Hawaii Two-0 Observing Plan
2018A — NEP
- 4 nights HSC (4 nights lost to earthquakes)
2018B — CDF-S
- 5 nights HSC (3 nights lost to earthquakes, 2 successful nights)
2019A — NEP
- 4 nights HSC (observations TBD)
2019B — CDF-S
- 4 nights HSC
- 3 nights DEIMOS
- Proposal under IfA TAC review
2020A — CDF-S + NEP
- 5 nights HSC
- 2 nights DEIMOS
- 2 nights MOSFIRE
2020B — CDF-S + NEP
- 5 nights Subaru HSC
- 2 nights Keck MOSFIRE
- The HSC Data Reduction Pipeline has been successfully installed and tested on the UH Cray supercomputer
- Co-I Chambers will ensure the team has access to the latest Pan-STARRS data for astrometric and flux calibration.
- Generation of HSC mosaic will be done by Co-Is Repp & McPartland
- The IRAC image mosaic pipeline of Co-I Capak has recently been optimized for cluster/supercomputer environments. The runtime of the pipeline analysis is now only a few hours, rather than a few weeks with the original version.
- IRAC photometry will be measured using IRClean (Co-I Capak lead) that was successfully applied in COSMOS and SPLASH Laigle et al. (2016).
Extraction of Data from the Archives
- We have discovered a significant amount of HSC data in the Subaru archive covering the two H20 fields:
- NEP: HEROES and AKARI-NEP programs (~50% of total data needed)
- CDF-S: various small programs (~10% of total data needed)
- With these data in hand, we have nearly made up for the HSC time lost in 2018. See Archival Data on the Progress Page for more details.
- Initial reduction of archival NEP & CDF-S data
- Dropout selection using COSMOS data
- Preliminary measurements of the two-point correlation function & galaxy-dark matter bias.
Purchase of Data Storage/Reduction Server
- We have recently purchased a dedicated server for H20 data storage and reduction. This will allow us to streamline the data reduction process by minimizing latency due to data transfer.
- 60+ TB hard drive, 24 CPU cores, 512 Gb RAM
Hawaii Two-0 Survey Footprint
The 10 deg footprint for each of the H20 fields comprised of seven HSC pointings arranged in a flower petal pattern.
*** Note: We will continue to request classical time until Subaru can develop a more robust and widely used queue system. Furthermore, due to the RA/elevation constraints of our fields, it is much more efficient to execute the observations in classical mode. ***
Limiting Magnitudes / Exposure Times for Final Survey
|HSC exposure time||1.1h||2.5h||4.1h||4.8h||9h||—||—||—|
☆ From Euclid Deep (operations start in 2021). WFIRST will also cover this area at 26 mag 10σ (operations start mid-2020s).
† From the Euclid/WFIRST Spitzer Legacy Survey (ADS)
High-z Dropout Selection
To confirm the ability of the Hawaii Two-0 (20 sq. deg.) survey (as designed) to robustly identify high-redshift galaxies (z≳4) using our H20 dropout selection technique, we used the UH+SSP HSC data in the COSMOS (2 sq. deg.) field to select high redshift galaxy candidates. See Dropout Selection Section of the Science Page for more details.
|Dropout Band||Redshift||Expected Sources in
H20 20 sq. deg
Photo-z selected sources
|Redshift||Expected Sources in
H20 20 sq. deg
Note that r-band dropouts are sources that “just begin to appear” in the r-band, are clearly absent in the g-band, and robustly detected in the i-band. The above figure clearly illustrates the potential for H20 observations to detect high-redshift dropout galaxies.
Exposure Time Calculations for
***High level summary***
Density of High-Redshift Dropout Targets in a DEIMOS FOV
In each DEIMOS mask (16’x4′, yellow box), we expect to collect spectra for:
60+ g-band droupouts
40 r-band droupouts
10 i-band droupouts
For comparison, we indicate the smaller LRIS FOV (6’x7.8′, red dashed box).
Expected Magnitude Distributions for the gri-band Dropouts
DEIMOS Instrument Configuration & Exposure Times
The optimal configuration for our DEIMOS spectroscopy is the 600ZD grating with the OG550 order blocking filter (green dot-dashed line below). This configuration maximizes efficiency over the wavelength range where we expect to dectect Ly-α emission in the gri-band dropout galaxies at z = 4, 5, & 6. The galaxy templates were generated using FSPS assuming a 10^10 Msun galaxy with a delayed-exponential SFH with τ = 2 Gyr and age of 1 Gyr. The signal to noise estimates are based on an exposure time of 3.5hrs with a 1 arcsec slit, 1 arcsec seeing, and an airmass of 1.3.