Publications associées à Discovery of a Rare Group of Dwarf Galaxies in the Local Universe

Publications associées (29)

Euclid: A complete Einstein ring in NGC 6505

Frédéric Courbin, Georges Meylan, Benjamin Yvan Alexandre Clement, Javier Alejandro Acevedo Barroso

We report the discovery of a complete Einstein ring around the elliptical galaxy NGC 6505, at z = 0.042. This is the first strong gravitational lens discovered in Euclid and the first in an NGC object from any survey. The combination of the low redshift of ...

2025

Ambipolar diffusion and the mass-to-flux ratio in a turbulent collapsing cloud

Aris Evangelos Tritsis

Context. The formation of stars is governed by the intricate interplay of nonideal magnetohydrodynamic (MHD) effects, gravity, and turbulence. Computational challenges have hindered a comprehensive 3D exploration of this interplay, posing a longstanding ch ...

2025

Euclid preparation: LXVII. Deep learning true galaxy morphologies for weak lensing shear bias calibration

Frédéric Courbin, Georges Meylan

To date, galaxy image simulations for weak lensing surveys usually approximate the light profiles of all galaxies as a single or double Sérsic profile, neglecting the influence of galaxy substructures and morphologies deviating from such a simplified param ...

2025

The importance of nuclear star clusters for massive black hole growth and nuclear star formation in simulated low-mass galaxies

Michaela Hirschmann, Jonathan Erik Peter Petersson

Observed low-mass galaxies with nuclear star clusters (NSCs) can host accreting massive black holes (MBH). We present simulations of dwarf galaxies (M-baryon similar to 0.6-2.4x10(8)M(circle dot)) at solar mass resolution (0.5M(circle dot)

OXFORD UNIV PRESS2025

The MBH-M∗ Relation up to z ∼ 2 through Decomposition of COSMOS-Web NIRCam Images

Michaela Hirschmann

Our knowledge of relations between supermassive black holes and their host galaxies at z greater than or similar to 1 is still limited, even though being actively sought out to z similar to 6. Here, we use the high resolution and sensitivity of JWST to mea ...

IOP Publishing Ltd2025

Optimal reconstruction of baryon acoustic oscillations for DESI 2024

Jiaxi Yu

Baryon acoustic oscillations (BAO) provide a robust standard ruler to measure the expansion history of the Universe through galaxy clustering. Density-field reconstruction is now a widely adopted procedure for increasing the precision and accuracy of the B ...

2025

Radio halo detection in MWA data using deep neural networks and generative data augmentation

Jean-Paul Richard Kneib, Emma Elizabeth Tolley, Shreyam Parth Krishna, Ashutosh Kumar Mishra

Detecting diffuse radio emission, such as from haloes, in galaxy clusters is crucial for understanding large-scale structure formation in the universe. Traditional methods, which rely on X-ray and Sunyaev-Zeldovich (SZ) cluster pre-selection, introduce bia ...

OXFORD UNIV PRESS2025

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

Adèle Marie Françoise Plat

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

Variable stars in galactic globular clusters I. The population of RR Lyrae stars

Zoé Lisa Medaric, Richard Irving Anderson, Mauricio Cruz Reyes, Henryka Ewa Netzel

We present a comprehensive catalog of 2824 RR Lyrae stars (RRLs) residing in 115 Galactic globular clusters (GCs). Our catalog includes 1594 fundamental-mode (RRab), 824 first-overtone (RRc), and 28 double-mode (RRd) RRLs, as well as 378 RRLs of an unknown ...

Edp Sciences S A2024

Magnetic field morphology and evolution in the Central Molecular Zone and its effect on gas dynamics

Michaela Hirschmann, Robin Gopala Tress

The interstellar medium in the Milky Way's Central Molecular Zone (CMZ) is known to be strongly magnetised, but its large-scale morphology and impact on the gas dynamics are not well understood. We explore the impact and properties of magnetic fields in th ...

EDP SCIENCES S A2024

Discovery of a dormant 33 solar-mass black hole in pre-release Gaia astrometry

Richard Irving Anderson, Mauricio Cruz Reyes

Context. Gravitational waves from black-hole (BH) merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models-And also higher than known ...

2024

The stellar mass function of quiescent galaxies in 2 < z < 2.5 protoclusters

Pascale Jablonka, Michaela Hirschmann, Yannick Michael Bahé

We present an analysis of the galaxy stellar mass function (SMF) of 14 known protoclusters between 2.0 < z < 2.5 in the COSMOS field, down to a mass limit of 10(9.5) M⊙. We use existing photometric redshifts with a statistical background subtraction, and c ...

Oxford Univ Press2023

New dwarf galaxy candidates in the sphere of influence of the Local Volume spiral galaxy NGC2683

Oliver Müller

We present initial results of a survey of host L-* galaxies environments in the Local Volume (D < 10 Mpc) searching for satellite dwarf galaxy candidates using the wide-field Hyper Suprime-Cam imager on the 8 m Subaru Telescope. This paper presents complet ...

2023

An Atlas of Color-selected Quiescent Galaxies at z > 3 in Public JWST Fields

Michaela Hirschmann, Minju Lee

We present the results of a systematic search for candidate quiescent galaxies in the distant universe in 11 JWST fields with publicly available observations collected during the first 3 months of operations and covering an effective sky area of similar to ...

IOP Publishing Ltd2023

Dynamics of stellar disc tilting from satellite mergers

Timothy Cohen

The Milky Way's stellar disc can tilt in response to torques that result from infalling satellite galaxies and their associated tidal debris. In this work, we explore the dynamics of disc tilting by running N-body simulations of mergers in an isolated, iso ...

2023

Spectral Templates Optimal for Selecting Galaxies at z > 8 with the JWST

Michaela Hirschmann

The selection of high-redshift galaxies often involves spectral energy distribution (SED) fitting to photometric data, an expectation for contamination levels, and measurement of sample completeness-all vetted through comparison to spectroscopic redshift m ...

Iop Publishing Ltd2023

The creation of a massive UCD by tidal threshing from NGC936

Oliver Müller, Nick Heesters

We study a compact nucleus embedded in an early-type dwarf galaxy, MATLAS-167, which is in the process of disruption by the tidal force of the neighbouring giant S0 galaxy, NGC936, in a group environment. Using the imaging data of the MATLAS survey, we ana ...

Oxford Univ Press2023

The Local Cluster Survey II: disc-dominated cluster galaxies with suppressed star formation

Pascale Jablonka

We investigate the role of dense environments in suppressing star formation by studying log(10)(M- * / M-?) > 9 . 7 star-forming galaxies in nine clusters from the Local Cluster Survey (0.0137 < z < 0.0433) and a large comparison field sample drawn from th ...

OXFORD UNIV PRESS2023

Euclid preparation XXII. Selection of quiescent galaxies from mock photometry using machine learning

Maurizio Martinelli, Frédéric Courbin, Georges Meylan, Gianluca Castignani, Austin Chandler Peel

The Euclid Space Telescope will provide deep imaging at optical and near-infrared wavelengths, along with slitless near-infrared spectroscopy, across similar to 15 000deg(2) of the sky. Euclid is expected to detect similar to 12 billion astronomical source ...

EDP SCIENCES S A2023

New dwarf galaxy candidates in the sphere of influence of the Sombrero galaxy

Oliver Müller

We report the discovery of 40 new satellite dwarf galaxy candidates in the sphere of influence of the Sombrero Galaxy (M104), the most luminous galaxy in the Local Volume. Using the Subaru Hyper Suprime-Cam, we surveyed 14.4 deg(2) of its surroundings, ext ...

Oxford Univ Press2023