Dust-obscured star formation in the outskirts of XMMU J2235.3-2557, a massive galaxy cluster at z=1.4

20Star formation (SF) in the galaxy populations of local massive clusters is reduced with respect to field galaxies, and tends to be suppressed in the core region. Indications of a reversal of the SF-density relation have been observed in a few z > 1.4 clusters. Using deep imaging from 100-500 mu m from Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging REceiver (SPIRE) onboard Herschel, we investigate infrared properties of spectroscopic and photo-z cluster members, and of H alpha emitters in XMMU J2235.3-2557, one of the most massive, distant, X-ray selected clusters known. Our analysis is based mostly on fitting of the galaxies spectral energy distribution (SED) in the rest-frame 8-1000 mu m. We measure total IR luminosity, deriving star formation rates (SFRs) ranging from 89 to 463 M-circle dot yr(-1) for 13 galaxies individually detected by Herschel, all located beyond the core region (r > 250 kpc). We perform a stacking analysis of nine star-forming members not detected by PACS, yielding a detection with SFR = 48 +/- 16 M-circle dot yr(-1). Using a colour criterion based on a star-forming galaxy SED at the cluster redshift, we select 41 PACS sources as candidate star-forming cluster members. We characterize a population of highly obscured SF galaxies in the outskirts of XMMU J2235.3-2557. We do not find evidence for a reversal of the SF-density relation in this massive, distant cluster.nonenoneSantos JS; Altieri B; Popesso P; Strazzullo V; Valtchanov I; Berta S; Bohringer H; Conversi L; Demarco R; Edge AC; Lidman C; Lutz D; Metcalfe L; Mullis CR; Pintos-Castro I; Sanchez-Portal M; Rawle TD; Rosati P; Swinbank AM; Tanaka MSantos, Js; Altieri, B; Popesso, P; Strazzullo, V; Valtchanov, I; Berta, S; Bohringer, H; Conversi, L; Demarco, R; Edge, Ac; Lidman, C; Lutz, D; Metcalfe, L; Mullis, Cr; Pintos-Castro, I; Sanchez-Portal, M; Rawle, Td; Rosati, P; Swinbank, Am; Tanaka,