Mission Overview
Physics at High Angular resolution in Nearby GalaxieS ("PHANGS-HST")
Primary Investigator: Janice C. Lee
HLSP Authors: Leonardo Ubeda, Brad Whitmore, Dave Thilker, Janice C. Lee, Richard White, Gagandeep Anand, Stephen Hannon
Released: 2021-01-11
Updated: 2021-08-09
Primary Reference(s): Lee et al. 2021
Citations: See ADS Statistics
Source Data:
Color composites of PHANGS-HST imaging (Red: WFC3/UVIS F814W, Green: WFC3/UVIS F555W, Blue: WFC3/UVIS F438W+F336W+F275W) by Judy Schmidt.
Color composites of PHANGS-HST imaging (Red: WFC3/UVIS F814W, Green: WFC3/UVIS F555W, Blue: WFC3/UVIS F438W+F336W+F275W) by Judy Schmidt.
Color composites of PHANGS-HST imaging (Red: WFC3/UVIS F814W, Green: WFC3/UVIS F555W, Blue: WFC3/UVIS F438W+F336W+F275W) by Judy Schmidt.
Color composites of PHANGS-HST imaging (Red: WFC3/UVIS F814W, Green: WFC3/UVIS F555W, Blue: WFC3/UVIS F438W+F336W+F275W) by Judy Schmidt.
Color composites of PHANGS-HST imaging (Red: WFC3/UVIS F814W, Green: WFC3/UVIS F555W, Blue: WFC3/UVIS F438W+F336W+F275W) by Judy Schmidt.
Color composites of PHANGS-HST imaging (Red: WFC3/UVIS F814W, Green: WFC3/UVIS F555W, Blue: WFC3/UVIS F438W+F336W+F275W) by Judy Schmidt.
Overview
The PHANGS program is building the first dataset to enable the multi-phase, multi-scale study of star formation across nearby spiral galaxies, by combining Atacama Large Millimeter/submillimeterArray (ALMA) CO(2-1) mapping, Very Large Telescope/Multi Unit Spectroscopic Explorer (VLT/MUSE) optical spectroscopy, and Hubble Space Telescope (HST) UV-optical imaging. Here, the team provides data products from the PHANGS-HST Treasury survey, which is obtaining five band NUV-U-B-V-I imaging of the disks of 38 spiral galaxies at distances of 4-23 Mpc, and parallel V and I band imaging of their halos, to provide a census of tens of thousands of compact star clusters and associations. The combination of HST, ALMA, and VLT/MUSE observations will yield an unprecedented joint catalog of the observed and physical properties of ~100,000 star clusters, associations, HII regions, and molecular clouds.
Complementary PHANGS Data From ALMA
30 April 2021: Associated ALMA data are now publicly available though the PHANGS CANFAR site.
Data Release 1 (Jan. 11, 2021)
Provides the following image products for observations in the NUV-U-B-V-I bands for 29 out of 38 PHANGS-HST galaxies:
- FLC FITS file for each exposure with astrometric solutions updated based on GAIA DR2 sources.
- Combined DRC FITS images of individual pointings in each filter, each drizzled onto a common pixel grid defined for the galaxy target, also with astrometric solutions based on calibration to GAIA DR2 sources.
- Mosaicked DRC FITS images in each filter for 6 galaxies covered by multiple pointings (NGC 628, NGC 1300, NGC 1672, NGC 3351, NGC 3627, NGC 4321).
- ERR and EXP weight FITS images for individual pointings as well as mosaics.
Data Release 2 (August 09, 2021)
Completes the image product release for the full PHANGS-HST sample. It also provides convolutional neural network (CNN) models trained with deep transfer learning, for the classification of star clusters, and a sample Jupyter Python notebook that demonstrates how to use these models. NOTE: the notebook is delivered by the PHANGS-HST team, provided by MAST "as-is", MAST does not assume responsibility for the long-term maintenance of this notebook. Models with two different architectures, ResNet18 and VGG19-BN, along with the tutorial notebook, can be accessed in the Data Access section below.
Footprint Gallery
Below you can find a DSS image gallery of the PHANGS-HST galaxies with footprints from HST (blue), ALMA (red), and MUSE (cyan, available for 19/38 galaxies).
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Data Products
The "_err_drc_wht.fits" images are inverse variance maps incorporating contributions from the detector and the Poisson noise from the astrophysical scene, modulated by the number of integrations ("flc" images) drizzling into an output pixel and the effective exposure depth after masking, respectively. The "_exp_drc_wht.fits" images contain the effective drizzled exposure time per pixel in units of seconds.
The drizzled science and weight files have the following naming convention:
hlsp_phangs-hst_hst_<ins>_<target>_<filter>_v1_<etype>-drc-<type>.fits
where:
- <ins> = Name of instrument, either "wfc3-uvis" or "wfc-acs".
- <target> = Name of galaxy, e.g., "ngc1566", if a mosaic, will include "mosaic" after the galaxy name, e.g., "ngc1300mosaic".
- <filter> = Name of filter used, e.g., "f275w".
- <etype> = Either "exp" or "err", depending on the type of map.
- <type> = Type of image, either "sci" for science or "wht" for weight.
The individual calibrated, flat-field images have the following naming convention:
hlsp_phangs-hst_hst_<ins>_<target>-<id>_<filter>_v1_flc.fits
where:
- <ins> = Name of instrument, either "wfc3-uvis" or "wfc-acs".
- <target> = Name of galaxy, e.g., "ngc1566", if a mosaic, will include "mosaic" after the galaxy name, e.g., "ngc1300mosaic".
- <id> = HST ID of the observation, e.g., icdm17kcq.
- <filter> = Name of filter used, e.g., "f275w".
A set of 10 convolutional neural network models for cluster classification are stored in .tar bundles with the following naming convention:
hlsp_phangs-hst_hst_model_<type>_multi_v1_bundle.tar
where:
- <type> = Type of convolutional neural network architecture, one of "resnet" for ResNet18 or "vgg" for VGG19-BN.
Data file types:
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_exp-drc-sci.fits |
Drizzled science image. |
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_exp-drc-wht.fits |
Exposure time maps. |
| _err-drc-wht.fits | Inverse variance maps. |
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_flc.fits |
Individual calibrated, flat-fielded image. |
| _bundle.tar | Collection of CCN models of a given architecture. |
Data Access
Convolutional Neural Network Models And Turorial For Cluster Classification
Note: The Jupyter Python notebook was made available as received from the PHANGS-HST team. MAST is not responsible for the long-term maintenance of this notebook tutorial.
| ResNet18 Architecture (~894 MB) | VGG19-BN Architecture (~11 GB) | Notebook Tutorial |
|---|---|---|
| hlsp_phangs-hst_hst_model_resnet_multi_v1_bundle.tar | hlsp_phangs-hst_hst_model_vgg_multi_v1_bundle.tar | hlsp_phangs-hst_hst_model_any_multi_v1_starcluster-classification.ipynb |
HST Image Products
Note: Each "bundle" (a .tar.gz file) in the Image Links column is ~1-4 GB in size.
