Mission Overview
Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO)
Primary Investigator: Charles Steinhardt, Mathilde Jauzac
HLSP Authors: Anton M. Koekemoer, Amanda Pagul, Anna Niemiec
Released: 2023-08-01
Updated: 2023-08-01
Primary Reference(s): Steinhardt et al. 2020, Niemiec et al. 2023, Pagul et al. 2023
Citations: See ADS Statistics
Source Data: HST Proposal 15117
Slideshow
Full-color image of the first cluster observed by BUFFALO, Abell 370, in the full range of filters used for this program (ACS/WFC F606W and F814W, and WFC3/IR F105W, F125W, and F160W). The BUFFALO project overview is presented in Steinhardt et al. (2020), the full combined HST mosaics for all 6 clusters were produced following the approaches described in Koekemoer et al. (2011), the multi-wavelength photometric catalogs for all 6 clusters are presented in Pagul et al. (2023), and the the full lensing models for Abell 370 are presented in Niemiec et al. (2023).
Overview
The Beyond Ultra-deep Frontier Fields and Legacy Observations program (BUFFALO, Steinhardt et al. 2020, HST Program ID 15117) is a 101-orbit Cycle 25 HST program of prime ACS/WFC + parallel WFC3/IR imaging around all 6 of the clusters in the Hubble Frontier Fields program (HFF, Lotz et al. 2017). The BUFFALO program significantly expands the area imaged around each HFF cluster by a factor of about 3-4 times, in a total of 5 filters (ACS/WFC F606W and F814W, and WFC3/IR F105W, F125W, and F160W). This additional area had not previously been extensively observed by HST but was already covered by deep multi-wavelength data sets, including Spitzer and Chandra. As with the original HFF program, BUFFALO is designed to take advantage of gravitational lensing from massive clusters to simultaneously find high-redshift galaxies that would otherwise lie below HST detection limits and model foreground clusters to study the properties of dark matter and galaxy assembly. The expanded area is providing the first opportunity to study both cosmic variance at high redshift and galaxy assembly in the outskirts of the large HFF clusters.
For Abell 370, the image mosaics also contain additional archival imaging data from HST programs 11108, 11507, 11582, 11591, 13459, 13790, 14038, 14209, 14216 and 15117.
Data Products
Images
Image files are named according to the following convention:
hlsp_buffalo_hst_<inst>-<pix-scale>_<target>_<filter>_v1.0_<exten>.fits
where:
- <inst> is the instrument used, one of "wfc3-ir" or "acs-wfc".
- <pix-scale> is the output pixel scale of the mosaic, one of "30mas" or "60mas".
- <target> is the name of the target, e.g., "abell370".
- <filter> is the name of the filter used, e.g., "f606w".
- <exten> is the data file type extension, e.g., "drz.fits", "wht.fits".
Data file types:
| _drz.fits | Science image mosaic. |
| _wht.fits | Weights map for the mosaic. |
Catalogs
Catalog files from Pagul et al. 2023 are named according to the following convention:
hlsp_buffalo_hst_ir-weighted_<target>_multi_v2.0_<exten>
where:
- <target> is the name of the target, e.g., "abell370".
- <exten> is the data file type extention, i.e., "catalog.fits" or "readme.txt" (see table below).
Data file types:
| _catalog.fits | Catalog file |
| _readme.txt | Readme with additional catalog information |
Catalog files from Niemiec et al. 2023 are named according to the following convention:
hlsp_buffalo_<observatory>_multi_abell370_<filter>_v1.0_<exten>
where:
- <observatory> is the name of the observatory, one of "hst" or "hst-subaru".
- <filter> is the filter used, one of "f814w" or "multi".
- <exten> is the file extension (see Table below).
- <exten> is the data file type extention, i.e., "catalog.fits" or "readme.txt" (see table below).
Data file types:
|
_galcat-redseq.cat |
Red-sequence based cluster member catalog |
|
_galcat-full.dat |
Readme with additional catalog information |
|
_sl-final.dat |
Strong-lensing constraints catalog |
|
_sl-gold.dat |
Strong-lensing constraints catalogue, selecting only gold-class images |
| _sl.reg | DS9 region file showing the positions of the strong-lensing constraints |
|
_wl.fits |
Weak-lensing constrain catalog |
|
_lenstool.cat |
Weak-lensing constraints catalogue, combining the catalogue measured from the HST data in the BUFFALO field with the catalogue extracted from ground-based Subaru data (see Umetsu+2022) |
|
_readme.txt |
README file explaining catalog file contents |
Lens Model Files
Lens model files are named according to the following convention:
hlsp_buffalo_model_abell370_<fov>_niemiec-<lens-model>_v1.0_<exten>
where:
- <fov> is the field of view, one of the following
- "main": high-resolution map of main field
- "par": high-resolution map of parallel field
- "full": low-resolution map of the whole BUFFALO field
- <lens-model> is the type of lens model used (see Table A.1 of Niemiec et al. 2023).
- <exten> is the file extension. See table below for possible values and descriptions.
Data file types:
| _x-arcsec-deflect.fits |
Value of the deflection in the x (horizontal) axis normalized to DLS/DS=1 |
| _y-arcsec-deflect.fits |
Value of the deflection in the y (vertical) axis normalized to DLS/DS=1 |
| _gamma.fits |
Shear field at a DLS/DS=1 |
| _kappa.fits |
Convergence at a DLS/DS=1 |
|
_gamma1.fits |
Amplification matrix factor gamma1 at a DLS/DS=1 |
| _gamma2.fits |
Amplification matrix factor gamma2 at a DLS/DS=1 |
|
_zXX-magnif.fits |
Magnification map for a source at redshifts z=XX |
|
_psi.fits |
Lensing potential normalized to a DLS/DS=1 |
| _bayes.dat | Models parameters corresponding to the 100 model realizations in the "range_" folders (see below), from the MCMC sampling |
| _input.par | Parameters that were used to create the mass models using the Lenstool software |
In addition to the best-fit files described above, for each lens model the collection includes 100 maps corresponding to Markov Chain Monte Carlo (MCMC) realizations for each map type in subfolders, which are named according to the following convention:
range_<exten>/hlsp_buffalo_model_abell370_<fov>_niemiec-<lens-model>-<index>_v1.0_<exten>
where:
- <exten> is the file type, one of "gamma", "gamma1", "gamma2", "kappa", "psi", "xy-arcsec-deflect", "z01-magnif", "z02-magnif", "z04-magnif", "z09-magnif". See table above for descriptions
- <fov> is the field of view (see naming convention above for options).
- <lens-model> is the type of lens model used (see Table A.1 of Niemiec et al. 2023).
- <index> is the four-digit, zero-padded index of the MCMC realization, e.g., "0010" for the 10th realization.
Data Access
BUFFALO image files are available for download in the MAST Portal and via astroquery. Set the 'Provenance Name' filter to BUFFALO in the Portal Advanced Search to match all observations. The observations can also be retrieved programmatically using the astroquery.mast module. The example code below retrieves all products and allows you to download them via bash script. Note: total file size ~136 GB.
from astroquery.mast import Observations
all_obs = Observations.query_criteria(provenance_name="buffalo")
data_products = Observations.get_product_list(all_obs)
Observations.download_products(data_products, curl_flag=True)
-
A web-based interface for cross-mission searches of data at MAST or the Virtual Observatory
-
Search for and retrieve BUFFALO data products programmatically.
Direct Download
Image and catalog products are available for download via cURL script and via direct download via the table below:
| Cluster Name | cURL Script for Image Files | Direct Download Pagul et al. 2023 Catalogs | cURL Script for Niemiec et al. 2023 Lensing Catalog Files |
|---|---|---|---|
| Abell 2744 | 30 mas (17 GB) | 60 mas (4.1 GB) | Catalog | ReadMe | |
| Abell 370 | 30 mas (25 GB) | 60 mas (6.2 GB) | Catalog | ReadMe | Catalog Files |
| Abell S1063 | 30 mas (17 GB) | 60 mas (4.1 GB) | Catalog | ReadMe | |
| MACS 0416 | 30 mas (17 GB) | 60 mas (4.1 GB) | Catalog | ReadMe | |
| MACS 0717 | 30 mas (17 GB) | 60 mas (4.0 GB) | Catalog | ReadMe | |
| MACS 1149 | 30 mas (17 GB) | 60 mas (4.2 GB) | Catalog | ReadMe |
Lens model files for cluster Abell 370 are available for download via cURL scripts linked in the table below:
| Cluster | cURL Script by Lens Model Type | Total Download Size | |
|---|---|---|---|
| Abell 370 | |||
| A | 38 GB | ||
| B1 | 2.7 GB | ||
| B2 | 2.7 GB | ||
| B3 | 2.7 GB | ||
| C1 | 2.7 GB | ||
| C2 | 2.7 GB | ||
| D1 | 19 GB | ||
| D2 | 19 GB | ||
| E | 2.6 GB | ||