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Mission Overview

The HST-Hyperion Survey (HST-HYPERION)

 

Primary Investigator: Brian Lemaux

HLSP Authors: Ben Forrest

Released: 2026-04-30

Updated: 2026-04-30

Primary Reference(s):  Forrest et al. 2025

DOI: 10.17909/5kka-ms10

Citations: See ADS Statistics

Read Me

Source Data:

 

HST-Hyperion

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HST-Hyperion Pointings

The sky footprint of observations from the HST-HYPERION project. Coordinates Right Ascension (RA) on the x-axis, and Declination on the y-axis. Each pointing is plotted on this projection as an angled square shape, with observations from 3D-HST (Proposal ID 12328) in red and HST-Hyperion (Proposal ID 16684) in Blue. The red 3D-HST observations are in the center of the field, whereas the blue HST-Hyperion observations are mostly around the edges.

Figure 1. HST/WFC3/G141 pointings used in this work. Direct F140W images from the 3D-HST survey are outlined in red, while direct F160W images from the HST-Hyperion survey are outlined in blue. The dark gray shows the 7 peaks of >5σ overdensity from O. Cucciati et al. (2018). The north and northwest regions each have two peaks overlapping in projection.

HST-Hyperion Sources

A sky map showing the location of spectroscopically confirmed sources from the HST-HYPERION project. The overdensity contours are plotted in shades of gray as irregularly-shaped blobs. Various points are plotted over the contours showing the location of spectroscopic sources: blue circles for targets identified in HST-Hyperion, red stars for C3VO MOSFIRE, and yellow triangles or white circles for other literature.

Figure 2. Spectroscopically confirmed sources in the region of the Hyperion protosupercluster. The projected 5σ, 3.5σ, and 2σ overdensity contours from O. Cucciati et al. (2018) are shown in shades of gray. Spectroscopic redshifts from the zCOSMOS, DEIMOS10k, and VUDS field surveys with 2.35 < zspec < 2.65 and qfs, z = 3,4 are shown as black rings, while spectroscopically confirmed members from targeted works are shown as gold triangles (C. M. Casey et al. 2015; C. Diener et al. 2015; Y. K. Chiang et al. 2015; T. Wang et al. 2016). Members identified in the C3VO MOSFIRE follow-up of Hyperion with the same cuts are shown as red stars. HST-Hyperion sources with 2.35 < zgrism < 2.65 and qfg,z = 3,4,5 are blue. The HST-Hyperion program has resulted in 192 potential members in this redshift range with high-quality grism redshifts.

Overview

This HLSP collection provides two catalogs and associated data products from the analysis performed by the HST-Hyperion Survey. This includes HST/WFC3/F160 and G141 data from PID 16684 (PI Lemaux) as well as reprocessed HST/WFC3/F140 and G141 data from the 3D-HST survey in the COSMOS field. Data were reduced uniformly using the grizli package (v1.9.5; Brammer & Matharu, 2021). Image mosaics of F140 and F160 data were used for source detection and all sources with magnitudes <25 AB had their G141 data analyzed and included in the final catalogs. More details are provided in the accompanying paper, Forrest et al. (2025): 'The HST-Hyperion Survey: Grism Observations of a z~2.5 Protosupercluster.'

Version 1.0 includes:

  • 2 primary catalogs and 1 comment dictionary (ASCII)
  • Images (FITS)
    • F140W images for individual pointings observed in 3D-HST in COSMOS
    • F160W images for individual pointings observed in HST-Hyperion
    • G141 images for individual pointings observed in HST-Hyperion
    • F140W and F160W mosaics for 3 different regions (FITS)
  •  2D spectrum for each object in the catalogs (FITS)
  •  1D extracted spectrum for each object in the catalogs (FITS)

Data Products

Data file naming convention:

hlsp_hst-hyperion_hst_wfc3_<target-name>_<filter>_v1_<file-type>.<extension>

where:

  • <target_name> is the identifier or name of the target
  • <filter> is the filter or grating used in the observation: "F160W", "F140W", or "G141"
  • <file-type> is the type of data product: catalogs ("el-cat" or "z-cat"), images ("drz-sci" and "drz-sci-mosasic")  and spectra ("spec1d", "spec2d"). See below for more detail.
  • <extension> is the file extension: typically "fits" or "txt"

Catalogs

This collection includes a redshift catalog and an emission line catalog. These compile all sources visually inspected by the HST-Hyperion team, including sources with mHST<25 as detected from HST/WFC3/F160W imaging from HST-Hyperion observations and HST/WFC3/F140W imaging from 3D-HST observations, for a total of 12813 sources.

Catalog file types:

_el-cat.txt Emission line catalog. Contains equivalent width measurements for emission lines including [OII]3727, Hb4861, [OIII]5007, and Ha6563 for each extracted spectrum.
_z-cat.txt Redshift catalog. Contains coordinates, magnitude measurements, and redshift estimates for each source.

_z-cat-dict.txt

 Supplementary redshift catalog dictionary providing documentation and definitions for the columns in the redshift (z-cat) catalog.

 

Images

Image products in this collections include F140W images for individual pointings observed in 3D-HST in COSMOS, F160W and G141 images for individual pointings observed in HST-Hyperion, and combined F140W and F160W mosaics for 3 different regions (FITS).

Image file types:

_drz-sci.fits Drizzled Science Images. F140W images are re-reduced observations for each pointing from the 3D-HST survey. F160W images are reduced observations for each pointing from the HST-Hyperion survey. G141 images are the reduced grism observations from the 3D-HST and HST-Hyperion surveys, with the file having the same base string as the associated image.
_drz-sci-mosaic.fits Drizzled image mosaic. Mosaics files are combined F140W or F160W images in three separate regions corresponding to different density peaks in the Hyperion structure.
_drz-wht-mosaic.fits Weight map file for the image mosaics.

Spectra

2D- and 1D- grism spectra have been extracted for 12813 sources detected from the imaging products.

Spectra file types:

_spec1d.fits The 1D spectra files, which include dimensional extracted spectra, which include the spectral wavelength, flux, and error, as well as contamination, continuum, and line models extracted from the combined spectrum.
_spec2d.fits

The 2D spectra files, which include extensions for the 2D spectrum ('SCI'), weight ('WHT'), contamination model ('CONTAM'), target model ('MODEL'), and convolution kernel ('KERNEL'). There is a set of these five extensions for each position angle observed for a given target as well as a final set for the combined observations.

 

Data Access

MAST Portal and Astroquery

The HST-HYPERION images and spectral data products are available in the MAST Search Portal (web-based, cross-mission search interface) and Astroquery (Python package to search for and download files from Python scripts you write).

  • In the MAST Search Portal, set the Provenance Name filter to "HST-HYPERION" in an Advanced Search to find these data. The user guide for how to search and download products using the MAST Portal is available here.
  • For Astroquery, the following example code demonstrates how to search for and download these products. This code assumes that you want to download all products from this HLSP, so you may want to consider narrowing down your search for large HLSPs (> 10 GB) or those with many individual files (> 10k). You can find more astroquery.mast tutorials here.
from astroquery.mast import Observations
# Search for all HST-Hyperion products
all_obs = Observations.query_criteria(provenance_name="hst-hyperion")
data_products = Observations.get_product_list(all_obs)
# Print the number of data products that would be downloaded
print(len(data_products))
# Download data
Observations.download_products(data_products)

  • MAST Portal

    Link to the MAST Portal Webpage
    A web-based interface for cross-mission searches of data at MAST or the Virtual Observatory.
    Portal

  • MAST Astroquery

    Search for and download data products for this HLSP programmatically in Python.
    MAST Astroquery

Direct Download

The catalogs for this HLSP are available for direct download using the links in the table below:

Catalog File
Emission Line Catalog hlsp_hst-hyperion_hst_wfc3_hyperion_f140w-f160w-g141_v1_el-cat.txt
Redshift Catalog hlsp_hst-hyperion_hst_wfc3_hyperion_f140w-f160w-g141_v1_z-cat.txt
Redshift Catalog Dictionary hlsp_hst-hyperion_hst_wfc3_hyperion_f140w-f160w-g141_v1_z-cat-dict.txt

 

Citations

Please remember to cite the appropriate paper(s) below and the DOI 10.17909/5kka-ms10 if you use these data in a published work. 

Note: These HLSP data products are licensed for use under CC BY 4.0.

References

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