Search Publications
Dynamics of a Galaxy at z > 10 Explored by JWST Integral Field Spectroscopy: Hints of Rotating Disk Suggesting Weak Feedback
Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +9 more
We investigate the dynamics of GN-z11, a luminous galaxy at z = 10.60, carefully analyzing the public deep integral field spectroscopy (IFS) data taken with the JWST NIRSpec integral field unit. While the observations of the IFS data originally targeted an He II clump near GN-z11, we find that the C III] λ λ1907, 1909 emission from ionized gas at …
Precision MARS Mass Reconstruction of A2744: Synergizing the Largest Strong-lensing and Densest Weak-lensing Data Sets from JWST
Jee, M. James; Cha, Sangjun; HyeongHan, Kim +2 more
We present a new high-resolution free-form mass model of A2744 that combines both weak-lensing (WL) and strong-lensing (SL) data sets from JWST. The SL data set comprises 286 multiple images, presenting the most extensive SL constraint to date for a single cluster. The WL data set, employing photo-z selection, yields a source density of $\sim 350\…
Dead or Alive? How Bursty Star Formation and Patchy Dust Can Cause Temporary Quiescence in High-redshift Galaxies
Morishita, Takahiro; Faisst, Andreas L.
The recent discovery of a galaxy at z = 7.3 with undetected optical emission lines and a blue UV-to-optical continuum ratio in JWST spectroscopy is surprising and needs to be explained physically. Here, we explore two possibilities that could cause such a seemingly quiescent ∼5 × 108 M ⊙ galaxy in the early Universe: (i) stoc…
JWST Thermal Emission of the Terrestrial Exoplanet GJ 1132b
Eastman, Jason D.; Bean, Jacob L.; Zhang, Michael +9 more
We present thermal emission measurements of GJ 1132b spanning 5–12 µm obtained with the Mid-Infrared Instrument Low-Resolution Spectrometer on the James Webb Space Telescope. GJ 1132b is an M dwarf rocky planet with T eq = 584 K and an orbital period of 1.6 days. We measure a white-light secondary eclipse depth of 140 ± 17 ppm, wh…
Importance of Cosmic-Ray Propagation on Sub-GeV Dark Matter Constraints
De la Torre Luque, Pedro; Balaji, Shyam; Koechler, Jordan
We study sub-GeV dark matter (DM) particles that may annihilate or decay into Standard Model particles producing an exotic injection component in the Milky Way that leaves an imprint in both photon and cosmic-ray (CR) fluxes. Specifically, the DM particles may annihilate or decay into e + e ‑, µ + µ
Proper Motions and Orbits of Distant Local Group Dwarf Galaxies from a Combination of Gaia and Hubble Data
van der Marel, Roeland P.; Watkins, Laura L.; Sacchi, Elena +12 more
We have determined the proper motions (PMs) of 12 dwarf galaxies in the Local Group (LG), ranging from the outer Milky Way (MW) halo to the edge of the LG. We used the Hubble Space Telescope (HST) as the first and Gaia as the second epoch using the GaiaHub software. For Leo A and Sag DIG, we also used multi-epoch HST measurements relative to backg…
A Rest-frame Near-IR Study of Clumps in Galaxies at 1 < z < 2 Using JWST/NIRCam: Connection to Galaxy Bulges
Ho, Luis C.; Daddi, Emanuele; Bottrell, Connor +4 more
A key question in galaxy evolution has been the importance of the apparent "clumpiness" of high-redshift galaxies. Until now, this property has been primarily investigated in rest-frame UV, limiting our understanding of their relevance. Are they short-lived or are they associated with more long-lived massive structures that are part of the underly…
JWST Reveals a Luminous Infrared Source at the Position of the Failed Supernova Candidate N6946-BH1
Smith, Nathan; Sand, David J.; Jencson, Jacob E. +4 more
N6946-BH1 (BH1) is the first plausible candidate for a failed supernova (SN), a peculiar event in which a massive star disappears without the expected bright SN, accompanied by collapse into a black hole (BH). Following a luminous outburst in 2009, the source experienced a significant decline in optical brightness, while maintaining a persistent I…
Balmer Decrement Anomalies in Galaxies at z ∼ 6 Found by JWST Observations: Density-bounded Nebulae or Excited H I Clouds?
Ono, Yoshiaki; Ouchi, Masami; Nakagawa, Takao +11 more
We investigate the physical origins of the Balmer decrement anomalies in GS-NDG-9422 and RXCJ2248-ID galaxies at z ∼ 6 whose Hα/Hβ values are significantly smaller than 2.7, the latter of which also shows anomalous Hγ/Hβ and Hδ/Hβ values beyond the errors. Because the anomalous Balmer decrements are not reproduced under the Case B recombination, w…
Modeling the High-energy Ionizing Output from Simple Stellar and X-Ray Binary Populations
Johnson, Benjamin D.; Tzanavaris, Panayiotis; Jaskot, Anne +9 more
We present a methodology for modeling the joint ionizing impact due to a "simple X-ray population" (SXP) and its corresponding simple stellar population (SSP), where "simple" refers to a single age and metallicity population. We construct composite spectral energy distributions (SEDs) including contributions from ultraluminous X-ray sources and st…