Year: 2023
Type: article
Abstract: ABSTRACT Lyman α emitters (LAEs) are excellent probes of the reionization process, as they must be surrounded by large ionized bubbles in order to be visible during the reionization era. Large ionized regions are thought to correspond to overdense regions and may be protoclusters, making them interesting test-beds for early massive structures. Close associations containing several LAEs are often assumed to mark overdense, ionized bubbles. Here, we develop the first framework to quantify the ionization and density fields of high-z galaxy associations. We explore the interplay between (i) the large-scale density of a survey field, (ii) Poisson noise due to the small number density of bright sources at high redshifts (z ∼ 7), and (iii) the effects of the ionized fraction on the observation of LAEs. We use Bayesian statistics, a simple model of reionization, and a Monte Carlo simulation to construct a more comprehensive method for calculating the large-scale density of LAE regions than previous works. We find that Poisson noise has a strong effect on the inferred density of a region and show how the ionized fraction can be inferred. We then apply our framework to the strongest association yet identified: Hu et al. found 14 LAEs in a volume of ∼50 000 cMpc3 inside the COSMOS field at z ∼ 7. We show that this is most likely a 2.4σ overdensity inside of an ionized or nearly ionized bubble. We also show that this LAE association implies that the global ionized fraction is $\bar{Q} = 0.59^{+0.10}_{-0.11}$, within the context of a simple reionization model.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G2102378290, MULTIPLE YEAR AWARD WITH INCREMENTAL FUNDING FOR YEARS ONE TO FIVE. THIS PROPOSAL IS ENTITLED "NETWORK FOR EXPLORATION AND SPACE SCIENCE NESS." THIS IS AWARDED IN RESPONSE TO COOPERATIVE AGREEMENT NOTICE CAN NO. NNH16ZDA009C NASA SOLAR SYSTEM EXPLORATION RESEARCH VIRTUAL INSTITUTE SSERVI CYCLE THREE. THE PRINCIPAL INVESTIGATOR IS DR. JACK O. BURNS WITH THE UNIVERSITY OF COLORADO UCO. PROJECT SUMMARY: NESS WILL IMPLEMENT CROSS-DISCIPLINARY PARTNERSHIPS TO ADVANCE SCIENTIFIC DISCOVERY AND HUMAN EXPLORATION OF TARGET DESTINATIONS AND WILL CONDUCT RESEARCH IN ASTROPHYSICS AND HELIOPHYSICS THAT IS UNIQUELY ENABLED BY HUMAN AND ROBOTIC EXPLORATION OF TARGET BODIES. OUR RESEARCH IS DERIVED FROM THREE DECADAL SURVEYS AND FROM THE NASA ASTROPHYSICS AND GLOBAL EXPLORATION ROADMAPS. NESS RESEARCH INCLUDES: TELEROBOTIC OPERATION OF SURFACE SCIENCE EXPLORATION ASSETS AT THE MOON AND MARS THE NATURE OF THE MOON'S CORE AN IMPROVED SELENODETIC COORDINATE SYSTEM PRECISION TESTS OF GRAVITATION ENERGETIC SOLAR PARTICLE EVENTS IN INTERPLANETARY SPACE AND EXTRASOLAR SYSTEMS DUST ENVIRONMENTS OF SPACE AND TARGET BODIES DETECTION OF THE UNIVERSE'S FIRST GALAXIES AND HABITABLE EXOPLANETS. FOUR KEY PROJECTS WILL BE PROPOSED. EXPLORATION SCIENCE NESS WILL MATURE A CRITICAL TECHNOLOGY OF SCIENCE AND EXPLORATION MISSIONS FROM THE ORBITS OF TARGET BODIES: SURFACE TELEROBOTICS. WE WILL DEVELOP HUMAN-ROBOTIC SCIENCE ASSOCIATED WITH ORION/HABITAT MISSIONS IN CIS-LUNAR ORBITS. OUR TEAM WILL BUILD TOOLS FOR THE CREW TO TELEOPERATE ROVERS ON THE LUNAR FARSIDE THAT WILL FEED-FORWARD TO THE FIRST CREWED MARS MISSIONS. WE WILL INVESTIGATE THE SYSTEMS NEEDED ON ORION/HABITAT TO SUPPORT TELEROBOTICS ANALYZE LUNAR LOW FREQUENCY RADIO TELESCOPE DEPLOYMENT ALONG WITH A LUNAR SAMPLE RETURN AND DEVELOP CREW TRAINING STRATEGIES. LLR CURRENT ALTERNATE THEORIES OF GRAVITY PREDICT DEVIATIONS FROM GENERAL RELATIVITY GR AT A LEVEL THAT IS WITHIN THE GRASP OF THE NEXT GENERATION OF LUNAR LASER RANGING LLR INSTRUMENTS. NESS WILL IMPROVE BY FACTORS GREATER THAN 100 THE SIGNAL PHOTOELECTRON ACCURACY OF LLR TO SET NEW CONSTRAINTS ON GR AND THE LUNAR CORE. WE WILL ALSO MEASURE/MODEL DUST ON LLR OPTICAL SURFACES AND SIGNIFICANTLY IMPROVE THE SELENODETIC COORDINATE SYSTEM FOR EXPLORATION AND SCIENCE MISSIONS. HELIOPHYSICS AND SPACE PHYSICS_NESS HELIOPHYSICS RESEARCH DIRECTLY IMPACTS HUMAN EXPLORATION VIA OUR STUDIES OF SOLAR PARTICLE RADIATION AND INTERPLANETARY DUST. WE WILL ADVANCE THE DESIGN FOR A LUNAR-BASED LOW FREQUENCY LESS THAN 10 MHZ RADIO IMAGER UNIQUELY CAPABLE OF IMAGING THE TRAJECTORY OF PARTICLE ACCELERATION IN SOLAR ERUPTIONS AND MEASURING INTERPLANETARY NANODUST. FROM COSMIC DAWN TO HABITABLE PLANETS NESS ADDRESSES KEY QUESTIONS FROM THE ASTROPHYSICS DECADAL SURVEY: "WHEN AND HOW DID THE FIRST GALAXIES FORM?" AND "CAN WE FIND ANOTHER PLANET LIKE EARTH ORBITING A NEARBY STAR?" OUR TEAM WILL USE NEW MODELING TOOLS AND TECHNOLOGIES TO INVESTIGATE THE FORMATION OF THE FIRST GALAXIES USING THE NEUTRAL HYDROGEN 21-CM SIGNAL RED-SHIFTED TO 2-3 M. THE MOON'S FARSIDE IS UNIQUELY SHIELDED FROM RADIO FREQUENCY INTERFERENCE AND FREE FROM IONOSPHERIC EFFECTS TO ENABLE SUCH OBSERVATIONS. A FARSIDE OBSERVATORY IS IMPORTANT FOR EXPLORATION TO INVESTIGATE THE ENVIRONMENTAL AND TECHNICAL CHALLENGES TO DEPLOYING/OPERATING A LARGE-AREA SCIENTIFIC STATION ON THE MOON. WE WILL ADVANCE 21-CM COSMOLOGY THEORY THE DESIGN OF A LOW RADIO FREQUENCY ARRAY WIDE-BAND RECEIVERS AND NEW CALIBRATION TECHNIQUES. NESS ALSO WILL ADVANCE THE STUDY OF THE CHARACTERISTICS OF THE HABITABLE EXOPLANETS BY EMPLOYING POLARIMETRY ON LARGE UV_OPTICAL TELESCOPES CONSTRUCTED IN CIS-LUNAR SPACE AND BY USING A FARSIDE RADIO ARRAY TO DETECT MAGNETOSPHERES FOR EARTH-LIKE PLANETS., New Models of the Cosmic Dawn, Collaborative Research: Exploring reionization and the cosmic dawn through cross-correlations, G5195243372, G707938032, G8626377472
OpenAlex ID: W4385280308