Search Publications
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…
JWST Imaging of Edge-on Protoplanetary Disks. II. Appearance of Edge-on Disks with a Tilted Inner Region: Case Study of IRAS04302+2247
Duchêne, Gaspard; Wolff, Schuyler G.; Perrin, Marshall D. +6 more
We present James Webb Space Telescope imaging from 2 to 21 µm of the edge-on protoplanetary disk around the embedded young star IRAS04302+2247. The structure of the source shows two reflection nebulae separated by a dark lane. The source extent is dominated by the extended filamentary envelope at ~4.4 µm and shorter wavelengths, transi…
UVCANDELS: The Role of Dust on the Stellar Mass–Size Relation of Disk Galaxies at 0.5 ≤ z ≤ 3.0
Grogin, Norman A.; Koekemoer, Anton M.; Lucas, Ray A. +30 more
We use the Ultraviolet Imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey fields (UVCANDELS) to measure half-light radii in the rest-frame far-UV for ∼16,000 disk-like galaxies over 0.5 ≤ z ≤ 3. We compare these results to rest-frame optical sizes that we measure in a self-consistent way and find that the stellar mass–si…
JWST Spectroscopy of SN H0pe: Classification and Time Delays of a Triply Imaged Type Ia Supernova at z = 1.78
Grogin, Norman A.; Koekemoer, Anton M.; Frye, Brenda L. +19 more
SN H0pe is a triply imaged supernova (SN) at redshift z = 1.78 discovered using the James Webb Space Telescope. In order to classify the SN spectroscopically and measure the relative time delays of its three images (designated A, B, and C), we acquired NIRSpec follow-up spectroscopy spanning 0.6–5 µm. From the high signal-to-noise spectra of…
The Fraction of Dust Mass in the Form of Polycyclic Aromatic Hydrocarbons on 10–50 pc Scales in Nearby Galaxies
Ramambason, Lise; Leroy, Adam K.; Rosolowsky, Erik +21 more
Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous component of the interstellar medium (ISM) in z ∼ 0 massive, star-forming galaxies and play key roles in ISM energy balance, chemistry, and shielding. Wide field-of-view, high-resolution mid-infrared (MIR) images from JWST provide the ability to map the fraction of dust in the form of PAHs a…