Planck Collaboration: ERCSC the Cosmic Microwave Background (CMB)
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Astronomy & Astrophysics manuscript no. 16474ms c ESO 2011 August 15, 2011 Planck Early Results. VII. The Early Release Compact Source Catalogue Planck Collaboration: P. A. R. Ade76, N. Aghanim50, M. Arnaud63, M. Ashdown61,4, J. Aumont50, C. Baccigalupi74, A. Balbi30, A. J. Banday82,8,68, R. B. Barreiro57, J. G. Bartlett3,59, E. Battaner84, K. Benabed51, A. Benoˆıt49, J.-P. Bernard82,8, M. Bersanelli27,43, R. Bhatia5, A. Bonaldi39, L. Bonavera74,6, J. R. Bond7, J. Borrill67,78, F. R. Bouchet51, M. Bucher3, C. Burigana42, R. C. Butler42, P. Cabella30, C. M. Cantalupo67, B. Cappellini43, J.-F. Cardoso64,3,51, P. Carvalho4, A. Catalano3,62, L. Cay´on20, A. Challinor54,61,11, A. Chamballu47, R.-R. Chary48⋆, X. Chen48, L.-Y Chiang53, C. Chiang19, P. R. Christensen71,31, D. L. Clements47, S. Colombi51, F. Couchot66, A. Coulais62, B. P. Crill59,72, F. Cuttaia42, L. Danese74, R. J. Davis60, P. de Bernardis26, A. de Rosa42, G. de Zotti39,74, J. Delabrouille3, J.-M. Delouis51, F.-X. D´esert45, C. Dickinson60, J. M. Diego57, K. Dolag68, H. Dole50, S. Donzelli43,55, O. Dor´e59,9, U. D¨orl68, M. Douspis50, X. Dupac34, G. Efstathiou54, T. A. Enßlin68, H. K. Eriksen55, F. Finelli42, O. Forni82,8, P. Fosalba52, M. Frailis41, E. Franceschi42, S. Galeotta41, K. Ganga3,48, M. Giard82,8, Y. Giraud-H´eraud3, J. Gonz´alez-Nuevo74, K. M. G´orski59,86, S. Gratton61,54, A. Gregorio28, A. Gruppuso42, J. Haissinski66, F. K. Hansen55, D. Harrison54,61, G. Helou9, S. Henrot-Versill´e66, C. Hern´andez-Monteagudo68 , D. Herranz57, S. R. Hildebrandt9,65,56, E. Hivon51, M. Hobson4, W. A. Holmes59, A. Hornstrup13, W. Hovest68, R. J. Hoyland56,K.M. Huffenberger85, M. Huynh48,A.H. Jaffe47, W. C. Jones19, M. Juvela18, E. Keih¨anen18, R. Keskitalo59,18, T. S. Kisner67, R. Kneissl33,5, L. Knox22, H. Kurki-Suonio18,37, G. Lagache50, A. L¨ahteenm¨aki1,37, J.-M. Lamarre62, A. Lasenby4,61, R. J. Laureijs35, C. R. Lawrence59, S. Leach74, J. P. Leahy60, R. Leonardi34,35,23, J. Le´on-Tavares1, C. Leroy50,82,8, P. B. Lilje55,10, M. Linden-Vørnle13, M. L´opez-Caniego57, P. M. Lubin23, J. F. Mac´ıas-P´erez65, C. J. MacTavish61, B. Maffei60, G. Maggio41, D. Maino27,43, N. Mandolesi42, R. Mann75, M. Maris41, F. Marleau15, D. J. Marshall82,8, E. Mart´ınez-Gonz´alez57, S. Masi26, M. Massardi39, S. Matarrese25, F. Matthai68, P. Mazzotta30, P. McGehee48, P. R. Meinhold23, A. Melchiorri26, J.-B. Melin12, L. Mendes34, A. Mennella27,41, S. Mitra59, M.-A. Miville-Deschˆenes50,7, A. Moneti51, L. Montier82,8, G. Morgante42, D. Mortlock47, D. Munshi76,54, A. Murphy70, P. Naselsky71,31, P. Natoli29,2,42, C. B. Netterfield15, H. U. Nørgaard-Nielsen13, F. Noviello50, D. Novikov47, I. Novikov71, I. J. O’Dwyer59, S. Osborne80, F. Pajot50, R. Paladini79,9, B. Partridge36, F. Pasian41, G. Patanchon3, T. J. Pearson9,48, O. Perdereau66, L. Perotto65, F. Perrotta74, F. Piacentini26, M. Piat3,R. Piffaretti63,12, S. Plaszczynski66, P. Platania58, E. Pointecouteau82,8, G. Polenta2,40, N. Ponthieu50, T. Poutanen37,18,1, G. W. Pratt63, G. Pr´ezeau9,59, S. Prunet51, J.-L. Puget50, J. P. Rachen68, W. T. Reach83, R. Rebolo56,32, M. Reinecke68, C. Renault65, S. Ricciardi42, T. Riller68, I. Ristorcelli82,8, G. Rocha59,9, C. Rosset3, M. Rowan-Robinson47, J. A. Rubi˜no-Mart´ın56,32, B. Rusholme48, A. Sajina17, M. Sandri42, D. Santos65, G. Savini73, B. M. Schaefer81, D. Scott16, M. D. Seiffert59,9, P. Shellard11, G. F. Smoot21,67,3, J.-L. Starck63,12, F. Stivoli44, V. Stolyarov4, R. Sudiwala76, R. Sunyaev68,77, J.-F. Sygnet51, J. A. Tauber35, D. Tavagnacco41, L. Terenzi42, L. Toffolatti14, M. Tomasi27,43, J.-P. Torre50, M. Tristram66, J. Tuovinen69, M. T¨urler46, G. Umana38, L. Valenziano42, J. Valiviita55, J. Varis69, P. Vielva57, F. Villa42, N. Vittorio30, L. A. Wade59, B. D. Wandelt51,24, S. D. M. White68, A. Wilkinson60, D. Yvon12, A. Zacchei41, and A. Zonca23 (Affiliations can be found after the references) Preprint online version: August 15, 2011 ABSTRACT A brief description of the methodology of construction, contents and usage of the Planck Early Release Compact Source Catalogue (ERCSC), including the Early Cold Cores (ECC) and the Early Sunyaev-Zeldovich (ESZ) cluster catalogue is provided. The catalogue is based on data that consist of mapping the entire sky once and 60% of the sky a second time by Planck, thereby comprising the first high sensitivity radio/submillimetre observations of the entire sky. Four source detection algorithms were run as part of the ERCSC pipeline. A Monte-Carlo algorithm based on the injection and extraction of artificial sources into the Planck maps was implemented to select reliable sources among all extracted candidates such that the cumulative reliability of the catalogue is 90%. There is no requirement on completeness for the ERCSC. As a result of the Monte-Carlo assessment of reliability of sources from the diff≥erent techniques, an implementation of the PowellSnakes source extraction technique was used at the five frequencies between 30 and 143 GHz while the SExtractor technique was used between 217 and 857 GHz. The 10σ photometric flux density limit of the catalogue at b > 30◦ is 0.49, 1.0, 0.67, 0.5, 0.33, 0.28, 0.25, 0.47 and 0.82 Jy at each of the nine frequencies between 30 arXiv:1101.2041v2 [astro-ph.CO] 8 Jul 2011 and 857 GHz. Sources which are| up| to a factor of 2 fainter than this limit, and which are present in “clean” regions of the Galaxy where the sky background due to emission from the interstellar medium∼ is low, are included in the ERCSC if they meet the high reliability criterion. The Planck ERCSC sources have known associations to stars with dust shells, stellar cores, radio galaxies, blazars, infrared luminous galaxies and Galactic interstellar medium features. A significant fraction of unclassified sources are also present in the catalogs. In addition, two early release catalogs that contain 915 cold molecular cloud core candidates and 189 SZ cluster candidates that have been generated using multifrequency algorithms are presented. The entire source list, with more than 15000 unique sources, is ripe for follow-up characterisation with Herschel, ATCA, VLA, SOFIA, ALMA and other ground-based observing facilities. Key words. Cosmology:observations – Surveys – Catalogues – Radio continuum: general – Submillimetre: general 1. Introduction Planck1 (Tauber et al. 2010; Planck Collaboration 2011a) is the third-generation space mission to measure the anisotropy of ⋆ Corresponding Author: R.-R. Chary, [email protected] 1 Planck (http://www.esa.int/Planck) is a project of the European Space Agency (ESA) with instruments provided by two scientific con- 1 Planck Collaboration: ERCSC the cosmic microwave background (CMB). It observes the sky from the end of the first sky coverage to a community-wide re- in nine frequency bands covering 30–857GHz with high sen- lease of source lists is the motivating factor behind the reliability sitivity and angular resolution from 33arcmin to 4.2arcmin and flux-density accuracy requirements as well as the choice of (Table 1). The Low Frequency Instrument (LFI; Mandolesi et al. algorithms that were adopted for the ERCSC. 2010; Bersanelli et al. 2010; Mennella et al. 2011) covers the The sources of noise vary significantly as a function of lo- 30, 44, and 70GHz bands with amplifiers cooled to 20K. cation on the sky as well as a function of frequency. Apart from The High Frequency Instrument (HFI; Lamarre et al. 2010; the instrumental noise and the Galaxy, at the lowest frequencies Planck HFI Core Team 2011a) covers the 100, 143, 217, 353, the dominant astrophysical source of noise is the CMB itself. At 545, and 857GHz bands with bolometers cooled to 0.1K. the highest frequencies, zodiacal dust and emission from the in- Polarisation is measured in all but the highest two bands terstellar medium dominate. As a result, the flux density limits (Leahy et al. 2010; Rosset et al. 2010). A combination of radia- corresponding to the same reliability vary widely across the sky tive cooling and three mechanical coolers produces the temper- (Figure 1), with the sensitivity typically improving with increas- atures needed for the detectors and optics (Planck Collaboration ing ecliptic latitude. The areas of deepest coverage are centred 2011b). Two data processing centres (DPCs) check and cali- on the ecliptic pole regions due to the scan strategy and indi- brate the data and make maps of the sky (Planck HFI Core Team vidual sources in that vicinity may be observed several times by 2011b; Zacchei et al. 2011). Planck’s sensitivity, angular resolu- Planck in the course of a single sky survey. tion, and frequency coverage make it a powerful instrument for The data obtained from the scans of the sky between 2009 Galactic and extragalactic astrophysics as well as cosmology. August 13 and 2010 June 6, corresponding to Planck opera- Planck spins around its axis at a rate of one rotation per tional days 91–389, have been processed and converted into all- minute. The focal plane is oriented at an angle of 85◦ to sky maps at the HFI and LFI Data Processing Centres (DPCs). the satellite spin axis, which tracks the direction of the Sun The data extend beyond a single sky coverage with 60% of at 1◦ per day. The effective Planck scan strategy described the second sky coverage included in the maps. A descrip- in≈ Dupac& Tauber (2005) results in areas near the ecliptic tion of the processing can be found in Zaccheiet al. (2011); poles being observed several times more frequently than re- Planck HFI Core Team (2011b). Four different implementations gions of sky near the ecliptic plane.