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Spectroscopic Confirmation of Obscured AGN Populations from Unsupervised Machine Learning
DOI: 10.3847/1538-3881/ad28b4 Bibcode: 2024AJ....167..169H

Greene, Jenny E.; Goulding, Andy D.; Hainline, Kevin N. +1 more

We present the result of a spectroscopic campaign targeting active galactic nucleus (AGN) candidates selected using a novel unsupervised machine-learning (ML) algorithm trained on optical and mid-infrared photometry. AGN candidates are chosen without incorporating prior AGN selection criteria and are fainter, redder, and more numerous, ∼340 AGN de…

2024 The Astronomical Journal
Gaia 6
Methods for the Detection of Stellar Rotation Periods in Individual TESS Sectors and Results from the Prime Mission
DOI: 10.3847/1538-3881/ad2c86 Bibcode: 2024AJ....167..189C

Angus, Ruth; Curtis, Jason; David, Trevor +3 more

For ongoing studies of the role of rotation in stellar evolution, we require large catalogs of rotation periods for testing and refining gyrochronology. While there is a wealth of data from the Kepler and K2 missions, the Transiting Exoplanet Survey Satellite (TESS) presents both an opportunity and a challenge: despite its all-sky coverage, rotati…

2024 The Astronomical Journal
Gaia 6
The asymmetric bipolar [Fe II] jet and H2 outflow of TMC1A resolved with the JWST NIRSpec Integral Field Unit
DOI: 10.1051/0004-6361/202449745 Bibcode: 2024A&A...688A..26A

Pontoppidan, K. M.; Bjerkeli, P.; Kristensen, L. E. +10 more

Context. Protostellar outflows exhibit large variations in their structure depending on the observed gas emission. To understand the origin of the observed variations, it is important to analyze the differences in the observed morphology and kinematics of the different tracers. The James Webb Space Telescope (JWST) allows us to study the physical …

2024 Astronomy and Astrophysics
JWST 6
A fast-cadenced search for gamma-ray burst orphan afterglows with the Deeper, Wider, Faster programme
DOI: 10.1093/mnras/stae1489 Bibcode: 2024MNRAS.531.4836F

Auchettl, Katie; Allen, Rebecca; Andreoni, Igor +11 more

The relativistic outflows that produce long gamma-ray bursts (LGRBs) can be described by a structured jet model where prompt $\gamma$-ray emission is restricted to a narrow region in the jet's core. Viewing the jet off-axis from the core, a population of afterglows without an associated GRB detection can be predicted. In this work, we conduct an a…

2024 Monthly Notices of the Royal Astronomical Society
Gaia 6
The TESS-Keck Survey. XVII. Precise Mass Measurements in a Young, High-multiplicity Transiting Planet System Using Radial Velocities and Transit Timing Variations
DOI: 10.3847/1538-3881/ad1330 Bibcode: 2024AJ....167...70B

Batalha, Natalie M.; Mayo, Andrew W.; Rice, Malena +41 more

We present a radial velocity (RV) analysis of TOI-1136, a bright Transiting Exoplanet Survey Satellite (TESS) system with six confirmed transiting planets, and a seventh single-transiting planet candidate. All planets in the system are amenable to transmission spectroscopy, making TOI-1136 one of the best targets for intra-system comparison of exo…

2024 The Astronomical Journal
Gaia 6
The R-Process Alliance: detailed chemical composition of an r-process enhanced star with UV and optical spectroscopy
DOI: 10.1093/mnras/stae255 Bibcode: 2024MNRAS.529.1917S

Beers, Timothy C.; Placco, Vinicius M.; Holmbeck, Erika M. +8 more

We present a detailed chemical-abundance analysis of a highly r-process-enhanced (RPE) star, 2MASS J00512646-1053170, using high-resolution spectroscopic observations with Hubble Space Telescope/STIS in the UV and Magellan/MIKE in the optical. We determined abundances for 41 elements in total, including 23 r-process elements and rarely probed spec…

2024 Monthly Notices of the Royal Astronomical Society
eHST 6
Obscured star formation in clusters at z = 1.6-2.0: massive galaxy formation and the reversal of the star formation-density relation
DOI: 10.1093/mnras/stae692 Bibcode: 2024MNRAS.529.2290S

Smail, Ian

Clusters of galaxies at z $\mathrel {\gtrsim }$ 1 are expected to be increasingly active sites of star formation. To test this, an 850 $\mu$m survey was undertaken of eight clusters at z = 1.6-2.0 using SCUBA-2 on the James Clerk Maxwell Telescope. Mid-infrared properties were used to identify 53 probable counterparts to 45 SCUBA-2 sources with co…

2024 Monthly Notices of the Royal Astronomical Society
eHST 6
A SPectroscopic Survey of Biased Halos In the Reionization Era (ASPIRE): JWST Supports Earlier Reionization around [O III] Emitters
DOI: 10.3847/1538-4357/ad82de Bibcode: 2024ApJ...976...93J

Hennawi, Joseph F.; Fan, Xiaohui; Cai, Zheng +22 more

Understanding when and how reionization happened is crucial for studying the early structure formation and the properties of the first galaxies in the Universe. At z > 5.5, the observed intergalactic medium (IGM) optical depth shows a significant scatter, indicating an inhomogeneous reionization process. However, the nature of the inhomogeneous…

2024 The Astrophysical Journal
JWST 6
Comparative Study of the Kinetic Properties of Proton and Alpha Beams in the Alfvénic Wind Observed by SWA-PAS On Board Solar Orbiter
DOI: 10.3847/1538-4357/ad47b3 Bibcode: 2024ApJ...969..106B

Telloni, Daniele; Sorriso-Valvo, Luca; Marino, Raffaele +12 more

The problems of heating and acceleration of solar wind particles are of significant and enduring interest in astrophysics. The interactions between waves and particles are crucial in determining the distributions of proton and alpha particles, resulting in non-Maxwellian characteristics, including temperature anisotropies and particle beams. These…

2024 The Astrophysical Journal
SolarOrbiter 6
Revisiting the Helium and Hydrogen Accretion Indicators at TWA 27B: Weak Mass Flow at Near-freefall Velocity
DOI: 10.3847/1538-4357/ad1ee9 Bibcode: 2024ApJ...964...70M

Zhou, Yifan; Hashimoto, Jun; Marleau, Gabriel-Dominique +1 more

TWA 27B (2M1207b) is the first directly imaged planetary-mass (M p ≈ 5 M J) companion and was observed at 0.9–5.3 µm with JWST/NIRSpec. To understand the accretion properties of TWA 27B, we search for continuum-subtracted near-infrared helium and hydrogen emission lines and measure their widths and luminosities. We dete…

2024 The Astrophysical Journal
eHST JWST 6