The Herschel Multi-tiered Extragalactic Survey: SPIRE-mm photometric redshifts

Roseboom, I. G. and Ivison, R. J. and Greve, T. R. and Amblard, A. and Arumugam, V. and Auld, R. and Aussel, H. and Bethermin, M. and Blain, A. and Bock, J. and Boselli, A. and Brisbin, D. and Buat, V. and Burgarella, D. and Castro-Rodríguez, N. and Cava, A. and Chanial, P. and Chapin, E. and Chapman, S. and Clements, D. L. and Conley, A. and Conversi, L. and Cooray, A. and Dowell, C. D. and Dunlop, J. S. and Dwek, E. and Eales, S. and Elbaz, D. and Farrah, D. and Franceschini, A. and Glenn, J. and Griffin, M. and Halpern, M. and Hatziminaoglou, E. and Ibar, E. and Isaak, K. and Lagache, G. and Levenson, L. and Lu, N. and Madden, S. and Maffei, B. and Mainetti, G. and Marchetti, L. and Marsden, G. and Morrison, G. and Mortier, A. M. J. and Nguyen, H. T. and O'Halloran, B. and Oliver, S. J. and Omont, A. and Page, M. J. and Panuzzo, P. and Papageorgiou, A. and Pearson, C. P. and Pérez-Fournon, I. and Pohlen, M. and Rawlings, J. I. and Raymond, G. and Rigopoulou, D. and Rizzo, D. and Rodighiero, G. and Rowan-Robinson, M. and Schulz, B. and Scott, Douglas and Seymour, N. and Shupe, D. L. and Smith, A. J. and Stevens, J. A. and Symeonidis, M. and Trichas, M. and Tugwell, K. E. and Vaccari, M. and Valtchanov, I. and Vieira, J. D. and Viero, M. P. and Vigroux, L. and Wardlow, J. and Wang, L. and Wright, G. and Xu, C. K. and Zemcov, M. (2012) The Herschel Multi-tiered Extragalactic Survey: SPIRE-mm photometric redshifts. Monthly Notices of the Royal Astronomical Society, 419 (4). pp. 2758-2773. ISSN 0035-8711

Other (pdf)
1109.2887
Download (4kB)

Abstract

We investigate the potential of submm-mm and submm-mm-radio photometric redshifts using a sample of mm-selected sources as seen at 250, 350 and 500μm by the SPIRE instrument on Herschel. From a sample of 63 previously identified mm sources with reliable radio identifications in the Great Observatories Origins Deep Survey North and Lockman Hole North fields, 46 (73 per cent) are found to have detections in at least one SPIRE band. We explore the observed submm/mm colour evolution with redshift, finding that the colours of mm sources are adequately described by a modified blackbody with constant optical depth τ= (ν/nu0)β, where β=+1.8 and ν0=c/100 μm. We find a tight correlation between dust temperature and IR luminosity. Using a single model of the dust temperature and IR luminosity relation, we derive photometric redshift estimates for the 46 SPIRE-detected mm sources. Testing against the 22 sources with known spectroscopic or good quality optical/near-IR photometric redshifts, we find submm/mm photometric redshifts offer a redshift accuracy of |Δz|/(1 +z) = 0.16 (= 0.51). Including constraints from the radio-far-IR correlation, the accuracy is improved to |Δz|/(1 +z) = 0.15 (= 0.45). We estimate the redshift distribution of mm-selected sources finding a significant excess at z > 3 when compared to ˜ 850 μm selected samples.