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Grism Lens-Amplified Survey from Space ("GLASS")

PI: Tommaso Treu (UCLA)
Treu et al. 2015, ApJ, 812, 114
Schmidt et al. 2014, ApJL, 782, 36
External Team Page: http://glass.astro.ucla.edu
Publication Compilation: http://glass.astro.ucla.edu/publications/

Introduction

Data Products

Data Access

README

Latest Updates
23 Feb. 2017 - Abell 2744 and MACS 0416 have Version 2.0 of the redshiftcatalog.txt files.
05 Oct. 2016 - Abell 370 and MACS 1423 have Version 2.0 of the redshiftcatalog.txt files. These include some updated redshifts for targets, and a few new targets.
04 Dec. 2015 - The *glassmaster.cat catalog files had some columns missing and/or mis-matched, which have been fixed.
30 Nov. 2015 - The initial redshift catalog for RXJ 1347 contained incorrect source coordinates, which has been fixed.

Introduction

First multiply imaged, strongly lensed supernova . Improved mass reconstruction of Abell 2744.
Gas-phase metallicity gradients of galaxies at z~2.
GLASS is a cycle-21 large program (Program 13459) with the Hubble Space Telescope, targeting 10 massive clusters, including the 6 Frontier Fields, using the WFC3 and ACS grisms. The program consists of 140 primary orbits (with the G102 and G141 grisms) and 140 parallel orbits (with the G800L grism). Using the clusters as cosmic telescopes, GLASS is taking spectra of faint background galaxies with unprecedented sensitivity and angular resolution. GLASS has three primary science drivers, although a variety of other science investigations are possible in combination with existing and planned imaging campaigns like the Frontier Fields Initiative and CLASH.

The key science drivers of GLASS are:

  • To shed light upon the role of galaxies in reionizing the universe, the topology of high redshift intergalactic/interstellar medium and on Lyman alpha escape fraction.
  • To study gas accretion, star formation and outflows by mapping spatially resolved star formation and metallicity gradients in galaxies at z = 1.3 - 2.3.
  • To study the environmental dependence of galaxy evolution, by mapping spatially resolved star formation in galaxies in the cluster cores and infalling regions.

Data Products

The data products from each of the ten clusters are organized into subdirectories based on the cluster name. Several files are available for each cluster and each extracted object. We provide a brief summary below, for full details, consult the README file. Bundles are identified in bold text below.

  1. _inter.fits = Full FoV interlaced grism observation, from which individual targets are extracted. There can be up to four of these (one for each position angle + grism combination). There are also .png preview images for each one.
  2. _intermodel.fits = Model of the full FoV interlaced grism observation. There can be up to four of these (one for each position angle + grism combination). There are also .png preview images for each one.
  3. _align-drz.fits = Image used as alignment reference.
  4. _align-drz-seg.fits = SExtractor segmentation maps, based on the CLASH SExtractor parameters, used for object extraction and generation of the contamination model.
  5. _glassgigcatalog.txt = modified GiG output catalog that includes rating of the contamination and potential defects, as well as cross-matched CLASH IDs of objects from *objle24.tar.gz.
  6. _glassmaster.cat = SExtractor catalog corresponding to the *align-drz-seg.fits file. Includes all sources, not just those with redshift measurements.
  7. _redshiftcatalog.txt = Redshift catalog from visual inspection with GiGz, using the automatic redshift fits, CLASH photometry, and potential emission lines identified with GiG as prior information.
  8. _sextractorparam.sex = SExtractor parameter file from the alignment image.
  9. _objgt24.tar.gz = Tarball containing the data products for all faint objects with MAGAUTO > 24. Note these files are several GB in size.
  10. _objle24.tar.gz = Tarball containing the data products for all bright objects with MAGAUTO <= 24. Note these files are several GB in size.
  11. id?????/ = Subdirectory containing the data products for this extracted object. Note that only objects in the redshift catalog have their own sub-directires. To get data for all objects, download the "m≤24" or "m>24" tar bundles. The contents for the sub-directories are as follows:
    1. _1d.fits = Binary table of the 1D extracted spectrum, including wavelengths, fluxes, uncertainties, and contamination level estimates.
    2. _1d.png = Plot of the extracted spectrum.
    3. _2d.fits = The extracted 2D grism spectrum for this object.
    4. _2d.png = Plot of the extracted 2D spectrum, contamination model, continuum model, and the contam. + cont. corrected 2D spectrum.
    5. _2dzfit.png = The 2D spectrum of model continuum from the automatic redshift fit in the "zfit" file.
    6. _zfit.dat = The resulting redshift from the automated fitting to the grism data using the CLASH photometry.
    7. _zfit.fits = Estimated 1D and 2D continuum from the automatic redshift fit to the grism data using the CLASH photometry.
    8. _zfit.png = Figure summarizing the individual automatic redshift fits in "zfit" and comparison with the CLASH photometry.
    9. _zfit-pz.fits = The p(z) grids for the automatic redshift fits of the individual spectra.
    10. _1dstack.fits = Stack of the 1D spectra.
    11. _2dstack.fits = Stack of the 2D spectra.
    12. _2dstack.png = Figure showing the 2D stacked spectra at both position angles.
    13. _2dmosaic.pdf = Overview figure displaying the various extensions of the "2d.fits" files and an SED created by cross-matching with the CLASH photometry.
    14. _zfitplot.png = Figure summarizing the automatic redshift estimates from the "zfit" and comparing them to the photometry from CLASH (represented by blue curves).
    15. _zgrism.txt = The p(z) of the average p(z) from an automatic estimate of the redshift, combining the CLASH photometry with each of the spectra at the two position angles.
    16. .tar.gz = Tarball containing all the above files for the individual object.
    17. _web.{pdf,png} = Version of the "2dmosaic.pdf" used in the HTML pages.

Data Access

  1. Click on "LOAD" to visit a page containing the extracted target table for the redshift catalog (#7 in the list of products above) of that cluster. Each extracted target has a "quick-look" summary plot, as well as links to download that target's data products, or visit that target's "Details" page that provides plot and links to all the data products for that target.
  2. Use the links below "LOAD" to download "full-field" files for that cluster: "drz" = Alignment reference image, "seg" = SExtractor segmentation map, "redshift" = redshift catalog, "source" = SExtractor source catalog, "SExt" = SExtractor parameter file, "GiG" = GiG output catalog.
  3. Two "tar.gz" files are also provided below the "LOAD" link: "m≤24" contains all data products for bright sources with MAGAUTO ≤ 24, while "M>24" contains all data products for faint sources with MAGAUTO > 24.
  4. If you prefer to browse and download files directly through your web broswer, click on the "BROWSE" link to access a cluster's data products. Note that only objects from the redshift catalog (#7 in the list of products above) have their own sub directories here. To obtain data for any object in the Source Catalog (#6 in the list of products above) please download the tarballs for the bright and/or faint objects (#9 and #10 in the products above).

Abell 370
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
Abell 2744
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
MACS 0416
LOAD
Drz. Img.
Seg. Map
Redshift Cat*
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
Z-to-Master
Master Cat.
MACS 0717
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
MACS 0744
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
MACS 1149
LOAD
Drz. Img.
Seg. Map
Redshift Cat*
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
Z-to-Master
Master Cat.
MACS 1423
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
MACS 2129
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
RXJ 1347
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
RXJ 2248
LOAD
Drz. Img.
Seg. Map
Redshift Cat.
Source Cat.
SExt. Param.
GiG Cat.
m≤24 (tar.gz)
m>24 (tar.gz)
BROWSE
*The GLASS redshift catalog only includes sources within 0.1" of a source from the master (HST+VLT+KECK for MACS1149, CLASH-Hubble Frontier Fields for MACS0416) redshift catalog. These are the sources that appear in the page displayed via the "Load" link.
Look-up table containing the GLASS positions, GLASS IDs, master catalog positions, and master IDs for redshift sources.
Master redshift catalog containing sources from combined analysis of HST, VLT, and Keck observations (for MACS1149) or CLASH-Hubble Frontier Fields observations (for MACS0416).