J/A+A/342/313 ISO HDF observations from PRETI method (Aussel+, 1999)
Provisional ISOCAM observations of the Hubble Deep Field reduced
with the PRETI method
Aussel H., Cesarsky C.J., Elbaz D., Starck J.L.
<Astron. Astrophys. 342, 313 (1999)>
=1999A&A...342..313A 1999A&A...342..313A
ADC_Keywords: Infrared sources ; Surveys
Mission_Name: ISO
Keywords: infrared: galaxies - galaxies: evolution - methods: data analysis
Abstract:
We have developed a new ISOCAM data reduction technique based on
wavelet analysis, especially designed for the detection of faint
sources in mid-infrared surveys. This method, the Pattern REcognition
Technique for Isocam data (PRETI) has been used to reduce the
observations of the Hubble Deep Field (HDF) and flanking fields with
ISOCAM at 6.75 (LW2) and 15µm (LW3) (Rowan-Robinson et al.
1997MNRAS.289..490R 1997MNRAS.289..490R). Simulations of ISOCAM data allow us to test the
photometric accuracy and completeness of the reduction. According to
these simulations, the PRETI source list is 95% complete in the
15µm band at 200µJy and in the 6.75µm band at 65µJy, using
detection thresholds which minimize the number of false detections. We
detect 49 objects in the ISO-HDF at high confidence secure level, 42
in the LW3 filter, 3 in the LW2 filter, and 4 in both filters. An
additional, less secure, list of 100 sources is presented, of which 89
are detected at 15µm only, 7 at 6.75µm only and 4 in both
filters. All ISO-HDF objects detected in the HDF itself have optical
or infrared counterparts, except for one from the additional list. All
except one of the radio sources detected in the field by Fomalont et
al. (1997ApJ...475L...5F 1997ApJ...475L...5F) are detected with ISOCAM. Using a precise
correction for the field of view distortion of ISOCAM allows us to
separate blended sources. This, together with the fact that PRETI
allows to correct data on the tail of cosmic rays glitches, lead us to
produce deeper source lists than previous authors. Our list of bright
sources agree with those of Desert et al. (1999A&A...342..363D 1999A&A...342..363D) in
both filters, and with those of Goldschmidt et al. (1997MNRAS.289..465G 1997MNRAS.289..465G)
in the LW3 filter, with systematic difference in photometry.
ISO is an ESA project with instruments funded by ESA Member States
(especially the PI countries: France, Germany, The Netherlands and the
United Kingdom) and with participation of ISAS and NASA.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
isocat.dat 54 100 Provisional PRETI catalogue
7um.dat 43 100 7µm data
15um.dat 43 100 15µm data
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See also:
B/iso : ISO Observation Log of validated data (ISO Data Centre, 2001)
Byte-by-byte Description of file: isocat.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- ID Catalogue ID. (1)
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 22 F4.1 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 32 I2 arcsec DEs Arcsecond of Declination (J2000)
34 A1 --- l_7um 6.7 micron flux is upper limit
35- 37 I3 uJy 7um ? 6.7 micron flux in 3 arcmin aperture
39- 40 I2 uJy E_7um ? Upper error bound to 6.7 micron flux
42- 43 I2 uJy e_7um ? Lower error bound to 6.7 micron flux
45 A1 --- l_15um 15 micron flux is upper limit
46- 48 I3 uJy 15um 15 micron flux in 6 arcsec aperture
50- 51 I2 uJy E_15um ? Upper error bound to 15 micron flux
53- 54 I2 uJy e_15um ? Lower error bound to 15 micron flux
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Note (1): the ID starts by
HDF_PM2 = detection at 6.5µm at above 7 times noise level
in wavelet space
HDF_PM3 = detection at 15µmat at above 7 times noise level
in wavelet space
HDF_PS2 = detection at 6.5µm at above 5 times noise level
in wavelet space
HDF_PS3 = detection at 15µm at above 3 times noise level
in wavelet space
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Byte-by-byte Description of file: 7um.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- ID Catalogue ID. (1)
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 22 F4.1 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 32 I2 arcsec DEs Arcsecond of Declination (J2000)
34 A1 --- l_7um 6.7 micron flux is upper limit
35- 37 I3 uJy 7um ? 6.7 micron flux in 3 arcmin aperture
39- 40 I2 uJy E_7um ? Upper error bound to 6.7 micron flux
42- 43 I2 uJy e_7um ? Lower error bound to 6.7 micron flux
--------------------------------------------------------------------------------
Note (1): the ID starts by
HDF_PM2 = detection at 6.5µm at above 7 times noise level
in wavelet space
HDF_PM3 = detection at 15µmat at above 7 times noise level
in wavelet space
HDF_PS2 = detection at 6.5µm at above 5 times noise level
in wavelet space
HDF_PS3 = detection at 15µm at above 3 times noise level
in wavelet space
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Byte-by-byte Description of file: 15um.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- ID Catalogue ID. (1)
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 22 F4.1 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 32 I2 arcsec DEs Arcsecond of Declination (J2000)
34 A1 --- l_15um 15 micron flux is upper limit
35- 37 I3 uJy 15um 15 micron flux in 6 arcsec aperture
39- 40 I2 uJy E_15um ? Upper error bound to 15 micron flux
42- 43 I2 uJy e_15um ? Lower error bound to 15 micron flux
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Note (1): the ID starts by
HDF_PM2 = detection at 6.5µm at above 7 times noise level
in wavelet space
HDF_PM3 = detection at 15µmat at above 7 times noise level
in wavelet space
HDF_PS2 = detection at 6.5µm at above 5 times noise level
in wavelet space
HDF_PS3 = detection at 15µm at above 3 times noise level
in wavelet space
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History:
Entered by A Richards (Jodrell Bank Observatory)
(End) A Richards [Jodrell Bank] 20-Dec-2002