Space Telescope Science Institute

The Evolution of Low-ionization Electron Densities in Galaxies across Cosmic Epochs

Abstract We investigate the low-ionization electron density in the interstellar medium (ISM) of galaxies across 0 < z < 8, derived with the [O ii ] λλ 3727, 3730 and [S ii ] λλ 6718, 6733 doublets, using both deep JWST/NIRCam/grism and NIRSpec/MSA spectroscopy. Along with ancilla...

Constraining Dust Formation in the Superluminous Supernova 2017gci with JWST Observations

Abstract We present JWST/MIRI observations of the Type I superluminous supernova (SLSN) 2017gci obtained over 2000 rest-frame days after the supernova (SN) exploded, which represent the latest phase images taken of any known SLSN to date. We find that archival Wide-field Infrared...

Breaking the Blend: A multi-tracer kinematic decomposition method for IFS data applied to disentangling the AGN outflow and circumnuclear ring in NGC 5728 with JWST

Abstract Integral field spectroscopy (IFS) of the central kiloparsecs of active galactic nuclei (AGN) reveals a mixture of spatially coincident emission from star-formation and AGN feedback exciting the interstellar medium. Disentangling these components remains a challenge, as m...

Discovery of a second-generation planet candidate accreting onto a white dwarf

Abstract Many white dwarfs accrete the debris of disrupted planetary bodies, detected in the form of metal enrichment in their atmospheres, dusty or gaseous circumstellar discs, and photometric transits from debris. The composition of accreted debris has been shown to be diverse...

JWST Nebular Spectroscopy of SN 2023qov: Circumstellar Dust Emission in a Normal Type Ia Supernova

Abstract We present panchromatic observations of the Type Ia supernova (SN Ia) 2023qov, ranging from ∼2 weeks before to ∼1 yr after maximum light. JWST near- and mid-infrared spectra at +276 and +363 days show ∼400 K dust emission that cools by ∼75 K between epochs, the first una...

Growth of aromatic hydrocarbon dust particles in the extremely metal-poor galaxy Sextans A

The mid-infrared spectrum of star-forming, high-metallicity galaxies is dominated by emission features from aromatic and aliphatic bonds in small carbonaceous dust grains, often referred to as polycyclic aromatic hydrocarbons (PAHs). In metal-poor galaxies, the abundance of PAHs...

SN 2024iss: A Multiwavelength Exposé of a Type IIb Supernova with an Early-time Ultraviolet Spectrum and Shock-breakout Constraints

Abstract We present multiwavelength observations and analysis of SN 2024iss, a Type IIb supernova (SN IIb) located at ∼14 Mpc. The first Zwicky Transient Facility detection of SN 2024iss is ∼40 minutes after first light (one of the earliest detections of a SN IIb to date) and a H...

The Neutral Hydrogen Gas Content of Star-forming and Quiescent S0 Galaxies

Abstract Lenticular (or S0) galaxies that remain actively star-forming (SFS0s) are a unique transition population among galaxies. We investigated the HI (21cm) neutral hydrogen content of a sample of lenticular galaxies identified from within the Mapping Nearby Galaxies at Apache...

The Luminosity Function of Ultrafaint Trans-Neptunian Objects Detected by JWST

Abstract We present a definitive discovery of 27 trans-Neptunian objects (TNOs) using the Near-Infrared Camera aboard the James Webb Space Telescope (JWST). By employing a shift-and-stack technique and a machine learning network geared specifically to identifying false-positive d...

The Star Formation History and Evolution of the Ultra-Diffuse M81 Satellite F8D1

Abstract We present deep Hubble Space Telescope (HST) imaging of one of the nearest ultra-diffuse galaxies (UDGs) outside of the Local Group: F8D1, a satellite of M81 known to be tidally disrupting. UDGs are an enigmatic and diverse population, with evolutionary pathways ranging...

Evidence of a massive accretion event 1.8 billion years before the Gaia-Sausage-Enceladus merger

Abstract The merger history of the Galaxy has been traced back firmly to a redshift of 2 (10 billion years ago). While evidence for the existence of at least one more substantial merger before this time has been presented, its interpretation is yet to be fully established. Here w...