Publications de Michaela Hirschmann

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

CAPERS-LRD-z9: A Gas-enshrouded Little Red Dot Hosting a Broad-line Active Galactic Nucleus at z = 9.288

Michaela Hirschmann

We present CAPERS-LRD-z9, a little red dot (LRD) that we confirm to be a z = 9.288 broad-line active galactic nucleus (BLAGN). First identified as a high-redshift LRD candidate from PRIMER NIRCam photometry, follow-up NIRSpec/PRISM spectroscopy of CAPERS-L ...

2025

The Cosmic Evolution Early Release Science Survey (CEERS)

Michaela Hirschmann

We present the Cosmic Evolution Early Release Science (CEERS) Survey, a 77.2 hr Director’s Discretionary Early Release Science Program. CEERS demonstrates, tests, and validates efficient extragalactic surveys using coordinated, overlapping parallel observa ...

2025

Investigating the Impact of Supernova Feedback on Satellites in Elliptical Galaxies

Michaela Hirschmann

We investigate the influence of supernova (SN) feedback on the satellites of elliptical host galaxies using hydrodynamic simulations. Utilizing a modified version of the GADGET-3 code, we perform cosmological zoom-in simulations of 11 elliptical galaxies w ...

2025

Evolution of the UV slope of galaxies at cosmic morning (z > 4): The properties of extremely blue galaxies

Michaela Hirschmann

We present an analysis of the UV continuum slope, β, using a sample of 726 galaxies with z > 4, selected from a mixture of JWST ERS, GTO, and GO observational programs. We considered only spectroscopic data obtained with the low-resolution (R ∼ 30−300) PRI ...

2025

Rubies: Jwst/nirspec Confirmation of an Infrared-luminous, Broad-line Little Red Dot with an Ionized Outflow

Michaela Hirschmann

The JWST discovery of "little red dots" (LRDs) is reshaping our picture of the early Universe, yet the physical mechanisms driving their compact size and UV-optical colors remain elusive. Here, we report an unusually bright LRD (zspec = 3.1) observed as pa ...

IOP Publishing Ltd2025

SCUBADive. I. JWST plus ALMA Analysis of 289 Submillimeter Galaxies in COSMOS-web

Michaela Hirschmann

JWST has enabled detecting and spatially resolving the heavily dust-attenuated stellar populations of submillimeter galaxies, revealing detail that was previously inaccessible. In this work, we construct a sample of 289 submillimeter galaxies with joint At ...

IOP Publishing Ltd2025

Broad-line AGNs at 3.5 < z < 6: The Black Hole Mass Function and a Connection with Little Red Dots

Michaela Hirschmann

We present a sample of 62 Hα detected broad-line active galactic nuclei (BLAGNs) at redshifts 3.5 < z < 6.8 using data from the CEERS and RUBIES surveys. We select these sources directly from JWST/NIRSpec G395M/F290LP spectra. We use a multistep pre-select ...

2025

Compact dust-obscured star formation and the origin of the galaxy bimodality

Michaela Hirschmann

Context. The combined capabilities of the James Webb Space Telescope/Near Infrared Camera (NIRCam) and the Hubble Space Telescope/Advanced Camera for Surveys (ACS) instruments provide high-angular-resolution imaging from the ultraviolet to near-infrared (U ...

2025