Search Publications
Early Results from GLASS-JWST. XXI. Rapid Asembly of a Galaxy at z = 6.23 Revealed by Its C/O Abundance
Santini, Paola; Pentericci, Laura; Treu, Tommaso +22 more
The abundance of carbon relative to oxygen (C/O) is a promising probe of star formation history in the early universe, as the ratio changes with time due to production of these elements by different nucleosynthesis pathways. We present a measurement of $\mathrm{log}({\rm{C}}/{\rm{O}})=-1.01\pm 0.12$ (stat) ±0.15 (sys) in a z = 6.23 galaxy observed…
From Images to Dark Matter: End-to-end Inference of Substructure from Hundreds of Strong Gravitational Lenses
Marshall, Philip J.; Birrer, Simon; Darragh-Ford, Elise +4 more
Constraining the distribution of small-scale structure in our universe allows us to probe alternatives to the cold dark matter paradigm. Strong gravitational lensing offers a unique window into small dark matter halos (<1010 M ⊙) because these halos impart a gravitational lensing signal even if they do not host luminous ga…
Optimized Photometric Redshifts for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS)
Finkelstein, Steven L.; Pérez-González, Pablo G.; Santini, Paola +27 more
We present the first comprehensive release of photometric redshifts (photo- z's) from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) team. We use statistics based upon the Quantile-Quantile (Q-Q) plot to identify biases and signatures of underestimated or overestimated errors in photo- z probability density functions …
Pegasus IV: Discovery and Spectroscopic Confirmation of an Ultra-faint Dwarf Galaxy in the Constellation Pegasus
Zenteno, A.; James, D. J.; Li, T. S. +31 more
We report the discovery of Pegasus IV, an ultra-faint dwarf galaxy found in archival data from the Dark Energy Camera processed by the DECam Local Volume Exploration Survey. Pegasus IV is a compact, ultra-faint stellar system ( ${r}_{1/2}={41}_{-6}^{+8}$ pc; M V = -4.25 ± 0.2 mag) located at a heliocentric distance of ${90}_{-6}^{+4}\…
The Fundamental Signature of Star Formation Quenching from AGN Feedback: A Critical Dependence of Quiescence on Supermassive Black Hole Mass, Not Accretion Rate
Maiolino, Roberto; Bluck, Asa F. L.; Piotrowska, Joanna M.
We identify the intrinsic dependence of star formation quenching on a variety of galactic and environmental parameters, utilizing a machine-learning approach with Random Forest classification. We have previously demonstrated the power of this technique to isolate causality, not mere correlation, in complex astronomical data. First, we analyze thre…
Confirmation of Subsolar Metallicity for WASP-77Ab from JWST Thermal Emission Spectroscopy
Bean, Jacob L.; Zhang, Michael; Line, Michael +4 more
We present the dayside thermal emission spectrum of WASP-77Ab from 2.8 to 5.2 µm as observed with the NIRSpec instrument on the James Webb Space Telescope (JWST). WASP-77Ab was previously found to have a subsolar metallicity and a solar carbon-to-oxygen (C/O) ratio from H2O and CO absorption lines detected using high-resolution sp…
Streams on FIRE: Populations of Detectable Stellar Streams in the Milky Way and FIRE
Lewis, Geraint F.; Erkal, Denis; Bland-Hawthorn, Joss +20 more
We present the first detailed comparison of populations of dwarf galaxy stellar streams in cosmological simulations and the Milky Way. In particular, we compare streams identified around 13 Milky Way analogs in the FIRE-2 simulations to streams observed by the Southern Stellar Stream Spectroscopic Survey (S 5). For an accurate compariso…
Millimeter Observations of the Type II SN 2023ixf: Constraints on the Proximate Circumstellar Medium
Rao, Ramprasad; Eftekhari, Tarraneh; Berger, Edo +10 more
We present 1.3 mm (230 GHz) observations of the recent and nearby Type II supernova, SN 2023ixf, obtained with the Submillimeter Array (SMA) at 2.6-18.6 days after explosion. The observations were obtained as part the SMA Large Program, POETS (Pursuit of Extragalactic Transients with the SMA). We do not detect any emission at the location of SN 20…
The Dusty Red Supergiant Progenitor and the Local Environment of the Type II SN 2023ixf in M101
Niu, Zexi; Sun, Ning-Chen; Liu, Jifeng +3 more
As one of the closest supernovae (SNe) in the last decade, SN 2023ixf is an unprecedented target to investigate the progenitor star that exploded. However, there is still significant uncertainty in the reported progenitor properties. In this work, we present a detailed study of SN 2023ixf's progenitor with two independent analyses. We first modele…
The Young and the Wild: What Happens to Protoclusters Forming at Redshift z ≈ 4?
Dolag, Klaus; Dannerbauer, Helmut; Remus, Rhea-Silvia
Using one of the largest volumes of the hydrodynamical cosmological simulation suit Magneticum, we study the evolution of protoclusters identified at redshift ≈ 4, with properties similar to the well-observed protocluster SPT2349-56. We identify 42 protoclusters in the simulation as massive and equally rich in substructures as observed, confirming…