Publications associées à HD 213258: A new rapidly oscillating, super slowly rotating, strongly magnetic Ap star in a spectroscopic binary

CLASSY. VIII. Exploring the Source of Ionization with UV Interstellar Medium Diagnostics in Local High-z Analogs

In the current JWST era, rest-frame UV spectra play a crucial role in enhancing our understanding of the interstellar medium (ISM) and stellar properties of the first galaxies in the epoch of reionization (z > 6). Here, we compare well-known and reliable o ...

Iop Publishing Ltd2024

Hidden Gems on a Ring: Infant Massive Clusters and Their Formation Timeline Unveiled by ALMA, HST, and JWST in NGC 3351

Hamid Hassani, Hao He, Robin Gopala Tress, Jiayi Sun

We use 0.1 '' observations from the Atacama Large Millimeter Array (ALMA), Hubble Space Telescope (HST), and JWST to study young massive clusters (YMCs) in their embedded "infant" phase across the central starburst ring in NGC 3351. Our new ALMA data revea ...

Iop Publishing Ltd2024

Tracing the rise of supermassive black holes A panchromatic search for faint, unobscured quasars at z ≥ 6 with COSMOS-Web and other surveys

Michaela Hirschmann

We report the identification of 64 new candidates of compact galaxies, potentially hosting faint quasars with bolometric luminosities of L-bol = 10(43)-10(46) erg s(-1), residing in the reionization epoch within the redshift range of 6 less than or similar ...

Edp Sciences S A2024

COSMOS-Web: Intrinsically Luminous z ≳ 10 Galaxy Candidates Test Early Stellar Mass Assembly

Michaela Hirschmann

We report the discovery of 15 exceptionally luminous 10 less than or similar to z less than or similar to 14 candidate galaxies discovered in the first 0.28 deg(2) of JWST/NIRCam imaging from the COSMOS-Web survey. These sources span rest-frame UV magnitud ...

Iop Publishing Ltd2024

Stellar Metallicities and Gradients in the Isolated, Quenched Low-mass Galaxy Tucana

Nicolas Lawrence Etienne Longeard

We measure the metallicities of 374 red giant branch (RGB) stars in the isolated, quenched dwarf galaxy Tucana using Hubble Space Telescope (HST) narrow-band (F395N) Calcium H & K (CaHK) imaging. Our sample is a factor of similar to 7 similar to 7 larger t ...

Iop Publishing Ltd2024

Evolution of the Size-Mass Relation of Star-forming Galaxies Since z=5.5 Revealed by CEERS

Michaela Hirschmann

We combine deep imaging data from the CEERS early release JWST survey and Hubble Space Telescope imaging from CANDELS to examine the size-mass relation of star-forming galaxies and the morphology-quenching relation at stellar masses M-star >= 10(9.5)M(circ ...

Iop Publishing Ltd2024

Extremely Red Galaxies at z=5-9 with MIRI and NIRSpec: Dusty Galaxies or Obscured Active Galactic Nuclei?

Michaela Hirschmann

We study a new population of extremely red objects (EROs) recently discovered by the James Webb Space Telescope (JWST) based on their NIRCam colors F277W - F444W > 1.5 mag. We find 37 EROs in the Cosmic Evolution Early Release Science Survey (CEERS) field ...

Iop Publishing Ltd2024

The Origins of Gas Accreted by Supermassive Black Holes: The Importance of Recycled Gas

Michaela Hirschmann

We investigate the fueling mechanisms of supermassive black holes (SMBHs) by analyzing 10 zoom-in cosmological simulations of massive galaxies, with stellar masses 1011-12 M circle dot and SMBH masses 108.9-9.7 M circle dot at z = 0, featuring various majo ...

Iop Publishing Ltd2024

White dwarfs as a probe of exceptionally light QCD axions

We study the effects of exceptionally light QCD axions on the stellar configuration of white dwarfs. At finite baryon density, the nonderivative coupling of the axion to nucleons displaces the axion from its invacuum minimum, which implies a reduction of t ...

American Physical Society2024

GHOST commissioning science results - II: a very metal-poor star witnessing the early galactic assembly

Pascale Jablonka

This study focuses on Pristine_180956.78-294759.8 (hereafter P180956, [Fe/H] = -1.95 +/- 0.02), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up with the recently commissioned Gemini High-resolution Optical SpecTrograph (GHOST) ...

Oxford Univ Press2024

Small-amplitude Red Giants Elucidate the Nature of the Tip of the Red Giant Branch as a Standard Candle

Richard Irving Anderson, Nolan Wayne Koblischke

The tip of the red giant branch (TRGB) is an important standard candle for determining luminosity distances. Although several 105 small-amplitude red giant stars (SARGs) have been discovered, variability was previously considered irrelevant for the TRGB as ...

Iop Publishing Ltd2024

Shedding light on the MRI-driven dynamo in a stratified shearing box

Abhijit Bhausaheb Bendre

We study the magneto-rotational instability (MRI) dynamo in a geometrically thin disc (H/R < 1) using stratified zero net (vertical) flux shearing box simulations. We find that mean fields and electromotive forces (EMFs) oscillate with a primary frequency ...

2024

The Complete CEERS Early Universe Galaxy Sample: A Surprisingly Slow Evolution of the Space Density of Bright Galaxies at z ∼ 8.5-14.5

Michaela Hirschmann

We present a sample of 88 candidate z similar to 8.5-14.5 galaxies selected from the completed NIRCam imaging from the Cosmic Evolution Early Release Science survey. These data cover similar to 90 arcmin2 (10 NIRCam pointings) in six broadband imaging filt ...

Iop Publishing Ltd2024

The AGORA High-resolution Galaxy Simulations Comparison Project. V. Satellite Galaxy Populations in a Cosmological Zoom-in Simulation of a Milky Way-Mass Halo

Yves Revaz, Loïc Hausammann, Alessandro Lupi

We analyze and compare the satellite halo populations at z similar to 2 in the high-resolution cosmological zoom-in simulations of a 1012 M circle dot target halo (z = 0 mass) carried out on eight widely used astrophysical simulation codes (Art-I, Enzo, Ra ...

Iop Publishing Ltd2024

The formation of the faintest galaxies in cosmological simulations: from the impact of primordial magnetic fields to the metal enrichment of present day dwarfs by first stars

Mahsa Sanati

In the theory of the bottom-up assembly of cosmic structures, one of the main challenges is to connect the smallest, most inconspicuous galaxies we observe today to the building blocks of more massive galaxies such as our own, the Milky Way. Do these so-ca ...

EPFL2023

A possible dwarf galaxy satellite-of-satellite problem in ?CDM

Yves Revaz, Nick Heesters

Dark matter clusters on all scales, and it is therefore expected that even substructure should host its own substructure. Using the Extragalactic Distance Database, we searched for dwarf-galaxy satellites of dwarf galaxies, that is, satellite-of-satellite ...

EDP SCIENCES S A2023

A model for the infrared-radio correlation of main sequence galaxies at gigahertz frequencies and its variation with redshift and stellar mass

Jennifer Waltraud Schober, Mark Thomas Sargent

Context. The infrared-radio correlation (IRRC) of star-forming galaxies can be used to estimate their star formation rate (SFR) based on the radio continuum luminosity at MHz-GHz frequencies. For its practical application in future deep radio surveys, it i ...

Edp Sciences S A2023

Gaia Focused Product Release: Spatial distribution of two diffuse interstellar bands

Stephan Morgenthaler, Shuangqing Liao

Diffuse interstellar bands (DIBs) are absorption features seen in optical and infrared spectra of stars and extragalactic objects that are probably caused by large and complex molecules in the galactic interstellar medium (ISM). Here we investigate the Gal ...

Edp Sciences S A2023

Expanding on the fundamental metallicity relation in dwarf galaxies with MUSE

Oliver Müller

The mass-metallicity relation (MZR) represents one of the most important scaling relations in the context of galaxy evolution, comprising a positive correlation between stellar mass and metallicity (Z). The fundamental metallicity relation (FMR) introduces ...

Edp Sciences S A2023

How much metal did the first stars provide to the ultra-faint dwarfs?

Yves Revaz, Pascale Jablonka, Mahsa Sanati

Numerical simulations of dwarf galaxies have so far failed to reproduce the observed metallicity-luminosity relation, down to the regime of ultra-faint dwarfs (UFDs). We address this issue by exploring how the first generations of metal-free stars (Pop III ...

EDP SCIENCES S A2023