and identify it as a new, ongoing FU Ori-type outburst, associated with a young stellar object. The optical light curve from Gaia exhibited a 3.5 mag rise with the source appearing to plateau in mid-/late 2018. Mid-infrared observations from NEOWISE also show a >3 mag rise that occurred in two stages, with the…
Larger Mutual Inclinations for the Shortest-period Planets
Winn, Joshua N.; Dai, Fei; Masuda, Kento
The Kepler mission revealed a population of compact multiple-planet systems with orbital periods shorter than a year, and occasionally even shorter than a day. By analyzing a sample of 102 Kepler and K2 multiple-planet systems, we measure the minimum difference ΔI between the orbital inclinations, as a function of the orbital distance of the inner…