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Mission Overview

A Spectroscopic Galaxy Evolution Survey with the Hubble Space Telescope (3D-HST)

 

Primary Investigator: Pieter van Dokkum

HLSP Authors: I. Momcheva, R. Skelton, K. Whitaker, G. Brammer

Released: 2014-09-03

Updated: 2026-09-25

Primary Reference(s): Momcheva et al. 2016, Brammer et al. 2012

DOI: 10.17909/T9JW9Z

Citations: See ADS Statistics

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3D-HST Figures

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3D-HST pointings

Figure 1. Layout of the 124 3D-HST pointings. Primary WFC3 F140W+G141 pointings are shown in blue with the pointing ID numbers as defined in the HST Phase II file. The locations of the parallel ACS F814W+G800L observations are shown in light green. Also indicated is the distribution of the 28 pointings covering the GOODS-North field from program GO-11600 that are incorporated into 3D-HST. The light gray polygons indicate the footprint of the CANDELS WFC3 imaging, including both the “wide” and “deep” components of that survey. Note that the relative sizes of the separate fields are not shown exactly to scale. (Figure from Brammer et al. 2012).

3D-HERSCHEL

A two-row, four-panel figure demonstrating that star formation rates derived from UV-to-350 micron photometry including Herschel far-infrared constraints are consistent with those derived from UV-to-24 micron photometry alone, across approximately 34,000 galaxies at 0.5 < z < 2.5. The close agreement between the two modeling approaches, shown in the bottom row as offsets clustering near zero across all stellar masses and redshift bins, validates the 3D-Herschel panchromatic SED modeling framework. The top row shows log star formation rate on the vertical axis versus log stellar mass on the horizontal axis, ranging from 10^8 to 10^11 solar masses, for four redshift bins: 0.5 to 1.0, 1.0 to 1.5, 1.5 to 2.0, and 2.0 to 2.5. Individual galaxies are shown as grey points. A solid blue line shows the median star-forming main sequence derived from UV-to-24 micron photometry alone, with a blue shaded region showing the 1-sigma scatter. A red dashed line shows the median sequence derived from UV-to-350 micron photometry including Herschel constraints, with a red shaded region showing the 1-sigma scatter. The bottom row shows the difference in log SFR between the Herschel-constrained and UV-MIR-limited fits on the vertical axis, ranging from approximately -0.5 to 0.5 dex, as a function of stellar mass. A green shaded band shows the running median and scatter of the offsets, which remain close to zero across all stellar masses and redshift bins, with grey horizontal reference lines at 0.0 and plus and minus approximately 0.2 dex.

Figure 2. The star-forming main sequence (SFR vs. stellar mass) across four redshift bins for ~34,000 galaxies in the 3D-Herschel sample, derived from Prospector-β SED modeling. The solid blue line shows fits using UV-to-24 µm photometry alone; the red dashed line shows fits incorporating the full UV-to-350 µm 3D-Herschel photometry including Herschel/PACS+SPIRE constraints. The bottom panels show the difference between the two sets of fits. The close agreement across all redshift bins and stellar masses demonstrates that the 3D-Herschel catalogs provide independent FIR constraints on dust emission and star formation, enabling self-consistent panchromatic SED modeling across the full galaxy population, including robustly constrained dust emission parameters unavailable from UV-MIR data alone.

Overview

3D-HST is a near-infrared spectroscopic survey with the Hubble Space Telescope designed to study the physical processes that shape galaxies in the distant Universe (GO-12177 & GO-12328; PI: Pieter van Dokkum). This Treasury program was allocated 248 orbits of HST time during Cycles 18 and 19. 3D-HST is surveying ~600 square arcminutes of well-studied extragalactic survey fields (AEGIS, COSMOS, GOODS-S, UKIDSS-UDS) with two orbits of primary WFC3/G141 grism coverage and two to four orbits with ACS/G800L coverage. 3D-HST now provides the critical third dimension - redshift - for ~10,000 galaxies at z>1. This is the epoch when ~60% of the star formation in the Universe took place, the number density of quasars peaked, the first galaxies stopped forming stars and the structural regularity that we see in galaxies today emerged. The 3D-HST project details can be found in "3D-HST: A Wide-Field Grism Spectroscopic Survey with the Hubble Space Telescope", Brammer et al., 2012, ApJ, 758L.

The survey is optimally designed for the study of galaxy evolution over 1 < z < 3.5. The science objectives include: disentangling the processes that regulate star-formation in massive galaxies, evaluating the role of environment and mergers in shaping the galaxy population, and resolving the growth of disks and bulges, spatially and spectrally.

Observations

The 248 3D-HST orbits are divided among 124 individual pointings, each observed for two orbits (figure above and table below). In order to schedule 3D-HST concurrently with CANDELS observations of the same fields over Cycles 18 and 19, the orientations of the fields were determined only after the observations were scheduled. The positions of the individual pointings were optimized to provide contiguous mosaics and maximum overlap between the primary WFC3 G141 and parallel ACS G800L observations. Owing to this optimization, fully 90% of the G141 mosaic will be covered by between two and four orbits of the ACS grism. Within the GOODS-South mosaic, four of the two-orbit visits are centered on the Hubble Ultra Deep Field (HUDF) at the same orientation. The GOODS-South pointings outside of the area with CANDELS coverage provide WFC3 grism spectroscopy of the HUDF09 and WFC3-ERS fields.

Field Program ID RA Dec N Pointings Image Region Files
AEGIS 12177 14:19:31  +52:51:00 30 image WFC3 / ACS
COSMOS 12328 10:00:29  +02:20:36  28 image WFC3 / ACS
GOODS-S 12177 03:32:31 -27:48:54 34 image WFC3 / ACS
HUDF 12177 03:32:39 -27:47:01 4 image WFC3
UDS 12328 02:17:26 -05:12:13 28 image WFC3 / ACS

 

The 28-pointing G141 grism coverage of most of the GOODS-N field from program GO-11600 (PI: B. Weiner) is incorporated into 3D-HST, as the observational strategy of these observations are nearly identical to that of 3D-HST. There are GOODS-N mosaics and weight images (image | regions) in the F125W, F140W and F160W WFC3 bands. These mosaics are available as part of the 3D-HST V3.0 data release. The F125W and F160W observations were taken as part of the CANDELS survey. Parallel ACS grism observations are available from GO-13420 (PI: Barro).

Previous Data Releases

The v3.0 release described in van Dokkum et al (2013), including deep HUDF spectra, can be found here.

The preliminary data release v0.5 accompanying the survey paper Brammer et al. (2012) can be found here.

3D-Herschel Update

2026-09-25: The 3D-Herschel collection (McNulty et al. 2026) extends the CANDELS/3D-HST legacy photometric catalogs (Skelton et al. 2014) by adding deblended Spitzer/MIPS 24 µm and Herschel/PACS+SPIRE far-infrared (FIR) photometry spanning 70–350 µm across four extragalactic survey fields: COSMOS, GOODS-South, GOODS-North, and UDS. The resulting UV-to-FIR photometric catalogs cover 0.3–350 µm and preserve the source IDs of the original 3D-HST catalogs to facilitate cross-matching. Herschel photometry was obtained via a deblending approach using prior positions from the existing HST-based source catalogs, enabling FIR flux measurements for individual galaxies in the crowded far-infrared images.

In addition to the photometric catalogs, 3D-Herschel provides stellar population synthesis (SPS) catalogs for ~41,000 galaxies at 0.5 < z < 2.5, derived using an emulator trained to reproduce Prospector-β Bayesian SED modeling results (Leja et al. 2019; Johnson et al. 2021). Two sets of SPS catalogs are provided per field: one fit to the full UV-to-FIR photometry (UV-FIR), and one fit to photometry limited to UV-24 µm (UV-MIR). Including Herschel FIR photometry reduces the age-dust-metallicity degeneracy inherent in UV-MIR-only SED fitting, yielding more robustly constrained stellar masses, star formation rates, and dust attenuation properties.

Primary Investigator: Katherine E. Whitaker
HLSP Authors: Seamus McNulty, Mimi Song, Katherine E. Whitaker, Joel Leja, Aubrey Medrano, Elijah P. Mathews, Mark Dickinson, Hanae Inami, Ivo Labbe, Danilo Marchesini, Alexandra Pope, Irene Shivaei

Data Products

3D-HST

The final release of the 3D-HST dataset was made available in October 2015 on the 3D-HST website. This v4.1.5 release as well as the 2014 v4.1 photometric release are mirrored and archived here. It covers all five 3D-HST/CANDELS fields: AEGIS, COSMOS, GOODS-N, GOODS-S and UDS. See Momcheva et al. (2015) and Skelton et al. (2014) for full descriptions of the data and methods. The v4.1.5 release includes:

  • Extracted WFC3 2D and 1D spectra for ~250,000 objects

  • Redshifts based on joint fits to the grism spectra and photometry for ~100,000 objects down to JH=26

  • Emission line fits for to all major emission lines down to JH=26

  • Best redshift catalog combining the spectroscopic, grism and photometric redshifts in the five fields

  • Stellar masses, UV+IR star formation rates, rest-frame colors in 22 bands for the grism redshift and best redshift catalogs

  • Extracted ACS 2D and 1D spectra for ~25,000 objects

 

Data file naming convention:

hlsp_3dhst_<telescope>_<instrument>_<field>_<filter>_<version>_<product-type>.<extension>

where:

  • <telescope> is the telescope used to obtain the data, for example "hst" or "spitzer"
  • <instrument> is the instrument used in the observation, for example "wfc3" or "acs"
  • <field> is the name of the target field, for example "aegis" or "cosmos"
  • <filter> is the filter used in the observation, for example "f125w" or "f160w"
  • <version> is the file version, for example "v4.0"
  • <product-type> is the type of data product, listed in the table below
  • <extension> is the file type: "fits", "tif", "pdf", etc.

Data product types:

_sci.fits
_orig-sci.fits

Drizzled science image, created with the final processed FLT files
_conv-sci.fits Convolved science image, PSF-matched to the F160W image
_wht.fits

Drizzled weight map, created with the final processed FLT files
_exp.fits

 Exposure Map
_nexp.fits

 Number of exposure Maps
_psf.fits Point Spread Function for each filter
_kernel.fits PSF kernel images

3D-Herschel

The 3D-Herschel files follow the naming convention:

hlsp_3d-herschel_<telescope>_multi_<field>_<wavelength>_v1.1_<product-type>.<extension>

where:

  • <telescope> is the telescope used to obtain the data, for example "hst" or "herschel"
  • <field> is the name of the target field, for example "goods-n" or "cosmos"
  • <wavelength> is the approximate wavelength range of the catalog, for example "uv-mir" or "uv-fir"
  • <product-type> is the type of data product: photometry catalog (phot-cat) or SPS catalog (sos-cat)
  • <extension> is the file type: "fits" or "txt"

Data product types:

_phot-cat.fits

Photometric catalog: UV-to-FIR photometric fluxes from 0.3–350 µm, extending the 3D-HST UV-MIR photometry with Spitzer/MIPS 24 µm and Herschel/PACS+SPIRE far-infrared measurements.
_sps-cat.fits

SPS catalog with Herschel (UV-FIR): Stellar population parameters (stellar mass, SFR, dust attenuation, and more) derived from Prospector-β SED fits to the full UV-to-FIR photometry.
_sps-cat.fits SPS catalog without Herschel (sps-cat, UV-MIR): Stellar population parameters derived from Prospector-β SED fits to photometry limited to UV-24 µm, for comparison with Herschel-inclusive fits.

Data Access

MAST Portal and Astroquery

The 3DHST imaging 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).

Note that only the imaging products are available through this method. For the catalog data and auxiliary files, please use the links in the "Direct Download" section below.

  • In the MAST Search Portal, set the Provenance Name filter to "3DHST" 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 3DHST products
all_obs = Observations.query_criteria(provenance_name="3DHST")
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 data for this HLSP are available for direct download using the links in the tables below:

data-tables

Code Examples

The authors of this HLSP have provided a few code examples for working with the data in Python, shown below.

Star-Forming Main Sequence with 3D-Herschel

Please find below a short Python tutorial demonstrating how to read and make a basic plot from the 3D-Herschel FITS catalogs:

import numpy as np
import matplotlib.pyplot as plt
from astropy.io import fits
from astropy.table import Table, join

# ── Load photometric catalog (FITS) ──
phot = Table.read('hlsp_3d-herschel_hst-spitzer-herschel_multi_cosmos_uv-fir_v1.1_phot-cat.fits')

# ── Load SPS catalog with Herschel (FITS) ──
sps = Table.read('hlsp_3d-herschel_hst-spitzer-herschel_multi_cosmos_uv-fir_v1.1_sps-cat.fits')

# ── Apply recommended use flag ──
matched_phot = join(phot, sps, keys='id', join_type='inner')
# ── limit phot cat to match sps cat on ID ──
use = matched_phot['use_phot'] == 1
phot = matched_phot[use]
sps = sps[use]

# ── Plot: star-forming main sequence ──
fig, ax = plt.subplots(figsize=(7, 5))

sc = ax.scatter(
    sps['survmass_50'],       # log stellar mass [log Msun]
    np.log10(sps['sfr100_50']),  # log SFR [log Msun/yr]
    c=sps['z_best'],
    cmap='plasma',
    s=1,
    alpha=0.4,
    vmin=0.5, vmax=2.5
)

cbar = fig.colorbar(sc, ax=ax)
cbar.set_label('Redshift', fontsize=12)
ax.set_xlabel(r'log $M_*$ [$M_\odot$]', fontsize=12)
ax.set_ylabel(r'log SFR [$M_\odot$ yr$^{-1}$]', fontsize=12)
ax.set_title('3D-Herschel COSMOS — Star-Forming Main Sequence')
ax.set_xlim(7.5, 12)
ax.set_ylim(-2, 2.5)
plt.tight_layout()
plt.savefig('3dherschel_mainsequence_cosmos.png', dpi=150)
plt.show()

Citations

Please remember to cite the appropriate paper(s) below and the DOI 10.17909/T9JW9Z if you use these data in a published work. 

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

When using data from the 3D-HST survey, please include the following acknowledgement:

This work is based on observations taken by the 3D-HST Treasury Program (GO 12177 and 12328) with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

 

References

refs-container

  • Brammer et al. 2012

    3D-HST: A Wide-field Grism Spectroscopic Survey with the Hubble Space Telescope

  • Momcheva et al. 2016

    The 3D-HST Survey: Hubble Space Telescope WFC3/G141 Grism Spectra, Redshifts, and Emission Line Measurements for ~ 100,000 Galaxies

  • Skelton et al. 2014

    3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts, and Stellar Masses

  • Grogin et al. 2011

    CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey

  • Koekemoer et al. 2011

    CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey—The Hubble Space Telescope Observations, Imaging Data Products, and Mosaics

  • Whitaker et al. 2014

    Constraining the Low-mass Slope of the Star Formation Sequence at 0.5 < z < 2.5

  • McNulty et al. 2026

    3D-Herschel: Constraining Dust Emission with Panchromatic Modeling of 3D-HST Galaxies