A5015918737- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- History and Developments in Astronomy
- Chronic Obstructive Pulmonary Disease (COPD) Research
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Respiratory and Cough-Related Research
- Astrophysics and Star Formation Studies
- Healthcare Systems and Practices
- Respiratory Support and Mechanisms
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
University of Surrey
2016-2021
Centre National de la Recherche Scientifique
2020-2021
Institut de Recherche sur les Lois Fondamentales de l'Univers
2020-2021
CEA Paris-Saclay
2020-2021
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2020-2021
Université Paris-Saclay
2020-2021
Astrophysique, Instrumentation et Modélisation
2020-2021
Université Paris Cité
2020-2021
Université de Versailles Saint-Quentin-en-Yvelines
2021
ABSTRACT In the standard Lambda cold dark matter paradigm, pure simulations predict dwarf galaxies should inhabit haloes with a centrally diverging density ‘cusp’. This is in conflict observations that typically favour constant ‘core’. We investigate this ‘cusp-core problem’ ‘ultra-faint’ simulated as part of ‘Engineering Dwarfs at Galaxy formation’s Edge’ project. find, similarly to previous work, gravitational potential fluctuations within central region dwarfs kinematically heat...
We present a new technique to probe the central dark matter (DM) density profile of galaxies that harnesses both survival and observed properties star clusters. As first application, we apply our method `ultra-faint' dwarf Eridanus II (Eri II) has lone cluster ~45 pc from its centre. Using grid collisional $N$-body simulations, incorporating effects stellar evolution, external tides dynamical friction, show DM core for Eri naturally reproduces size projected position cluster. By contrast,...
ABSTRACT Massive elliptical galaxies are typically observed to have central cores in their projected radial light profiles. Such long been thought form through ‘binary scouring’ as supermassive black holes (SMBHs), brought mergers, a hard binary and eject stars from the galactic centre. However, most massive cores, like $\sim 3{\, \mathrm{kpc}}$ core A2261-BCG, remain challenging explain this way. In paper, we run suite of dry galaxy merger simulations explore three different scenarios for...
The coalescence of massive black hole binaries (BHBs) in galactic mergers is the primary source gravitational waves (GWs) at low frequencies. Current estimates GW detection rates for Laser Interferometer Space Antenna and Pulsar Timing Array vary by three orders magnitude. To understand this variation, we simulate merger equal-mass, eccentric, galaxy pairs with central holes shallow inner density cusps. We model formation hardening a BHB using Fast Multiple Method as force solver, which...
We present a novel positive potential-density pair expansion for modelling galaxies, based on the Miyamoto–Nagai disc. By using three sets of such discs, each one them aligned along symmetry axis, we are able to reconstruct broad range potentials that correspond density profiles from exponential discs 3D power-law models with varying triaxiality (henceforth simply ‘twisted’ models). increase efficiency our by allowing scalelength parameter disc be negative. show that, suitable priors and...
We present new chemo--kinematics of the Hercules dwarf galaxy based on Keck II-- DEIMOS spectroscopy. Our 21 confirmed members have a systemic velocity $v_{\mathrm{Herc}}=46.4\pm1.3$ kms$^{-1}$ and dispersion $\sigma_{v,\mathrm{Herc}}=4.4^{+1.4}_{-1.2}$ kms$^{-1}$. From strength Ca II triplet, we obtain metallicity [Fe/H]= $-2.48\pm0.19$ dex $\sigma_{\rm{[Fe/H]}}= 0.63^{+0.18}_{-0.13}$ dex. This makes particularly metal--poor galaxy, placing it slightly below standard mass--metallicity...
Abstract We present results of our dynamical stream modelling for the North West Stream in outer halo Andromeda galaxy (M31). Comprising two main segments, was thought to be a single structured arching around M31. However, recent evidence suggests that it is separate, unrelated, streams. To test this hypothesis we use observational data from 6 fields associated with upper segment together 8 and 5 globular clusters lower constrain model orbits. fit both segments using fixed potential M31 an...
We present results of our dynamical stream modelling for the North West Stream in outer halo Andromeda galaxy (M31). Comprising two main segments, was thought to be a single structured arching around M31. However, recent evidence suggests that it is separate, unrelated, streams. To test this hypothesis we use observational data from 6 fields associated with upper segment together 8 and 5 globular clusters lower constrain model orbits. fit both segments using fixed potential M31 an orbit...
We present a kinematic and spectroscopic analysis of 38 red giant branch stars, in 7 fields, spanning the dwarf spheroidal galaxy Andromeda XXVII upper segment North West Stream. Both features are located outer halo at projected radius 50-80 kpc, with stream extending for $\sim$3$^{\circ}$ on sky. Our data is obtained as part PAndAS survey enables us to confirm that XXVII's heliocentric distance 827 $\pm$ 47 kpc metallicity -2.1$^{+0.4}_{-0.5}$. also re-derive properties, measuring systemic...