A5002740696- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Computational Physics and Python Applications
- Remote Sensing in Agriculture
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Advanced Measurement and Metrology Techniques
- Radio Astronomy Observations and Technology
- Advanced Materials and Mechanics
- Transportation Planning and Optimization
- Complex Network Analysis Techniques
- Theoretical and Computational Physics
- Geographic Information Systems Studies
- Advanced Image Processing Techniques
- Error Correcting Code Techniques
- Satellite Image Processing and Photogrammetry
- CCD and CMOS Imaging Sensors
- Scientific Research and Discoveries
- Inertial Sensor and Navigation
- Vehicle Routing Optimization Methods
- Remote Sensing and LiDAR Applications
Carnegie Mellon University
2014-2024
University College London
2020-2022
Fermi National Accelerator Laboratory
2017
The intrinsic alignment of galaxy shapes with the large-scale density field is a contaminant to weak lensing measurements, as well being an interesting signature formation and evolution (albeit one that difficult predict theoretically). Here we investigate relative orientations stars dark matter haloes subhaloes (central satellite) extracted from MassiveBlack-II simulation, state-of-the-art high-resolution hydrodynamical cosmological simulation which includes stellar active galactic nucleus...
The intrinsic alignment of galaxies with the large-scale density field is an important astrophysical contaminant in upcoming weak lensing surveys. We present detailed measurements galaxy alignments and associated ellipticity–direction (ED) projected shape (wg+) correlation functions for cosmological hydrodynamic MassiveBlack-II simulation. carefully assess effects on shapes, misalignment stellar component dark matter two-point statistics iterative weighted (by mass luminosity) definitions...
We compare the shapes and intrinsic alignments of galaxies in MassiveBlack-II (MBII) cosmological hydrodynamic simulation to those an identical dark matter-only (DMO) simulation. Understanding impact baryonic physics on galaxy should prove useful for creating mock catalogues based DMO simulations that mimic simulations. The matter subhaloes are typically rounder MBII, stellar low-mass more misaligned with corresponding At z = 0.06, fractional difference mean misalignment angle between MBII...
We study the shapes and intrinsic alignments of discs elliptical galaxies in MassiveBlack-II (MBII) Illustris cosmological hydrodynamic simulations, with volumes (100 h−1 Mpc)3 (75 Mpc)3, respectively. find that simulated disc are more oblate shape misaligned their host dark matter subhalo when compared ellipticals. The major axis is found to be oriented towards location nearby galaxies. also thinner MBII misalignments halo orientations smaller both ellipticals Illustris. As a result,...
SPHEREx is a proposed NASA MIDEX mission selected for Phase A study. would carry out the first all-sky spectral survey in near infrared. At end of its two-year mission, obtain 0.75-to-5$\mu$m spectra every 6.2 arcsec pixel on sky, with resolution R>35 and 5-$\sigma$ sensitivity AB$>$19 per spectral/spatial element. More details concerning are available at http://spherex.caltech.edu. The team has three specific science investigations to be carried this unique data set: cosmic inflation,...
Halos and galaxies acquire their angular momentum during the collapse of surrounding large-scale structure. This process imprints alignments between galaxy spins nearby filaments sheets. Low mass halos grow by accretion onto filaments, aligning with whereas high mergers along generating perpendicular to filament. We search for this alignment signal using identified "Cosmic Web Reconstruction" algorithm applied Sloan Digital Sky Survey Main Galaxy Sample from MaNGA integral-field unit survey....
ABSTRACT Using deep images from the Hyper Suprime-Cam (HSC) survey and taking advantage of its unprecedented weak lensing capabilities, we reveal a remarkably tight connection between stellar mass distribution massive central galaxies their host dark matter halo mass. Massive with more extended distributions tend to live in haloes. We explain this phenomenological model that assumes, (1) relation total content halo, (2) fraction situ ex at r <10 kpc depends on This provides an...
In the coming decade, a new generation of telescopes, including JWST and WFIRST, will probe period formation first galaxies quasars, open up last frontier for structure formation. Recent simulations as well observations have suggested that these are strongly clustered (with large scale bias $\gtrsim6$), therefore significant cosmic variance. this work, we use \texttt{BlueTides}, largest volume cosmological simulation galaxy formation, to directly estimate variance current upcoming surveys....
In this paper, we study the filamentary structures and galaxy alignment along filaments at redshift $z=0.06$ in MassiveBlack-II simulation, a state-of-the-art, high-resolution hydrodynamical cosmological simulation which includes stellar AGN feedback volume of (100 Mpc$/h$)$^3$. The are constructed using subspace constrained mean shift (SCMS; Ozertem & Erdogmus (2011) Chen et al. (2015a)). First, show that reconstructed galaxies dark matter particles similar to each other; over $50\%$ points...
Whether among the myriad tiny proto-galaxies there exists a population with similarities to present day galaxies is an open question. We show, using BlueTides, first hydrodynamic simulation large enough resolve relevant scales, that massive form are %in fact predicted have extensive rotationally-supported disks. Although their morphology resembles in some ways Milky-way types seen at much lower redshifts, these high-redshift smaller, denser, and richer gas than low redshift counterparts....
Supermassive blackholes with masses of a billion solar or more are known to exist up $z=7$. However, the present-day environments descendants first quasars is not well understood and it if they live in massive galaxy clusters isolated galaxies at $z=0$. We use dark matter-only realization (BTMassTracer) BlueTides cosmological hydrodynamic simulation study halo properties most black holes $z=8$. find that amongst halos. They reside halos group-like ($\sim 10^{14}M_{\odot}$) masses, while...
A strong correlation has been measured between the observed centripetal accelerations in galaxies and implied by baryonic components of galaxies. This empirical radial acceleration relation must be accounted for any viable model galaxy formation. We measure compare contributed baryons dark matter disk MassiveBlack-II hydrodynamic formation simulation. The sample 1594 spans three orders magnitude luminosity four surface brightness, comparable to from Spitzer Photometry & Accurate Rotation...
Many theoretical models predict that quasar-driven outflows account for the observed quenching of star formation in massive galaxies. There is growing observational evidence quasar-launched at z > 6, while details outflow–host galaxy interaction remain obscure. In this paper, we study feedback around highest redshift quasar BlueTides simulation, largest volume cosmological hydrodynamic simulation so far carried out. We present predictions gas brightest = 7.54 hosts most black hole volume,...
The use of high-quality simulated sky catalogs is essential for the success cosmological surveys. have diverse applications, such as investigating signatures fundamental physics in observables, understanding effect systematic uncertainties on measured signals and testing mitigation strategies reducing these uncertainties, aiding analysis pipeline development testing, survey strategy optimization. list applications growing with improvements quality details that they can provide. Given...
We investigate the redshift evolution of intrinsic alignments (IA) galaxies in \texttt{MassiveBlackII} (MBII) simulation. select galaxy samples above fixed subhalo mass cuts ($M_h>10^{11,12,13}~M_{\odot}/h$) at $z=0.6$ and trace their progenitors to $z=3$ along merger trees. Dark matter components are more spherical than while stellar tend be less progenitors. The distribution galaxy-subhalo misalignment angle peaks $\sim10~\mathrm{deg}$ with a mild increase time. ellipticity-direction~(ED)...
The most distant known quasar recently discovered by Ba\~nados et al. (2018) is at $z=7.5$ (690 Myr after the Big Bang), dawn of galaxy formation. We explore host brightest in large volume cosmological hydrodynamic simulation BlueTides, which Phase II has reached these redshifts. BlueTides a luminosity $\sim$ few $10^{13} L_{\odot}$ and black hole mass $6.4 \times 10^{8} M_{\odot}$ $z \sim 7.5$, comparable to observed (the only one this volume). resides rare halo $M_{H} 10^{12} stellar $4...
We study the alignments of satellite galaxies, and their anisotropic distribution, with respect to location orientation host central galaxy in MassiveBlack-II IllustrisTNG simulations. find that: shape system halos mass ($> 10^{13}h^{-1}M_{\odot}$) is well aligned at $z=0.06$ mean alignment between major axes being $\sim \Delta \theta = 12^{\circ}$ when compared a uniform random distribution; that galaxies tend be anisotropically distributed along axis stronger higher or luminosity;...
In this mini-review, we introduce and summarize research from the Quantum Technologies Group (QTG) at Carnegie Mellon University related to computational experience with quantum annealing, performed in collaboration several other institutions including IIT-Madras NASA (QuAIL). We present a novel hybrid quantum-classical heuristic algorithm (GAMA, Graver Augmented Multi-seed Algorithm) for non-linear, integer optimization, illustrate it on an application (in cancer genomics). then algebraic...
We explore the effects of specific assumptions in subgrid models star formation and stellar AGN feedback on intrinsic alignments galaxies cosmological simulations "MassiveBlack-II" family. Using smaller volume simulations, we explored parameter space model found remarkable robustness observable statistical measures to details physics. The one observational probe most sensitive modeling is distribution misalignment angles. hypothesize that amount angular momentum carried away by galactic wind...
We use the IllustrisTNG suite of cosmological simulations to measure intrinsic alignment (IA) bispectra dark matter subhalos between redshifts 0 and 1. decompose shear field into E- B-modes find that $B_{\delta\delta\mathrm{E}}$ $B_{\delta\mathrm{EE}}$, overdensity field, $\delta$, E-mode are detected with high significance. also model IA analytically using a method consistent two-point non-linear model. this simulation measurements infer amplitude $A_\mathrm{IA}$ values obtained from power...
In the aftermath of a sudden catastrophe, First Responders (FR) strive to promptly reach and rescue immobile victims. Simultaneously, other mobile individuals take roads evacuate affected region, or access shelters. The escalated traffic congestion significantly hinders critical FR operations if they share some same roads. A proposal from Turkish Ministry Transportation Infrastructure being discussed for implementation is allocate subset road segments use by FRs only, mark them clearly,...
In the aftermath of a sudden catastrophe, first responders (FRs) strive to reach and rescue immobile victims. Simultaneously, civilians use same roads evacuate, access medical facilities shelters, or reunite with their relatives via private vehicles. The escalated traffic congestion can significantly hinder critical FR operations. A proposal from Türkiye Ministry Transportation Infrastructure is allocate lane on specific road segments exclusively for use, mark them clearly, precommunicate...
The software in this repository is developed to solve the First Responder Network Design Problem (FRNDP) using Graver Augmentation Multi-seeded Algorithm (GAMA) and Branch-and-Bound.
ABSTRACT The Nancy Grace Roman Space Telescope (RST), with its field of view and high sensitivity will make surveys cosmological large-scale structure possible at redshifts. We investigate the possibility detecting baryon acoustic oscillations (BAO) redshifts z > 7.6 for use as a standard ruler. data from hydrodynamic simulation bluetides in conjunction gigaparsec-scale Outer Rim model patchy reionization to create mock RST High Latitude Survey grism Lyman α emission line selected...