0 Assigned ID: 1863 ----- Attempting Submission 1 (Fri Apr 09 09:39:06 GMT 2021) ----- HST Phase I Proposal 1863 successfully submitted. Receipt: # 1863-1 ----- Attempting Submission 2 (Fri Apr 09 20:58:59 GMT 2021) ----- HST Phase I Proposal 1863 successfully submitted. Receipt: # 1863-2 ----- Attempting Submission 3 (Fri Apr 09 23:18:37 GMT 2021) ----- HST Phase I Proposal 1863 successfully submitted. Receipt: # 1863-3 ----- Attempting Submission 4 (Fri Apr 09 23:57:58 GMT 2021) ----- HST Phase I Proposal 1863 successfully submitted. Receipt: # 1863-4 ----- Attempting Submission 5 (Fri Apr 09 23:59:29 GMT 2021) ----- HST Phase I Proposal 1863 successfully submitted. Receipt: # 1863-5 ----- Attempting Submission 6 (Sat Apr 10 00:02:33 GMT 2021) ----- HST Phase I Proposal 1863 successfully submitted. Receipt: # 1863-6 ----- Attempting Submission 7 (Sat Apr 10 00:04:58 GMT 2021) ----- HST Phase I Proposal 1863 successfully submitted. Receipt: # 1863-7 ----- Attempting Submission 8 (Sat Apr 10 00:07:05 GMT 2021) ----- The intensity of the near-IR extragalactic background light (EBL) is a useful measurement as astronomers strive to identify a complete census of all extragalactic objects. Significantly, direct measurements of the EBL generally arrive at intensities beyond that expected by integrated object counts from deep surveys. As these measurements have significant uncertainties, with different techniques arriving at different results, improved direct measurements of the EBL using HST have potential the potential to resolve this discrepancy and inform our understanding of the origin of any diffuse component. However, uncertainties in the level of the thermal emission contributing to HST's background substantially limit HST's ability to constrain the EBL in the near-IR. Because thermal emission is a substantial component of the background in the near-IR, the ~20% uncertainty in the level of the thermal foreground translates to a ~30% uncertainty in the EBL level in F125W and a nearly 100% uncertainty in the EBL in F160W. We propose an archival analysis of a large number of HST's near-IR observations to constrain the thermal foreground signal as a function of orbital parameters to better than 5%, allowing measurements of the EBL using HST to achieve a similar uncertainty. This analysis will be able to: (1) Improve constraints on the level of diffuse EBL. (2) Allow for more precise sky subtraction for large objects. (3) Improve HST observation planning and data reduction. Overall, the improved understanding of HST's background possible with this analysis has exceptional scientific and legacy value. This team has the expertise required to successfully conduct the proposed analysis. Dr. Carleton has experience working with near-IR data and modeling its various components. His research focuses on comparing models and observations. Prof. Windhorst has over 30 years of experience working on and with HST. Prof. Windhorst is the PI of the SKYSURF project to measure the EBL using HST. Sarah Caddy is a PhD candidate focusing on the detection and modelling of bright foreground emissions in order to constrain the EBL. She is currently working with the SKYSURF team to constrain the uncertainty on the detected EBL due to Zodiacal Light emissions and reduce Earthshine contamination. Her Masters work involved detecting and modelling Earthshine in HST imaging data from satellite weather data. She also has experience in the construction of Bayesian inference models for optical systems in order to constrain systematic errors for the measurement of the EBL. Dr. Seth Cohen has over 20 years of experience working with and analyzing HST data. Dr. Rolf Jansen has over 20 years of experience working with HST data and has experience analyzing sky measurements using HST. Large Scale Structure of the Universe Galaxies 0 Regular true false false false false SUPPORTED