Search Publications
Nitrogen enhancements 440 Myr after the big bang: supersolar N/O, a tidal disruption event, or a dense stellar cluster in GN-z11?
Cameron, Alex J.; Saxena, Aayush; Katz, Harley +1 more
Recent observations of GN-z11 with JWST/NIRSpec revealed numerous oxygen, carbon, nitrogen, and helium emission lines at z = 10.6. Using the measured line fluxes, we derive abundance ratios of individual elements within the interstellar medium (ISM) of this superluminous galaxy. Driven by the unusually-bright N III] λ1750 and N IV] λ1486 emission …
Star formation histories of UV-luminous galaxies at z ≃ 6.8: implications for stellar mass assembly at early cosmic times
Charlot, Stéphane; Chevallard, Jacopo; Stark, Daniel P. +3 more
The variety of star formation histories (SFHs) of z ≳ 6 galaxies provides important insights into early star formation, but has been difficult to systematically quantify. Some observations suggest that many z ~ 6-9 galaxies are dominated by ≳200 Myr stellar populations, implying significant star formation at z ≳ 9, while others find that most reio…
A first look at the SMACS0723 JWST ERO: spectroscopic redshifts, stellar masses, and star-formation histories
Cullen, F.; McLure, R. J.; Dunlop, J. S. +9 more
We present a first-look analysis of the JWST ERO data in the SMACS J0723.3-7327 cluster field. We begin by reporting 10 new spectroscopic redshifts from λobs = 1.8-5.2 µm NIRSpec medium-resolution (R = λ/Δλ = 1000) data. These are determined via multiple high-SNR emission line detections with five objects at 1 < z < 3 displa…
Gaia Data Release 3. The Galaxy in your preferred colours: Synthetic photometry from Gaia low-resolution spectra
Prusti, T.; Mazeh, T.; Zucker, S. +442 more
Gaia Data Release 3 provides novel flux-calibrated low-resolution spectrophotometry for ≃220 million sources in the wavelength range 330 nm ≤ λ ≤ 1050 nm (XP spectra). Synthetic photometry directly tied to a flux in physical units can be obtained from these spectra for any passband fully enclosed in this wavelength range. We describe how synthetic…
Type Ia Supernova Explosions in Binary Systems: A Review
Han, Zhanwen; Liu, Zheng-Wei; Röpke, Friedrich K.
Type Ia supernovae (SNe Ia) play a key role in the fields of astrophysics and cosmology. It is widely accepted that SNe Ia arise from thermonuclear explosions of white dwarfs (WDs) in binary systems. However, there is no consensus on the fundamental aspects of the nature of SN Ia progenitors and their actual explosion mechanism. This fundamentally…
Early Results from GLASS-JWST. XIX. A High Density of Bright Galaxies at z ≈ 10 in the A2744 Region
Santini, Paola; Calabrò, Antonello; Castellano, Marco +38 more
We report the detection of a high density of redshift z ≈ 10 galaxies behind the foreground cluster A2744, selected from imaging data obtained recently with NIRCam on board JWST by three programs-GLASS-JWST, UNCOVER, and DDT#2756. To ensure robust estimates of the lensing magnification µ, we use an improved version of our model that exploits…
The JWST Hubble Sequence: The Rest-frame Optical Evolution of Galaxy Structure at 1.5 < z < 6.5
Wilkins, Stephen M.; Conselice, Christopher J.; Ferreira, Leonardo +13 more
We present results on the morphological and structural evolution of a total of 3956 galaxies observed with JWST at 1.5 < z < 6.5 in the JWST CEERS observations that overlap with the CANDELS EGS field. This is the biggest visually classified sample observed with JWST yet, ~20 times larger than previous studies, and allows us to examine in det…
Parameters of 220 million stars from Gaia BP/RP spectra
Rix, Hans-Walter; Zhang, Xiangyu; Green, Gregory M.
We develop, validate and apply a forward model to estimate stellar atmospheric parameters (Teff, log g, and [Fe/H]), revised distances and extinctions for 220 million stars with XP spectra from Gaia DR3. Instead of using ab initio stellar models, we develop a data-driven model of Gaia XP spectra as a function of the stellar parameters, …
Robust Data-driven Metallicities for 175 Million Stars from Gaia XP Spectra
Rix, Hans-Walter; Andrae, René; Chandra, Vedant
We derive and publish data-driven estimates of stellar metallicity [M/H] for ~175 million stars with low-resolution XP spectra published in Gaia DR3. The [M/H] values, along with T eff and $\mathrm{log}g$ , are derived using the XGBoost algorithm, trained on stellar parameters from APOGEE, augmented by a set of very-metal-poor stars. XG…
The PHANGS-JWST Treasury Survey: Star Formation, Feedback, and Dust Physics at High Angular Resolution in Nearby GalaxieS
Sandstrom, Karin M.; Bolatto, Alberto D.; Neumayer, Nadine +74 more
The PHANGS collaboration has been building a reference data set for the multiscale, multiphase study of star formation and the interstellar medium (ISM) in nearby galaxies. With the successful launch and commissioning of JWST, we can now obtain high-resolution infrared imaging to probe the youngest stellar populations and dust emission on the scal…