Mar 042014

The Frontier Fields has released the version 1.0 data products of MACSJ0416.1-2403!  This completes the first epoch of observations for this cluster.

These v1.0 mosaics include all the ACS and WFC3/IR primary and parallel data obtained to date on this cluster from the Frontier Fields program 13496 (PI: J Lotz) and ancillary programs.  They have been fully recalibrated relative to the v0.5 mosaics that we released each week throughout the course of this epoch.

For ACS, the v1.0 mosaics incorporate new bias and dark current reference files, along with CTE correction and bias destriping. The WFC3/IR v1.0 mosaics have improved masking for persistence and bad pixels, and in addition have been corrected for time-variable sky emission that can occur during the orbit and can otherwise impact the up-the-ramp count-rate fitting if not properly corrected. We have also refined the astrometric corrections and masking for satellite trails, bad pixels and other defects. In addition, we are also releasing a “beta” reduction of ACS mosaics that have been created with a new self-calibration approach.

MACS0416 in seven filters

MACS0416 in seven filters; ACS/WFC F435W + F606W (blue), ACS/WFC F814W + WFC3/IR F105W (green), WFC3/IR F125W + F140W + F160W (red).

All of the v1.0 mosaics can be obtained from the MAST Frontier fields webpage or directly from the v1.0 webpage.

What will you discover in these recalibrated mosaics?

 Posted by at 1:37 pm
Feb 262014

The Jansky-VLA Legacy Survey of the Frontier Fields will provide deep (1uJy/bm) dual-band (3 and 6 GHz) imaging over the full HST and Spitzer coverages for the lensing cluster fields MACSJ0717, MACS1149, and MACS0416.

Using the Very Large Array in both A- and C-configurations, we will generate maps having 0.65 and 0.33 arc-second resolution, respectively.  These deep images will have a significant and lasting impact for the coming decades, providing unique observations that will be used to:

  • Study the relationship between star formation, radio spectral index, and starburst size for galaxies on and off the main sequence out to z ~ 5, at high spatial resolution using a wavelength immune to the effects of obscuring dust.
  • Track the co-evolution of AGN and star-formation as a function of redshift through robust measurements of the brightness temperature, radio spectral index, and polarization of nuclear emission in hundreds of galaxies spanning more than two orders of magnitude in luminosity.
  • Characterize the distribution of star formation on sub-kpc scales within disk galaxies at z > 1, which is only achievable as a result of the magnification provided by the lensing clusters.
  • Detect Milky Way-like galaxies in the intermediate redshift lensing clusters, yielding a census of star formation as a function of environment when quenching in clusters was most efficient.

Once the final two Frontier Fields are approved, we plan to complete the survey by additionally mapping the remaining Frontier Fields that are accessible to the VLA (i.e., Abell 2744 and Abell 370).


VLA coverage at 3 GHz (black circles) and 6 GHz (magenta circles), vs. the HST WFC3/IR and ACS pointings for the clusters (red and blue center boxes) and parallel fields (outer boxes).

Legacy Value:
These data will have a lasting legacy value for the community for years to come and undoubtedly contribute to a large number of Ph.D. theses studying the radio properties of galaxies and galaxy evolution in general. For instance, this program will explore an uncharted region of observational parameter space (e.g., the polarized sky at uJy levels) by making the deepest map towards a massive cluster at these frequencies, yielding the possibility of finding new classes of intrinsically faint sources and almost certainly leading to community-led science projects that are beyond those described above (e.g., stacking analyses to improve detection limits for the highest redshift sources and confirm UV-radio star formation rate conversions as a function of redshift and luminosity).

These radio observations will also provide some of the deepest cosmological radio data ever taken. The proposed 1 uJy RMS depth at 3 GHz is a factor of 2 and 1.5 times deeper than current/ongoing observations of COSMOS (2 uJy at 3GHz) and GOODS-N (2.5 uJy at 1.4GHz), respectively, even before lens amplification.

Eric Murphy
PI of the Jansky-VLA Legacy Survey of the Frontier Fields
U.S. Planck Data Center, IPAC Pasadena, CA

 Posted by at 5:06 pm
Feb 052014

Nicolas Laporte and collaborators have compared the deep HST images of Frontier Fields cluster Abell 2744 to 50 hours of Spitzer IRAC imaging.  One of the best candidates for a distant z~8 galaxy — detected in the HST  WFC3/IR images — disappears in the IRAC 3.6 micron image and reappears in the IRAC 4.5 micron image.   The best explanation for these strange colors is the appearance of very strong emission lines from oxygen and hydrogen ([OIII] and H-beta) which fall into the 4.5 micron band at a redshift of z~7.98.

The paper has been accepted for publication in the A&A Letters.

Check out the details:

JWST will be able to provide conclusive observations with both NIRSpec and NIRCam grism observations.  Bring on 2018 and the launch of JWST!

 Posted by at 12:37 pm
Jan 172014

The first epoch of MAC0416.1-2403 has started and we have made available the first v0.5 data release for the community!

The main cluster is being observed with ACS, while WFC3/IR sees the parallel field during this epoch.

This first release includes the F435W, F606W, and F814W filters on ACS and the F105W, F125W, F140W, and F160W filters on WFC3/IR.  This release also includes archival CLASH data on the main cluster.

Note that our data quality team has identified and masked some regions of the WFC3/IR mosaics that are impacted by persistence from unrelated observations.  All of the unmasked region of these mosaics are at full depth.

For all of the data, including this latest release, please see the Frontier Fields MAST archive web page.

Here we go with another cluster!

 Posted by at 12:30 pm
Jan 102014

The Winter AAS meeting at the National Harbor was a huge success, with many great plenary talks, fabulous poster sessions, and our very own press release!

The Frontier Fields Abell 2744 and its parallel field data are complete and is out in full, glorious color!  Click through for the official press release.  Click here to see video of the press conference at the AAS (Jennifer Lotz presents between 02:45 and 08:50 in the video).  You can also watch the associated, public outreach video.

Jennifer Lotz talks about the Frontier Fields with Alberto Conti and Tony Darnell.

Jennifer Lotz talks about the Frontier Fields with Alberto Conti and Tony Darnell. (courtesy of Brandon Lawton)

These Frontier Field Hangouts can be found here:

Jennifer Lotz explains the Frontier Fields at the NASA booth.

Jennifer Lotz explains the Frontier Fields at the NASA booth. (courtesy of Brandon Lawton)

Other discussions at the JWST booth can be viewed here.

The Frontier Fields had a great showing for Abell 2744 and data is already rolling in on our second cluster, MACS0416.  Check it out!

 Posted by at 5:24 pm
Jan 032014

The Frontier Fields will be a highlight of next week’s AAS Meeting near Washington, D.C.  Visit the HST booth and chat with us!

Here are some of the ways you can experience the Frontier Fields data next week:

  • Monday, 8:30 am:  Bob Williams gives the Kavali Foundation Lecture on The Hubble Deep Field and its Legacy
  • Tuesday,  9am-6pm:  7 Frontier Fields posters in 254. Surveys and Large Programs
    • 254.01 – The HST Frontier Fields  – J. Lotz et al.
    • 254.02 – The HST Frontier Fields: Science Data Pipeline, Products, and First Data Release – A. Koekemoer et al.
    • 254.03 – The HST Frontier Fields: DrizzlePac Workflow  – R. Avila et al.
    • 254.04 – The HST Frontier FIelds: Gravitational Lensing Models Release  – D. Coe et al.
    • 254.05 – The Frontier Fields Supernovae Survey  – S. Rodney
    • 254.06 – First results from the HST Grism Lens-Amplified Survey from Space (GLASS) – X. Wang et al.
    • 254.07 – The Ultraviolet Frontier: Deep near-UV imaging of the Hubble Frontier Fields – B. Siana
  • Tuesday, 10am:  Spitzer Special Session  (talks) -
    • 213.03 – Pushing the Frontiers to z>10 with Spitzer Space Telescope — P. Capak
  • Tuesday , 2:15pm:  Press release
  • Wednesday,  5pm:  NASA Special Presentations, booth #224, The Frontier Fields – J. Lotz

We’d love to see you at the press release, talks, poster session and HST booth!

 Posted by at 5:08 pm
Dec 172013

Now that the first epoch of Abell 2744 observations has completed, we are releasing the v1.0 data products.  These are products include all 70 orbits on the main cluster with WFC3/IR (in F105W, F125W, F140W and F160W) and on the parallel field with ACS (in F435W, F606W, F814W).

The v1.0 data products are made from a complete reprocessing, including these steps:

  • recalibration of exposures using the latest, up-to-date reference files and improving the bad pixel and cosmic ray rejection
  • exposures in all filters are combined with other observations, as available, to make the deepest possible mosaics
  • for ACS data, an additional “self-calibration” step is included, which improves both the calibration and alignment
  • for WFC3 data, refined flagging and removal of pixels affected by observational anomalies, including persistence, detector defects, and time-variable sky background.

These complete products are expected to reach final depths of ~28.7 – 29th ABmag. Complete details on these specially crafted calibrations can be found in the Frontier Fields Science Data Pipeline and Products Readme file.  We have made every effort to document all the special handling the Frontier Fields data is receiving, so that everyone can make use of what we have learned works best.

Mosaics are distortion-corrected, combined and registered to a common pixel scale, ready for you to use immediately!  You can find all of these products at our MAST web page:

Our data is ready to be mined for science!

 Posted by at 2:52 pm
Dec 052013

The lensing maps for all six Frontier Fields clusters were released November 27, 2013.  The MAST lensing model web site provides

  • interactive interfaces for exploring the mass (kappa), shear (gamma), and magnification maps pre-computed at z = 1, 2, 4, and 9
  • a tool to deliver magnification estimates with uncertainties from all models at a given RA, DEC, and redshift
  • direct access to the lensing models.

These models were produced by five independent groups:

  • M. Bradac (PI)  A. Hoag, and collaborators
  • Clusters as TelescopeS Team (CATS):  H. Ebeling (PI), J. Richard, M. Limousin, and collaborators
  • J. Merten (co-PI) ,  A. Zitrin (co-PI), and collaborators
  • K. Sharon (PI), T. Johnson, and collaborators
  • L. Williams (PI) and collaborators

We hope the community sees these models as valuable resources.  If you find them useful, please acknowledge these map makers according to the instructions at the bottom of the web site.  Thank you!

Here’s just one example of what you can see with the interactive viewer for MACSJ0416.1-2403, of which data will be coming soon!  Clicking on the image below will take you directly to the interactive viewer.

Sharon, et al. lensing models of MACSJ0416.1-2403, showing z = 1, 4, 9.

K. Sharon, T Johnson, et al. magnification maps of MACSJ0416.1-2403, showing z = 1 (blue), 2 (green), 9 (red).

You can now go explore all of the Frontier Fields cluster lensing maps!

 Posted by at 9:00 am
Dec 042013

We now have all the data from epoch 1 of Abell 2744 in hand!

HST obtained the last exposures of this epoch on 28 November 2013. This completes a total of 70 orbits of WFC3/IR imaging on the main cluster and ACS imaging on the parallel field.  Other, contributing programs (by B. Siana, S. Rodney, and R. Dupke) added a combined 38 orbits of ACS and WFC3/IR data.  Please see the Frontier Fields MAST web site for full details.

Our fast-turnaround v0.5 mosaics of all the above data (v0.5-20131129, released on November 29, 2013) are now available.  These mosaics are full-depth, but the calibrations are still preliminary.

During the next couple of weeks, we will be creating the recalibrated, version 1.0 of this dataset.  Recalibrations for WFC3/IR data will include:

  • improved persistence correction
  • bad pixel masking
  • time-variable sky treatment,

while for ACS we expect to also include:

  • improved bad-pixel masking
  • updated darks and biases
  • possibly self-calibration of all the ACS exposures.

The details of these recalibration steps are still being refined, so stay tuned!

 Posted by at 10:18 am
Nov 112013

We are on a roll! Specifically, we are rolling out weekly releases of the latest high-level science products for the Frontier Fields as the data is acquired.

We have the to-date, combined images of the Abell 2744 cluster for each of the WFC3/IR filters (F105W, F125W, F140W, F160W) and of the parallel field for each of the ACS filters (F435W, F606W, F814W) available for download.

For all of the images and complete information, see, where all of the latest releases are being announced, along with direct links to all the full-depth combined mosaics.

Start your code engines!

 Posted by at 2:06 pm