Frontier Fields Catalogues

UNVEILING THE POWER OF THE DEEPEST IMAGES OF THE UNIVERSE

Main page | ASTRODEEP homepage | HST Frontier Fields Survey at STScI | Download the full catalogues | Papers : Merlin et al. 2016 , Castellano et al. 2016

Documentation

Introduction

We present the public release of the first complete catalogues of Frontier Fields Abell-2744 and MACSJ-0416 cluster and parallel pointings.

The catalogues include multi-band photometry (8 HST bands, deep Ks from the HAWK-I FF program, and Spitzer-IRAC 3.6 and 4.5 um), magnification, photometric redshifts and rest-frame properties, plus a variety of diagnostic information. The cluster pointings have been analysed following a multi-step procedure to remove foreground emission from intra-cluster light and very bright galaxies. Photometry from low-resolution IR bands has been derived with T-PHOT.

Two papers describing in details the catalogues and the procedures followed to obtain them have been submitted to Astronomy and Astrophysics and are available on the arXiv:

• Paper  I: The ASTRODEEP Frontier Fields Catalogues: I - Multiwavelength photometry of Abell-2744 and MACS-J0416, Merlin et al. 2016 ,
• Paper II: The ASTRODEEP Frontier Fields Catalogues: II - Photometric redshifts and rest-frame properties in Abell-2744 and MACS-J0416, Castellano et al. 2016

The full catalogues can be downloaded from this link http://www.astrodeep.eu/frontier-fields-download/ .

Original fits images for each survey

The table below gives links to the original fits images. They have been combined to create the HiPS that can be viewed in Aladin.

"N/A" in the table means that the corresponding fits image is not available.

Processed fits images

The table below gives links to the processed fits images. Processed images are the result of the procedure to subtract foreground light from ICL and bright cluster galaxies, as described in Merlin et al. 2016. They are displayed on a different scale with respect to the original images, to make faint sources more evident.

For parallel fields, the processed images are the same as the original images, but with different scale levels to see fainter sources. The original images for parallel fields are in the table above.

Description of the table columns

ID: Identication number in the input photometric catalogues. The IDs are organized as follows:

• H-detected objects have IDs starting from 1;
• IR-detected objects have IDs starting from 20000;
• the bright cluster objects, modeled and subtracted from the HST images, have IDs starting with 100000.

RA, DEC: Positions of objects.

MAG_…: AB magnitudes.

MAGERR_…: Relatives uncertainties for each magnitude.

ZBEST: Corresponds to the reference (median) photo-z value except when a match with a publicly available high-quality spectroscopic source is found within 1 arcsec. Sources for which the photo-z run did not converge to a solution are set to ZBEST=-1.0.

ZBEST_SIQR: Median photometric redshift uncertainty range (equal to 0 for spectroscopic sources).

MAGNIF: Median magnification (cluster fields), or magnification from the Merten model (parallel fields).

ZSPECFLAG: The value is set =1 for sources with spectroscopic redshift, =0 otherwise.

MSTAR: Stellar mass in units of 10⁹M_⊙ (assuming Salpeter IMF).

SFR: Star-formation rate in units of M_⊙/yr.

RELFLAG: This flag is meant to provide a combined indication of the robustness of photometric and photo-z estimates.

• Sources with RELFLAG=1 have enough reliable photometric information for estimating photometric-redshifts.
• Instead, the value is =0 for sources either:
  • falling close to the border of the images;
  • close to strong residual features of the Galfit image pre-processing;
  • found to be spurious (mostly stellar spikes) from visual inspection;
  • having SExtractor FLAG>=16;
  • having unphysical flux in the detection band;
  • having less than 5 HST bands with reliable flux measurement available for photo-z procedures.

How to view your catalogues

It is possible to add your own catalogues on the image in Aladin Lite. To do this, you must first upload your catalogue, in VOTable format, to the storage space at the CDS site, using the link "Upload your catalogues".

The best is done to automatically detect the columns of the file that contain the coordinates. If the selected colums for RA and dec are not the correct ones, you can choose the correct columns manually before sending the file to Aladin Lite.

With the "View your catalogues" button, you get a list of all your saved files. Use the checkbox to display the file in Aladin Lite. The color that appears near the checkbox is the color in which the sources are displayed in Aladin Lite.

If an error occurs during the loading of the file, this is indicated. The main reason for errors is that the file is not in the correct VOTable format.

Registering

You do not need to register to be able to upload tables in your storage space, but we do recommend to register as:

• Anonymous users are identified through a browser cookie. That means you will not be able to access your saved data from another computer (or even from another browser on the same computer). It also means that emptying your browser cache might remove the cookie, and you won't be able to access your saved data anymore.
• Registered users are identified through a login/password mechanism which allows them to access and retrieve their data from any computer.

Registering and login can be done by using the links at the top right of the main page.

More information

More information is available at the help page of the CDS Portal .

Contact

If you have any question about this site, you can send an email to cds-question@unistra.fr with the subject "Astrodeep portal".