A5014522902- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Computational Physics and Python Applications
- Adaptive optics and wavefront sensing
- Dark Matter and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Plant Water Relations and Carbon Dynamics
- Solar and Space Plasma Dynamics
- CCD and CMOS Imaging Sensors
- Pulsars and Gravitational Waves Research
- Impact of Light on Environment and Health
- Superconducting and THz Device Technology
- Calibration and Measurement Techniques
- Astro and Planetary Science
- Spectroscopy and Laser Applications
- History and Developments in Astronomy
Royal Observatory
2017-2025
University of Edinburgh
2017-2025
University of the Western Cape
2016-2025
Scottish Universities Physics Alliance
2019-2024
UK Astronomy Technology Centre
2018-2024
South African Radio Astronomy Observatory
2015-2024
ORCID
2020-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2024
Stellenbosch University
2024
Universidad Autónoma de Madrid
2023
We examine the temperature history of gas accreted by forming galaxies in SPH simulations. About half shock heats to roughly virial galaxy potential well before cooling, condensing, and stars, but other radiates its acquired gravitational energy at much lower temperatures, typically T<10^5 K, histogram maximum temperatures is clearly bimodal. The "cold mode" accretion dominates for low mass (M_baryon < 10^{10.3}Msun or M_halo 10^{11.4}Msun), while conventional "hot growth high systems....
The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over approximate redshift (z) range 8--1.5. It will image >250,000 distant galaxies using three separate cameras on Hubble Space Telescope, from mid-ultraviolet near-infrared, and find measure Type Ia supernovae at z>1.5 test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with...
This paper describes the Hubble Space Telescope imaging data products and reduction procedures for Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). survey is designed to document evolution of galaxies black holes at $z\sim1.5-8$, study Type Ia SNe beyond $z>1.5$. Five premier multi-wavelength sky regions are selected, each with extensive multiwavelength observations. The primary CANDELS consist obtained in Wide Field Camera 3 / infrared channel (WFC3/IR) UVIS channel,...
We introduce the simba simulations, next generation of mufasa cosmological galaxy formation simulations run with gizmo's meshless finite mass hydrodynamics. includes updates to mufasa's sub-resolution star and feedback prescriptions, introduces black hole growth via torque-limited accretion model Anglés-Alcázar et al. from cold gas Bondi hot gas, along kinetic bipolar outflows X-ray energy. Ejection velocities are taken be |${\sim } 10^3\,\,{\rm km}\, {\rm s}^{-1}$| at high Eddington ratios,...
The halo occupation distribution (HOD) describes the relation between galaxies and dark matter at level of individual halos. properties residing centers halos differ from those satellite because differences in their formation histories. Using a smoothed particle hydrodynamics (SPH) simulation semi-analytic (SA) galaxy model, we examine separate contributions central to HOD, more specifically probability P(N|M) that virial mass M contains N particular class. In agreement with earlier results...
We study the formation of galaxies in a large volume (50 h−1 Mpc, 2 × 2883 particles) cosmological simulation, evolved using entropy and energy-conserving smoothed particle hydrodynamics (SPH) code gadget-2. Most baryonic mass all masses is originally acquired through filamentary 'cold mode' accretion gas that was never shock heated to its halo virial temperature, confirming key feature our earlier results obtained with different SPH code. Atmospheres hot, virialized develop haloes above 2–3...
Modeling galaxy formation in a cosmological context presents one of the greatest challenges astrophysics today due to vast range scales and numerous physical processes involved. Here we review current status models that employ two leading techniques simulate physics formation: semianalytic numerical hydrodynamic simulations. We focus on set observational targets describe evolution global structural properties galaxies from roughly cosmic high noon (z ∼ 2–3) present. Although minor...
Approximately 30-40% of all baryons in the present day universe reside a warm-hot intergalactic medium (WHIM), with temperatures between 10^5<T<10^7 K. This is generic prediction from six hydrodynamic simulations currently favored structure formation models having wide variety numerical methods, input physics, volumes, and spatial resolutions. Most these diffuse large-scale structures median overdensity around 10-30, not virialized objects such as galaxy groups or galactic halos. The...
We investigate models of self-consistent chemical enrichment the intergalactic medium (IGM) from z=6 to 1.5, based on hydrodynamic simulations structure formation that incorporate galactic outflows. Our main result is outflow parameterizations momentum-driven winds as seen in local starburst galaxies provide best agreement with observations CIV absorption at z~2-5. Such sufficiently enrich high-z IGM produce a global mass density absorbers relatively invariant z=5.5 observations. This occurs...
We analyze the physical conditions of cool, photoionized (T $\sim 10^4$ K) circumgalactic medium (CGM) using COS-Halos suite gas column density measurements for 44 gaseous halos within 160 kpc $L \sim L^*$ galaxies at $z 0.2$. These data are well described by simple photoionization models, with highly ionized (n$_{\rm HII}$/n$_{\rm H} \gtrsim 99\%$) extragalactic ultraviolet background (EUVB). Scaling estimates virial radius, R$_{\rm vir}$, we show that ionization state (tracked...
We present Bayesian Analysis of Galaxies for Physical Inference and Parameter EStimation, or BAGPIPES, a new Python tool which can be used to rapidly generate complex model galaxy spectra fit these arbitrary combinations spectroscopic photometric data using the MultiNest nested sampling algorithm. extensively test our ability recover realistic star-formation histories (SFHs) by fitting mock observations quiescent galaxies from MUFASA simulation. then perform detailed analysis SFHs sample...
The circumgalactic medium (CGM) is fed by galaxy outflows and accretion of intergalactic gas, but its mass, heavy element enrichment, relation to properties are poorly constrained observations. In a survey the outskirts 42 galaxies with Cosmic Origins Spectrograph onboard Hubble Space Telescope, we detected ubiquitous, large (150 kiloparsec) halos ionized oxygen surrounding star-forming galaxies, find much less around little or no star formation. This CGM contains substantial mass elements...
We present an analytic formalism that describes the evolution of stellar, gas and metal content galaxies. It is based on idea, inspired by hydrodynamic simulations, galaxies live in a slowly evolving equilibrium between inflow, outflow star formation. argue this broadly captures behaviour galaxy properties simulations. The resulting equations for formation rate, fraction metallicity depend three key free parameters represent ejective feedback, preventive feedback reaccretion ejected...
Using Gadget-2 cosmological hydrodynamic simulations including an observationally-constrained model for galactic outflows, we investigate how feedback from star formation distributes mass, metals, and energy on cosmic scales z=6->0. We include instantaneous enrichment Type II SNe, delayed Ia SNe stellar (AGB) mass loss, individually track C, O, Si, Fe. Following the successes of momentum-driven wind scalings, improve our implementation with on-the-fly galaxy finder to derive properties...
We study the physical origin of low-redshift Lyman alpha forest in hydrodynamic simulations four CDM cosmologies. Our main conclusions are insensitive to cosmological model but depend on our assumption that UV background declines at low redshift. find expansion universe drives rapid evolution dN/dz (the number absorbers per unit z) z > 1.7, lower redshift fading counters influence expansion, leading slow evolution. At every redshift, weaker lines come primarily from moderate fluctuations...
(Abridged) Using cosmological hydrodynamic simulations in combination with analytic modeling, we show that the galaxy stellar mass-metallicity relation (MZR) provides strong constraints on galactic outflows across cosmic time. We compare three outflow models: No outflows, a "constant wind" (cw) model emulates popular Dekel & Silk (1986) scenario, and ``momentum-driven (vzw) model. find only vzw scaling reproduces observed z~2 MZR's slope, amplitude, scatter. Comparing our fully...
In this paper we present the MOSFIRE Deep Evolution Field (MOSDEF) survey. The MOSDEF survey aims to obtain moderate-resolution (R=3000-3650) rest-frame optical spectra (~3700-7000 Angstrom) for ~1500 galaxies at 1.37<z<3.80 in three well-studied CANDELS fields: AEGIS, COSMOS, and GOODS-N. Targets are selected redshift intervals: 1.37<z<1.70, 2.09<z<2.61, 2.95<z<3.80, down fixed H_AB (F160W) magnitudes of 24.0, 24.5 25.0, respectively, using photometric spectroscopic catalogs from 3D-HST We...
We use the chemical evolution predictions of cosmological hydrodynamic simulations with our latest theoretical stellar population synthesis, photoionization, and shock models to predict strong line ensembles galaxies from z = 3 present day. In this paper, we focus on brightest optical emission-line ratios, [N ii]/Hα [O iii]/Hβ. diagnostic Baldwin–Phillips–Terlevich (BPT) diagram as a tool for investigating spectral properties active galaxies. four redshift windows chosen exploit new...
We use cosmological hydrodynamic simulations to investigate how inflows, star formation, and outflows govern the gaseous metal content of galaxies. In our simulations, galaxy metallicities are established by a balance between inflows as governed mass outflow rate, implying that mass-metallicity relation reflects rate varies with stellar (M*). Gas is set competition inflow into gas consumption within ISM, latter being SF law, while former impacted both wind recycling preventive feedback....
We analyse cosmological hydrodynamic simulations that include observationally-constrained prescriptions for galactic outflows. If these simulated winds accurately represent in the real Universe, then material previously ejected provides dominant source of gas infall new star formation at redshifts z<1. This recycled wind accretion, or mode, a third physically distinct accretion channel addition to "hot" and "cold" modes emphasised recent theoretical studies. Because interaction between...
We present the design and methods of COS-Halos survey, a systematic investigation gaseous halos 44 z = 0.15-0.35 galaxies using background QSOs observed with Cosmic Origins Spectrograph aboard Hubble Space Telescope. This survey has yielded 39 spectra z_em ~ 0.5 S/N 10-15 per resolution element. The QSO sightlines pass within 150 physical kpc galaxies, which span early late types over stellar mass log M* / Msun= 9.5 - 11.5. find that CGM exhibits strong HI, averaging 1 Ang in Lya equivalent...
We examine the growth of stellar content galaxies from z=3-0 in cosmological hydrodynamic simulations incorporating parameterised galactic outflows. Without outflows, overproduce masses (M*) and star formation rates (SFRs) compared to observations. Winds introduce a three-tier form for galaxy mass rate functions, where middle tier depends on differential (i.e. mass-dependent) recycling ejected wind material back into galaxies. A tight M*-SFR relation is generic outcome all these simulations,...
Abstract We present an investigation into the first 500 Myr of galaxy evolution from Cosmic Evolution Early Release Science (CEERS) survey. CEERS, one 13 JWST ERS programs, targets formation z ∼ 0.5 to >10 using several imaging and spectroscopic modes. make use epoch CEERS NIRCam imaging, spanning 35.5 arcmin 2 , search for candidate galaxies at > 9. Following a detailed data reduction process implementing custom steps produce high-quality reduced images, we perform multiband...
We present the extended GALEX Arecibo SDSS Survey (xGASS), a gas fraction-limited census of atomic (HI) content 1179 galaxies selected only by stellar mass ($M_\star =10^{9}-10^{11.5} M_\odot$) and redshift ($0.01<z<0.05$). This includes new observations 208 galaxies, for which we release catalogs HI spectra. In addition to extending GASS scaling relations one decade in mass, quantify total (atomic+molecular) cold fractions molecular-to-atomic ratios, $R_{mol}$, subset 477 observed with IRAM...
We present the mufasa suite of cosmological hydrodynamic simulations, which employs gizmo meshless finite mass (MFM) code including H2-based star formation, nine-element chemical evolution, two-phase kinetic outflows following scalings from Feedback in Realistic Environments zoom and evolving halo mass-based quenching. Our fiducial (50 h−1 Mpc)3 volume is evolved to z = 0 with a quarter billion elements. The predicted galaxy stellar functions (GSMFs) reproduces observations 4 → ≲ 1.2σ cosmic...