J/A+A/621/A133 ABYSS HUDF WFC3 IR mosaics (Borlaff+, 2019)
The missing light of the Hubble Ultra Deep Field.
Borlaff A., Trujillo I., Roman J., Beckman J.E., Eliche-Moral M.C.,
Infante-Sainz R., Lumbreras A., Sato Martin de Almagro R.T.,
Gomez-Guijarro C., Cebrian M., Dorta A., Cardiel N., Akhlaghi M.,
Martinez-Lombilla C.
<Astron. Astrophys. 621, A133 (2019)>
=2019A&A...621A.133B 2019A&A...621A.133B (SIMBAD/NED BibCode)
ADC_Keywords: Combined data ; Galaxies, photometry ; Photometry, infrared ;
Space observations
Keywords: techniques: image processing - techniques: photometric -
methods: observational - galaxies: evolution - galaxies: structure -
galaxies: high-redshift
Abstract:
The Hubble Ultra Deep field (HUDF) is the deepest region ever observed
with the Hubble Space Telescope. With the main objective of unveiling
the nature of galaxies up to z∼7-8, the observing and reduction
strategy have focused on the properties of small and unresolved
objects, rather than the outskirts of the largest objects, which are
usually over-subtracted.
We aim to create a new set of WFC3 IR mosaics of the HUDF using novel
techniques to preserve the properties of the low surface brightness
regions.
We created ABYSS a pipeline that optimises the estimate and modelling
of low-level systematic effects to obtain a robust background
subtraction. We have improved four key points in the reduction: 1)
creation of new absolute sky flat fields, 2) extended persistence
models, 3) dedicated sky background subtraction and 4) robust
co-adding.
The new mosaics successfully recover the low surface brightness
structure removed on the previous HUDF published reductions. The
amount of light recovered with a mean surface brightness dimmer than
mu=26mag/arcsec2 is equivalent to a m=19 mag source when compared
to the XDF and a m=20mag compared to the HUDF12.
We present a set of techniques to reduce ultra-deep images
(mu>32.5mag/arcsec2, 3 sigma in 10x10 arcsec boxes), that
successfully allow to detect the low surface brightness structure of
extended sources on ultra deep surveys. The developed procedures are
applicable to HST, JWST, EUCLID and many other space and ground-based
observatories. We made the final ABYSS WFC3 IR HUDF mosaics publicly
available at http://www.iac.es/proyecto/abyss/.
Description:
These are the ABYSS HUDF WFC3/IR mosaics which have been created by
Alejandro Borlaff as part of the ABYSS working team at the Instituto
de Astrofisica de Canarias (IAC),
http://www.iac.es/proyecto/abyss/
The main objective of the ABYSS project is to explore the Low Surface
Brightness capabilities of HST, creating a dedicated version of the
HUDF for the study of the low surface brightness regions of the most
extended sources. In order to do that, we revised and reprocessed the
HST data presented on the eXtreme deep field (XDF, Illingworth et. al
2013), HUDF12 (Koekemoer et al. 2012) and HUDF09 (Bouwens et al.
2009).
Each fits file contains 4 extensions
-----
Column 1: Index (counting from 0, usable with `--hdu').
Column 2: Name (`EXTNAME' in FITS standard, usable with `--hdu').
Column 3: Image data type or `table' format (ASCII or binary).
Column 4: Size of data in HDU.
-----
EXT 0 n/a uint8 0
EXT 1 INPUT-NO-SKY float32 2809x2856
EXT 2 +1 sigma error float64 2809x2856
EXT 3 -1 sigma error float64 2809x2856
The detailed description of the methods used for the creation of these
dedicated low surface brightness mosaics is fully available in the
paper.
Objects:
--------------------------------------------------------------
RA (2000) DE Designation(s)
--------------------------------------------------------------
03 32 39.0 -27 47 29 HUDF = NAME Hubble Ultra Deep Field
--------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 72 4 List of fits images
fits/* . 4 Individual fits images
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See also:
J/ApJ/780/34 : H160-selected catalog of galaxies in the HUDF (Lundgren+, 2014)
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 34 I5 Kibyte size Size of FITS file
36- 48 A13 --- FileName Name of FITS file, in subdirectory fits
50- 72 A23 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Alejandro Borlaff, asborlaff(at)ucm.es
(End) Patricia Vannier [CDS] 25-Dec-2018