Mélanie Habouzit
A5062081510- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Relativity and Gravitational Theory
- Black Holes and Theoretical Physics
- Astrophysics and Star Formation Studies
- History and Developments in Astronomy
- Advanced Measurement and Metrology Techniques
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Statistics Education and Methodologies
- Scientific Research and Discoveries
- Sports Dynamics and Biomechanics
- Plant Water Relations and Carbon Dynamics
- Photonic Crystal and Fiber Optics
- Historical Astronomy and Related Studies
- CCD and CMOS Imaging Sensors
University of Geneva
2024-2025
Max Planck Institute for Astronomy
2019-2025
University of Maryland, College Park
2023-2024
Heidelberg University
2020-2024
Joint Space Science Institute
2024
Millennium Institute of Astrophysics
2023
Pontificia Universidad Católica de Chile
2023
Flatiron Health (United States)
2017-2020
Flatiron Institute
2017-2020
Max Planck Society
2019
Abstract The Laser Interferometer Space Antenna (LISA) will be a transformative experiment for gravitational wave astronomy, and, as such, it offer unique opportunities to address many key astrophysical questions in completely novel way. synergy with ground-based and space-born instruments the electromagnetic domain, by enabling multi-messenger observations, add further discovery potential of LISA. next decade is crucial prepare community LISA’s first observations. This review outlines...
Massive black holes (BHs) inhabit local galaxies, including the Milky Way and some dwarf galaxies. BH formation, occurring at early cosmic times, must account for properties of BHs in today's notably why galaxies host a BH, others do not. We investigate distribution growth `seeds' by using adaptive mesh refinement code Ramses. develop an implementation formation dense, low-metallicity environments, as advocated models invoking collapse first generation stars, or dense nuclear star clusters....
Supermassive black hole feedback is thought to be responsible for the lack of star formation, or quiescence, in a significant fraction galaxies. We explore how observable correlations between specific formation rate (sSFR), stellar mass (M$_{\rm{star}}$), and (M$_{\rm{BH}}$) are sensitive physics galaxy model. use IllustrisTNG simulation suite, specifically TNG100 ten model variations that alter parameters Focusing on central galaxies at $z = 0$ with M$_{\rm{star}} > 10^{10}$ M$_{\odot}$, we...
ABSTRACT The past decade has seen significant progress in understanding galaxy formation and evolution using large-scale cosmological simulations. While these simulations produce galaxies overall good agreement with observations, they employ different sub-grid models for supermassive black holes (BHs). We investigate the impact of on BH mass properties Illustris, TNG100, TNG300, Horizon-AGN, EAGLE, SIMBA simulations, focusing MBH − M⋆ relation function. All predict tight relations, struggle...
We present the first results from JWST ASPIRE program (A SPectroscopic survey of biased halos In Reionization Era). This represents an imaging and spectroscopic 25 reionization-era quasars their environments by utilizing unprecedented capabilities NIRCam Wide Field Slitless Spectroscopy (WFSS) mode. will deliver largest ($\sim280~{\rm arcmin}^2$) galaxy redshift at 3-4 $\mu$m among Cycle-1 programs provide extensive legacy values for studying formation earliest supermassive black holes...
Abstract In less than two years of operation, the James Webb Space Telescope (JWST) has already accelerated significantly our quest to identify active massive black holes (BHs) in first billion Universe’s history. At time writing, about 50 AGN detections and candidates have been identified through spectroscopy, photometry, and/or morphology. Broad-line are a hundred times more numerous faint end UV-bright quasar population at z ∼ 5 − 6. this paper, we compare observational constraints on...
Using a suite of three large cosmological hydrodynamical simulations, horizon–AGN, horizon–noagn (no AGN feedback) and horizon–dm baryons), we investigate how typical sub-grid model for feedback affects the evolution inner density profiles massive dark matter haloes galaxies. Based on direct object-to-object comparisons, find that integrated mass slope differences between objects formed in these simulations (hereafter, HAGN, HnoAGN HDM) significantly evolve with time. More specifically, at...
Supermassive black holes (BHs) of millions solar masses and above reside in the center most local galaxies, but they also power active galactic nuclei quasars, detected up to z=7. This observational evidence puts strong constraints on BH growth mass first seeds. The scenario "direct collapse" is very appealing as it leads formation large seeds range 10^4-10^6 Msun, which eases explaining how quasars at z=6-7 are powered by BHs with >10^9 Msun. Direct collapse, however, appears be rare,...
ABSTRACT The James Webb Space Telescope will have the power to characterize high-redshift quasars at z ≥ 6 with an unprecedented depth and spatial resolution. While brightest such redshift (i.e. bolometric luminosity $L_{\rm bol}\geqslant 10^{46}\, \rm erg/s$) provide us key information on most extreme objects in Universe, measuring black hole (BH) mass Eddington ratios of fainter bol}= 10^{45}-10^{46}\, erg\,s^{ -1}$ opens a path understand build-up more normal BHs 6. In this paper, we show...
Studies of rest-frame optical emission in quasars at $z>6$ have historically been limited by the wavelengths accessible ground-based telescopes. The James Webb Space Telescope (JWST) now offers opportunity to probe this deep into reionization epoch. We report observations eight $z>6.5$ using JWST/NIRCam Wide Field Slitless Spectroscopy, as a part ''A SPectroscopic survey biased halos In Reionization Era (ASPIRE)" program. Our JWST spectra cover quasars' between rest frame $\sim$ 4100 and...
The Advanced X-ray Imaging Satellite (AXIS) is a Probe-class concept that will build on the legacy of Chandra Observatory by providing low-background, arcsecond-resolution imaging in 0.3-10 keV band across 450 arcminute$^2$ field view, with an order magnitude improvement sensitivity. AXIS utilizes breakthroughs construction lightweight segmented optics using single-crystal silicon, and developments fabrication large-format, small-pixel, high readout rate CCD detectors good spectral...
Abstract We present in this paper (Paper II of the series) a 35 arcmin 2 JWST/NIRCam imaging and wide-field slitless spectroscopy mosaic centered on J0305–3150, luminous quasar at z = 6.61. The F356W grism data reveal 124 [O iii ]+H β emitters 5.3 < 7, 53 which constitute protocluster spanning (10 cMpc) across 6.5 6.8. find no evidence any broad-line active galactic nucleus (AGN) individual galaxies or stacking, reporting median H FWHM 585 ± 152 km s −1 ; however, mass–excitation diagram...
We study the connection between active galactic nuclei (AGN) and their host galaxies through cosmic time in large-scale cosmological IllustrisTNG simulations. first compare BH properties, i.e. hard X-ray luminosity function, AGN galaxy occupation fraction, distribution of Eddington ratios, to available observational constraints. The simulations produce a population BHs good agreement with observations, but we note an excess faint (L_x ~ 10^{43-44} erg/s), lower number bright (L_x>10^{44}...
ABSTRACT In large-scale hydrodynamical cosmological simulations, the fate of massive galaxies is mainly dictated by modelling feedback from active galactic nuclei (AGNs). The amount energy released AGN proportional to mass that has been accreted on black holes (BHs), but exact subgrid differs in all simulations. While modern simulations reliably produce populations quiescent at z ≤ 2, it also crucial assess similarities and differences responsible populations. Here, we compare Illustris,...
Cosmic voids, the less dense patches of Universe, are promising laboratories to extract cosmological information. Thanks their unique low density character, voids extremely sensitive diffuse components such as neutrinos and dark energy, represent ideal environments study modifications gravity, where effects expected be more prominent. Robust void-related observables, including for example redshift-space distortions (RSD) weak lensing around a way chase test new physics. Cosmological analysis...
Recent systematic searches for massive black holes (BHs) in local dwarf galaxies led to the discovery of a population faint Active Galactic Nuclei (AGN). We investigate agreement BH and AGN populations Illustris, TNG, Horizon-AGN, EAGLE, SIMBA simulations with current observational constraints low-mass galaxies. find that some these produce BHs are too massive, occupation fraction at z=0 is not inherited from simulation seeding modeling. The ability their host power an depends on galaxy...
We present an analysis showcasing how the Advanced X-ray Imaging Satellite (AXIS), a proposed NASA Probe-class mission, will significantly increase our understanding of supermassive black holes undergoing mergers—from kpc to sub-pc scales. In particular, AXIS point spread function, field view, and effective area are expected result in (1) detection hundreds thousands new dual AGNs across redshift range 0<z<5 (2) blind searches for binary that exhibiting merger signatures their light...
The X-ray luminosity function (XLF) of active galactic nuclei (AGN) offers a robust tool to study the evolution and growth supermassive black-hole population over cosmic time. Owing limited area probed by surveys, optical surveys are routinely used probe accretion in high-redshift Universe z ≥ 3. However, may be incomplete because they strongly affected dust redenning. In this work we derive XLF its at high redshifts ( 3) using large sample AGN selected different fields with various areas...
Cosmic voids, the under-dense regions of cosmic web, are widely used to constrain cosmology. Voids contain few, isolated galaxies, presumably expected be less evolved and preserving memory pristine Universe. We use cosmological hydrodynamical simulation Horizon-AGN coupled void finder {\sc \texttt{VIDE}} investigate properties galaxies in voids at z=0. find that, closer centers, low-mass more common than their massive counterparts. At fixed dark matter halo mass, they have smaller stellar...
High-redshift quasars are believed to reside in highly biased regions of the Universe, where black hole (BH) growth is sustained by an enhanced number mergers and being at intersection filaments bringing fresh gas. This assumption should be supported enhancement counts galaxies field view quasars. While current observations quasar environments do not lead a consensus on possible excess galaxies, future missions JWST, WFIRST, Euclid will provide new insights environments, substantially...
The Laser Interferometer Space Antenna (LISA) will be a transformative experiment for gravitational wave astronomy, and, as such, it offer unique opportunities to address many key astrophysical questions in completely novel way. synergy with ground-based and space-born instruments the electromagnetic domain, by enabling multi-messenger observations, add further discovery potential of LISA. next decade is crucial prepare community LISA's first observations. This review outlines extensive...
The nature and origin of supermassive black holes (SMBHs) remain an open matter debate within the scientific community. While various theoretical scenarios have been proposed, each with specific observational signatures, lack sufficiently sensitive X-ray observations hinders progress tests. In this white paper, we present how AXIS will contribute to solving issue. With angular resolution 1.5″ on-axis minimal off-axis degradation, designed a deep survey capable reaching flux limits in [0.5–2]...