Faint source detection in ISOCAM images

Starck, Jean-Luc; Aussel, H.; Elbaz, D.; Fadda, D.; Césarsky, C. J.

doi:10.1051/aas:1999281

Cited by 42 publications

(37 citation statements)

References 13 publications

(19 reference statements)

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“…The Pattern Recognition Technique for ISOCAM data (PRETI) by Starck et al (1999) decomposes the signal at different time scales and models the parts of the signal below and over the median level. Then, it recognizes patterns which are similar to sources and subtract the other parts from the original signal.…”

Section: The Methodsmentioning

confidence: 99%

ISOCAM observations in the Lockman Hole

Fadda

Lari

Rodighiero

et al. 2004

A&A

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Abstract. We present the image and catalogue of the 14.3 µm shallow survey of 0.55 square degrees in the region of the Lockman Hole (10 h 52 m 03 s +57 o 21 46 , J2000) with the Infrared Space Observatory (ISO). The data have been analyzed with the recent algorithm by Lari et al. (2001, MNRAS, 325, 1173 conceived to exploit ISO data in an optimal way, especially in the case of shallow surveys with low redundancy. Photometry has been accurately evaluated through extensive simulations and also the absolute calibration has been checked using a set of 21 stars detected at 14.3 µm, optical, and near-IR bands. On the basis of simulations, we evaluate that the survey is 80%, 50%, and 20% complete at 0.8, 0.6, and 0.45 mJy, respectively. Below the 20% completeness limit, fluxes are generally overestimated since the sources are preferentially detected if their positions correspond to positive oscillations of the noise. Moreover, from a comparison with the deep survey, we estimate that only sources brighter than 0.45 mJy are highly reliable. Only 5% of these sources do not have optical counterparts down to r = 25. Since none of the Spitzer imaging bands cover the 14.3 µm wavelength range, this data set will remain unique until the advent of the James Webb Space Telescope.

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Section: The Methodsmentioning

confidence: 99%

ISOCAM observations in the Lockman Hole

Fadda

Lari

Rodighiero

et al. 2004

A&A

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“…Lémonon et al (1998) reported results obtained from a shallower raster over A2390. Both groups used the reduction method called PRETI, described in Starck et al (1999). Barvainis et al (1999) reported CAM photometry of sources in the field of Abell 2218.…”

Section: Figmentioning

confidence: 99%

“…Methods and applications of ISOCAM data analysis directed at the extraction of the faintest sources have been described by Lari et al (2001), Starck et al (1999), Aussel et al (1999a) and Elbaz et al (1998).…”

Section: General Remarksmentioning

confidence: 99%

K$_{\mbox{\fontsize{12pt}{14pt}\selectfont{\textit{s}}}}$-band luminosity function of thez= 1.237 cluster of galaxies RDCS J1252.9-2927

Toft¹,

Mainieri²,

Rosati³

et al. 2004

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Abstract. ESA's Infrared Space Observatory (ISO) was used to perform a deep survey with ISOCAM through three massive gravitationally lensing clusters of galaxies. The total area surveyed depends on source flux, with nearly seventy square arcminutes covered for the brighter flux levels in maps centred on the three clusters Abell 370, Abell 2218 and Abell 2390. We present maps and photometry at 6.7 µm (hereafter 7 µm) and 14.3 µm (hereafter 15 µm), showing a total of 145 mid-infrared sources and the associated source counts. At 15 µm these counts reach the faintest level yet recorded. Almost all of the sources have been confirmed on more than one infrared map and all are identified with counterparts in the optical or near-infrared. Detailed models of the three clusters have been used to correct for the effects of gravitational lensing on the background source population. Lensing by the clusters increases the sensitivity of the survey, and the weakest sources have lensing corrected fluxes of 5 and 18 µJy at 7 and 15 µm, respectively. Roughly 70% of the 15 µm sources are lensed background galaxies. Of sources detected only at 7 µm, 95% are cluster galaxies for this sample. Of fifteen SCUBA sources within the mapped regions of the three clusters seven were detected at 15 microns. The redshifts for five of these sources lie in the range 0.23 to 2.8, with a median value of 0.9. Flux selected subsets of the field sources above the 80% and 50% completeness limits were used to derive source counts to a lensing corrected sensitivity level of 30 µJy at 15 µm, and 14 µJy at 7 µm. The source counts, corrected for the effects of completeness, contamination by cluster sources and lensing, confirm and extend earlier findings of an excess by a factor of ten in the 15 µm population with respect to source models with no evolution. The observed mid-infrared field sources occur mostly at redshifts between 0.4 and 1.5. For the counts at 7 µm, integrating in the range 14 µJy to 460 µJy, we resolve (0.49± 0.2)×10 −9 W m −2 sr −1 of the infrared background light into discrete sources. At 15 µm we include the counts from other extensive ISOCAM surveys to integrate over the range 30 µJy to 50 mJy, reaching two to three times deeper than the unlensed surveys to resolve (2.7 ± 0.62) × 10 −9 W m −2 sr −1 of the infrared background light. These values correspond to 10% and 55%, respectively, of the upper limit to the infrared background light, derived from photon-photon pair production of the high energy gamma rays from BL-Lac sources on the infrared background photons. However, the recent detections of TeV gamma rays from the z = 0.129 BL Lac H1426+428 suggest that the value for the 15 µm background reported here is already sufficient to imply substantial absorption of TeV gamma rays from that source.Key words. surveys -galaxies: clusters: individual: Abell 370 -galaxies: clusters: individual: Abell 2218 -galaxies: clusters: individual: Abell 2390 -gravitational lensing -infrared: galaxiesSend offprint requests to: L. Metcalfe, e-mail: lmetca...

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“…Wavelet decomposition, e.g. for ISOCAM by Starck et al (1999), is not easily implementable because of the poor spatial dynamics of our maps ("big pixels and small maps"). To overcome these difficulties we have developed the following method by combining some well-known techniques for source extraction and flux determination:…”

Section: Source Extractionmentioning

confidence: 99%

FIRBACK: III. Catalog, source counts, and cosmological implications of the 170μm ISO deep survey

Dole

Gispert

Lagache

et al. 2001

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Abstract. The FIRBACK (Far Infrared BACKground) survey is one of the deepest imaging surveys carried out at 170 µm with ISOPHOT onboard ISO, and is aimed at the study of the structure of the Cosmic Far Infrared Background. This paper provides the analysis of resolved sources. After a validated process of data reduction and calibration, we perform intensive simulations to optimize the source extraction, measure the confusion noise (σc = 45 mJy), and give the photometric and astrometric accuracies. 196 galaxies with flux S > 3σc are detected in the area of 3.89 square degrees. Counts of sources with flux S > 4σc present a steep slope of 3.3 ± 0.6 on a differential "log N-log S" plot between 180 and 500 mJy. As a consequence, the confusion level is high and will impact dramatically on future IR deep surveys. This strong evolution, compared with a slope of 2.5 from Euclidian geometry, is in line with models implying a strongly evolving Luminous Infrared Galaxy population. The resolved sources account for less than 10% of the Cosmic Infrared Background at 170 µm, which is expected to be resolved into sources in the 1 to 10 mJy range.Key words. cosmology: miscellaneous -galaxies: infrared -galaxies: evolution -galaxies: statistics Send offprint requests to: H. Dole, e-mail: hdole@as.arizona.edu Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, The Netherlands and the UK) and with the participation of ISAS and NASA.Tables 7 to 13 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via

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Faint source detection in ISOCAM images

Cited by 42 publications

References 13 publications

ISOCAM observations in the Lockman Hole

ISOCAM observations in the Lockman Hole

K$_{\mbox{\fontsize{12pt}{14pt}\selectfont{\textit{s}}}}$-band luminosity function of thez= 1.237 cluster of galaxies RDCS J1252.9-2927

FIRBACK: III. Catalog, source counts, and cosmological implications of the 170μm ISO deep survey

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