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JWST detections of amorphous and crystalline HDO ice toward massive protostars
DOI: 10.1051/0004-6361/202449785 Bibcode: 2024A&A...688A..29S

Manoj, P.; Narang, Mayank; Bourke, Tyler L. +19 more

Context. Tracing the origin and evolution of interstellar water is key to understanding many of the physical and chemical processes involved in star and planet formation. Deuterium fractionation offers a window into the physicochemical history of water due to its sensitivity to local conditions.
Aims: The aim of this work is to utilize the in…

2024 Astronomy and Astrophysics
JWST 11
Cepheids as distance indicators and stellar tracers
DOI: 10.1007/s00159-024-00153-0 Bibcode: 2024A&ARv..32....4B

Bono, G.; Pietrinferni, A.; Braga, V. F.

We review the phenomenology of classical Cepheids (CCs), Anomalous Cepheids (ACs) and type II Cepheids (TIICs) in the Milky Way (MW) and in the Magellanic Clouds (MCs). We also examine the Hertzsprung progression in different stellar systems by using the shape of I-band light curves (Fourier parameters) and observables based on the difference in m…

2024 Astronomy and Astrophysics Review
Gaia 11
First JWST Observations of JAGB Stars in the SN Ia Host Galaxies: NGC 7250, NGC 4536, NGC 3972
DOI: 10.3847/1538-4357/ad12c7 Bibcode: 2024ApJ...961..132L

Madore, Barry F.; Freedman, Wendy L.; Jang, In Sung +2 more

The J-region Asymptotic Giant Branch (JAGB) method is a standard candle that leverages the constant luminosities of color-selected, carbon-rich AGB stars, measured in the near-infrared at 1.2 µm. The Chicago-Carnegie Hubble Program has obtained JWST imaging of the SN Ia host galaxies NGC 7250, NGC 4536, and NGC 3972. With these observations,…

2024 The Astrophysical Journal
JWST 11
Stellar Mergers or Truly Young? Intermediate-age Stars on Highly Radial Orbits in the Milky Way's Stellar Halo
DOI: 10.3847/1538-4357/ad58de Bibcode: 2024ApJ...971..170H

Price-Whelan, Adrian M.; Ness, Melissa K.; Horta, Danny +2 more

Reconstructing the mass assembly history of the Milky Way relies on obtaining detailed measurements of the properties of many stars in the galaxy, especially in the stellar halo. One of the most constraining quantities is stellar age, as it can shed light on the accretion time and quenching of star formation in merging satellites. However, obtaini…

2024 The Astrophysical Journal
Gaia 11
EMPRESS. XIV. Strong High-ionization Lines of Young Galaxies at z = 0–8: Ionizing Spectra Consistent with the Intermediate-mass Black Holes with M BH ∼ 103–106 M
DOI: 10.3847/1538-4357/ad335c Bibcode: 2024ApJ...966..170H

Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +16 more

We present ionizing spectra estimated at 13.6–100 eV for 10 dwarf galaxies with strong high-ionization lines of He II λ4686 and [Ne V] λ3426 ([Ne IV] λ2424) at z = 0 (z = 8) that are identified in our Keck/LRIS spectroscopy and the literature (the JWST Early Release Observations program). With the flux ratios of these high-ionization lines and >…

2024 The Astrophysical Journal
JWST 11
The TRGB-SBF Project. I. A Tip of the Red Giant Branch Distance to the Fornax Cluster with JWST
DOI: 10.3847/1538-4357/ad64c7 Bibcode: 2024ApJ...973...83A

Anand, Gagandeep S.; Blakeslee, John P.; Tully, R. Brent +7 more

Differences between the local value of the Hubble constant measured via the distance ladder versus the value inferred from the cosmic microwave background with the assumption of the standard ΛCDM model have reached over 5σ significance. To determine if this discrepancy is due to new physics or more mundane systematic errors, it is essential to rem…

2024 The Astrophysical Journal
JWST 11
Delayed X-Ray Brightening Accompanied by Variable Ionized Absorption Following a Tidal Disruption Event
DOI: 10.3847/1538-4357/ad1878 Bibcode: 2024ApJ...963...75W

Yao, Y.; Wevers, T.; Tombesi, F. +4 more

Supermassive black holes can experience super-Eddington peak mass fallback rates following the tidal disruption of a star. The theoretical expectation is that part of the infalling material is expelled by means of an accretion disk wind, whose observational signature includes blueshifted absorption lines of highly ionized species in X-ray spectra.…

2024 The Astrophysical Journal
XMM-Newton 11
Searching for electromagnetic emission in an AGN from the gravitational wave binary black hole merger candidate S230922g
DOI: 10.1103/PhysRevD.110.123029 Bibcode: 2024PhRvD.110l3029C

Valdes, Francisco; Andreoni, Igor; Graham, Matthew J. +18 more

We carried out long-term monitoring of the LIGO/Virgo/KAGRA binary black hole (BBH) merger candidate S230922g in search of electromagnetic emission from the interaction of the merger remnant with an embedding active galactic nuclei (AGN) accretion disk. Using a dataset primarily composed of wide-field imaging from the Dark Energy Camera and supple…

2024 Physical Review D
Gaia 11
New Insights on the Accretion Properties of Class 0 Protostars from 2 µm Spectroscopy
DOI: 10.3847/1538-4357/ad2935 Bibcode: 2024ApJ...966...91L

Le Gouellec, Valentin J. M.; Hillenbrand, Lynne A.; Greene, Thomas P. +1 more

Sun-like stars are thought to accrete most of their final mass during the protostellar phase, during which the stellar embryo is surrounded by an infalling dense envelope. We present an analysis of 26 K-band spectra of Class 0 protostars, which are the youngest protostars. Of these, 18 are new observations made with the Keck MOSFIRE instrument. H …

2024 The Astrophysical Journal
Herschel 11
Quantifying the Tension between Cosmological Models and JWST Red Candidate Massive Galaxies
DOI: 10.1088/1674-4527/ad2cd3 Bibcode: 2024RAA....24d5001W

Wang, Jun-Chao; Huang, Zhi-Qi; Huang, Lu +1 more

We develop a Python tool to estimate the tail distribution of the number of dark matter halos beyond a mass threshold and in a given volume in a light-cone. The code is based on the extended Press–Schechter model and is computationally efficient, typically taking a few seconds on a personal laptop for a given set of cosmological parameters. The hi…

2024 Research in Astronomy and Astrophysics
JWST 11