Search Publications
Comparison of Observed Galaxy Properties with Semianalytic Model Predictions Using Machine Learning
Mobasher, Bahram; Chartab, Nima; Lu, Yu +1 more
With current and upcoming experiments such as the Wide Field Infrared Survey Telescope, Euclid, and Large Synoptic Survey Telescope, we can observe up to billions of galaxies. While such surveys cannot obtain spectra for all observed galaxies, they produce galaxy magnitudes in color filters. This data set behaves like a high-dimensional nonlinear …
Emergence of Internetwork Magnetic Fields through the Solar Atmosphere
Gošić, M.; De Pontieu, B.; Bellot Rubio, L. R. +2 more
Internetwork (IN) magnetic fields are highly dynamic, short-lived magnetic structures that populate the interior of supergranular cells. Since they emerge all over the Sun, these small-scale fields bring a substantial amount of flux, and therefore energy, to the solar surface. Because of this, IN fields are crucial for understanding the quiet Sun …
The Effects of Biconical Outflows on Lyα Escape from Green Peas
Scarlata, Claudia; Henry, Alaina; Carr, Cody +1 more
We analyze the spectra of 10 Green Pea galaxies, previously studied by Henry et al., using a semi-analytical line transfer model to interpret emission and absorption features observed in UV galactic spectra. We focus our analysis on various ionization states of silicon, associated with the cool (∼104 K) and warm (∼105 K) gas.…
Galaxy Properties at the Faint End of the H I Mass Function
McQuinn, Kristen B. W.; Cannon, John M.; Dolphin, Andrew E. +9 more
The Survey of H I in Extremely Low-mass Dwarfs (SHIELD) includes a volumetrically complete sample of 82 gas-rich dwarfs with ${M}_{{\rm{H}}\,{\rm\small{I}}}\lesssim {10}^{7.2}$ ${M}_{\odot }$ selected from the ALFALFA survey. We are obtaining extensive follow-up observations of the SHIELD galaxies to study their gas, stellar, and chemical content,…
The Blue Supergiant Progenitor of the Supernova Imposter AT 2019krl
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Kochanek, C. S. +20 more
Extensive archival Hubble Space Telescope, Spitzer Space Telescope, and Large Binocular Telescope imaging of the recent intermediate-luminosity transient, AT 2019krl in M74, reveal a bright optical and mid-infrared progenitor star. While the optical peak of the event was missed, a peak was detected in the infrared with an absolute magnitude of M
Far-ultraviolet Spectra of Main-sequence O Stars at Extremely Low Metallicity
McQuinn, Kristen B. W.; Chisholm, John; Berg, Danielle A. +1 more
Metal-poor massive stars dominate the light we observe from star-forming dwarf galaxies and may have produced the bulk of energetic photons that reionized the universe at high redshift. Yet, the rarity of observations of individual O stars below the 20% solar metallicity (Z ⊙) of the Small Magellanic Cloud (SMC) hampers our ability to m…
"Worst-case" Microlensing in the Identification and Modeling of Lensed Quasars
Schechter, Paul L.; Weisenbach, Luke; Pontula, Sahil
Although microlensing of macrolensed quasars and supernovae provides unique opportunities for several kinds of investigations, it can add unwanted and sometimes substantial noise. While microlensing flux anomalies may be safely ignored for some observations, they severely limit others. "Worst-case" estimates can inform the decision whether or not …
Modeling a Coronal Mass Ejection from an Extended Filament Channel. I. Eruption and Early Evolution
Kazachenko, Maria D.; Lynch, Benjamin J.; Palmerio, Erika +4 more
We present observations and modeling of the magnetic field configuration, morphology, and dynamics of a large-scale, high-latitude filament eruption observed by the Solar Dynamics Observatory. We analyze the 2015 July 9-10 filament eruption and the evolution of the resulting coronal mass ejection (CME) through the solar corona. The slow streamer-b…
Massive Star Cluster Formation and Destruction in Luminous Infrared Galaxies in GOALS. II. An ACS/WFC3 Survey of Nearby LIRGs
Surace, J. A.; Inami, H.; Murphy, E. J. +14 more
We present the results of a Hubble Space Telescope WFC3 near-UV and Advanced Camera for Surveys Wide Field Channel optical study into the star cluster populations of a sample of 10 luminous infrared galaxies (LIRGs) in the Great Observatories All-Sky LIRG Survey. Through integrated broadband photometry we have derived ages, masses, and extinctions…
The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. IV. The Star Formation History of Andromeda VII Derived from Long-period Variable Stars
Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +10 more
We have examined the star formation history (SFH) of Andromeda VII (And VII), the brightest and most massive dwarf spheroidal (dSph) satellite of the Andromeda galaxy (M31). Although M31 is surrounded by several dSph companions with old stellar populations and low metallicity, it has a metal-rich stellar halo with an age of 6-8 Gyr. This indicates…