Search Publications
Evolution of Galaxy Star Formation and Metallicity: Impact on Double Compact Object Mergers
Danese, L.; Lapi, A.; Donevski, D. +3 more
In this paper, we study the impact of different galaxy statistics and empirical metallicity scaling relations on the merging rates and properties of compact object binaries. Firstly, we analyze the similarities and differences of using the star formation rate functions versus stellar mass functions as galaxy statistics for the computation of cosmi…
The Evolving Interstellar Medium of Star-forming Galaxies, as Traced by Stardust
Brammer, Gabriel; Daddi, Emanuele; Toft, Sune +13 more
We analyze the far-infrared (FIR) properties of ~5000 star-forming galaxies at z < 4.5, drawn from the deepest, super-deblended catalogs in the GOODS-N and COSMOS fields. We develop a novel panchromatic spectral energy distribution fitting algorithm, Stardust, that models the emission from stars, active galactic nuclei (AGNs), and infrared dust…
New Candidate Extreme T Subdwarfs from the Backyard Worlds: Planet 9 Citizen Science Project
Debes, John H.; Meisner, Aaron M.; Line, Michael R. +27 more
Schneider et al. presented the discovery of WISEA J041451.67-585456.7 and WISEA J181006.18-101000.5, which appear to be the first examples of extreme T-type subdwarfs (esdTs; metallicity ≤-1 dex, Teff ≲ 1400 K). Here, we present new discoveries and follow-up of three T-type subdwarf candidates, with an eye toward expanding the sample of…
A Catalog of 204 Offset and Dual Active Galactic Nuclei (AGNs): Increased AGN Activation in Major Mergers and Separations under 4 kpc
Griffith, Roger L.; Stern, Daniel; Stemo, Aaron +4 more
During galaxy mergers, gas and dust are driven toward the centers of merging galaxies, triggering enhanced star formation and supermassive black hole (SMBH) growth. Theory predicts that this heightened activity peaks at SMBH separations <20 kpc; if sufficient material accretes onto one or both of the SMBHs for them to become observable as activ…
The Photometric Metallicity and Carbon Distributions of the Milky Way's Halo and Solar Neighborhood from S-PLUS Observations of SDSS Stripe 82
Yoon, Jinmi; Whitten, Devin D.; Beers, Timothy C. +14 more
We report photometric estimates of effective temperature, Teff, metallicity, [Fe/H], carbonicity, [C/Fe], and absolute carbon abundances, A(C), for over 700,000 stars from the Southern Photometric Local Universe Survey (S-PLUS) Data Release 2, covering a substantial fraction of the equatorial Sloan Digital Sky Survey Stripe 82. We prese…
Photochemistry and Spectral Characterization of Temperate and Gas-rich Exoplanets
Hu, Renyu
Exoplanets that receive stellar irradiance approximately equal to Earth's or less have been discovered and many are suitable for spectral characterization. Here, we focus on the temperate planets that have massive H2-dominated atmospheres, and trace the chemical reactions and transport following the photodissociation of H2O, …
Discovery of an Ultra-faint Stellar System near the Magellanic Clouds with the DECam Local Volume Exploration Survey
James, D. J.; Kuropatkin, N.; Li, T. S. +30 more
We report the discovery of a new ultra-faint stellar system found near the Magellanic Clouds in the DECam Local Volume Exploration Survey. This new system, DELVE J0155-6815 (DELVE 2), is located at a heliocentric distance of D⊙ = 71 ± 4 kpc, which places it at a 3D physical separation of 12 ± 3 kpc from the center of the Small Magellani…
CO Excitation, Molecular Gas Density, and Interstellar Radiation Field in Local and High-redshift Galaxies
Daddi, Emanuele; Schinnerer, Eva; Liu, Daizhong +9 more
We study the carbon monoxide (CO) excitation, mean molecular gas density, and interstellar radiation field (ISRF) intensity in a comprehensive sample of 76 galaxies from local to high redshift (z ∼ 0-6), selected based on detections of their CO transitions J = 2 → 1 and 5 → 4 and their optical/infrared/(sub)millimeter spectral energy distributions…
The First Dynamical Mass Measurement in the HR 8799 System
Dupuy, Trent J.; Brandt, Timothy D.; Brandt, G. Mirek +2 more
HR 8799 hosts four directly imaged giant planets, but none has a mass measured from first principles. We present the first dynamical mass measurement in this planetary system, finding that the innermost planet HR 8799 e has a mass of ${9.6}_{-1.8}^{+1.9}\,{M}_{\mathrm{Jup}}$ . This mass results from combining the well-characterized orbits of all f…
Evolution of Switchbacks in the Inner Heliosphere
Velli, Marco; Matteini, Lorenzo; Sioulas, Nikos +3 more
We analyze magnetic field data from the first six encounters of Parker Solar Probe, three Helios fast streams and two Ulysses south polar passes covering heliocentric distances 0.1 ≲ R ≲ 3 au. We use this data set to statistically determine the evolution of switchbacks of different periods and amplitudes with distance from the Sun. We compare the …