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A quasar-galaxy merger at z ∼ 6.2: Black hole mass and quasar properties from the NIRSpec spectrum
DOI: 10.1051/0004-6361/202348535 Bibcode: 2024A&A...685A.121L

Strauss, Michael A.; Fan, Xiaohui; Trebitsch, Maxime +31 more

We present JWST/NIRSpec integral field data of the quasar PJ308-21 at z = 6.2342. As shown by previous ALMA and HST imaging, the quasar has two companion sources, interacting with the quasar host galaxy. The high-resolution G395H/290LP NIRSpec spectrum covers the 2.87 − 5.27 µm wavelength range and shows the rest-frame optical emission of th…

2024 Astronomy and Astrophysics
JWST 23
Gaia DR3 detectability of unresolved binary systems
DOI: 10.1051/0004-6361/202450172 Bibcode: 2024A&A...688A...1C

Casey, Andrew R.; Rix, Hans-Walter; Brown, Anthony G. A. +10 more

Context.Gaia cannot individually resolve very close binary systems; however, the collected data can still be used to identify them. A powerful indicator of stellar multiplicity is the sources' reported re-normalised unit weight error (RUWE), which effectively captures the astrometric deviations from single-source solutions.
Aims: We aim to ch…

2024 Astronomy and Astrophysics
Gaia 23
Can we really pick and choose? Benchmarking various selections of Gaia Enceladus/Sausage stars in observations with simulations
DOI: 10.1093/mnras/stad3274 Bibcode: 2024MNRAS.527.2165C

Grand, Robert J. J.; Fattahi, Azadeh; Carrillo, Andreia +2 more

Large spectroscopic surveys plus Gaia astrometry have shown us that the inner stellar halo of the Galaxy is dominated by the debris of Gaia Enceladus/Sausage (GES). With the richness of data at hand, there are a myriad of ways these accreted stars have been selected. We investigate these GES selections and their effects on the inferred progenitor …

2024 Monthly Notices of the Royal Astronomical Society
Gaia 23
A new census of dust and polycyclic aromatic hydrocarbons at z = 0.7–2 with JWST MIRI
DOI: 10.1051/0004-6361/202449579 Bibcode: 2024A&A...690A..89S

Pérez-González, Pablo G.; D'Eugenio, Francesco; Bunker, Andrew J. +26 more

Aims. This paper utilises the James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) to extend the observational studies of dust and polycyclic aromatic hydrocarbon (PAH) emission to a new mass and star formation rate (SFR) parameter space beyond our local Universe. The combination of fully sampled spectral energy distributions (SEDs) wi…

2024 Astronomy and Astrophysics
eHST JWST 23
Small-scale stellar haloes: detecting low surface brightness features in the outskirts of Milky Way dwarf satellites
DOI: 10.1093/mnras/stad3322 Bibcode: 2024MNRAS.527.4209J

Smith, Simon E. T.; Hayes, Christian R.; Sestito, Federico +5 more

Dwarf galaxies are valuable laboratories for dynamical studies related to dark matter and galaxy evolution, yet it is currently unknown just how physically extended their stellar components are. Satellites orbiting the Galaxy's potential may undergo tidal stripping by the host, or alternatively, may themselves have accreted smaller systems whose d…

2024 Monthly Notices of the Royal Astronomical Society
Gaia 23
Ubiquitous broad-line emission and the relation between ionized gas outflows and Lyman continuum escape in Green Pea galaxies
DOI: 10.1051/0004-6361/202449175 Bibcode: 2024A&A...682L..25A

Chisholm, J.; Schaerer, D.; Marques-Chaves, R. +29 more

We report observational evidence of highly turbulent ionized gas kinematics in a sample of 20 Lyman continuum (LyC) emitters (LCEs) at low redshift (z ∼ 0.3). Detailed Gaussian modeling of optical emission line profiles in high-dispersion spectra consistently shows that both bright recombination and collisionally excited lines can be fitted as one…

2024 Astronomy and Astrophysics
eHST 23
SN 2023ixf in Messier 101: The Twilight Years of the Progenitor as Seen by Pan-STARRS
DOI: 10.3847/1538-4357/ad2df7 Bibcode: 2024ApJ...965...93R

Kilpatrick, Charles D.; Chambers, Kenneth C.; Coulter, David A. +28 more

The nearby type II supernova, SN 2023ixf in M101 exhibits signatures of early time interaction with circumstellar material in the first week postexplosion. This material may be the consequence of prior mass loss suffered by the progenitor, which possibly manifested in the form of a detectable presupernova outburst. We present an analysis of long-b…

2024 The Astrophysical Journal
eHST 23
A massive compact quiescent galaxy at z = 2 with a complete Einstein ring in JWST imaging
DOI: 10.1038/s41550-023-02103-9 Bibcode: 2024NatAs...8..119V

van Dokkum, Pieter; Conroy, Charlie; Brammer, Gabriel +2 more

One of the surprising results from the Hubble Space Telescope was the discovery that many of the most massive galaxies at redshift z ≈ 2 are very compact, having a half-light radius of only 1‑2 kpc. The interpretation is that massive galaxies formed inside out, with their cores largely in place by z ≈ 2 and approximately half of their present-day …

2024 Nature Astronomy
eHST JWST 23
The CO-to-H2 conversion factor of molecular outflows. Rovibrational CO emission in NGC 3256-S resolved by JWST/NIRSpec
DOI: 10.1051/0004-6361/202347942 Bibcode: 2024A&A...681A.117P

Rigopoulou, D.; García-Burillo, S.; González-Alfonso, E. +2 more

We analyze JWST/NIRSpec observations of the CO rovibrational υ = 1−0 band at ~4.67 µm around the dust-embedded southern active galactic nucleus (AGN) of NGC 3256 (d = 40 Mpc; LIR = 1011.6 L). We classify the CO υ = 1−0 spectra into three categories based on the behavior of P- and R-branches of the band: (a) both b…

2024 Astronomy and Astrophysics
JWST 23
200 000 candidate very metal-poor stars in Gaia DR3 XP spectra
DOI: 10.1093/mnras/stad3775 Bibcode: 2024MNRAS.52710937Y

Limberg, Guilherme; Ji, Alexander P.; Koposov, Sergey E. +1 more

Very metal-poor stars ($\rm [Fe/H] \lt -2$) in the Milky Way are fossil records of early chemical evolution and the assembly and structure of the Galaxy. However, they are rare and hard to find. Gaia DR3 has provided over 200 million low-resolution (R ≈ 50) XP spectra, which provides an opportunity to greatly increase the number of candidate metal…

2024 Monthly Notices of the Royal Astronomical Society
Gaia 22