Browsing by Author "Blain, A."
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- HerMES: a deficit in the surface brightness of the cosmic infrared background due to galaxy cluster gravitational lensingZemcov, M.; Blain, A.; Cooray, A.; Bethermin, M.; Bock, J.; Clements, D. L.; Conley, A.; Conversi, L.; Dowell, C. D.; Farrah, D.; Glenn, J.; Griffin, M.; Halpern, M.; Jullo, E.; Kneib, J. P.; Marsden, G.; Nguyen, H. T.; Oliver, S. J.; Richard, J.; Roseboom, I. G.; Schulz, B.; Scott, D.; Shupe, D. L.; Smith, A. J.; Valtchanov, I.; Viero, M.; Wang, L.; Wardlow, J. (IOP Publishing Ltd., 2013-06)We have observed four massive galaxy clusters with the SPIRE instrument on the Herschel Space Observatory and measure a deficit of surface brightness within their central region after removing detected sources. We simulate the effects of instrumental sensitivity and resolution, the source population, and the lensing effect of the clusters to estimate the shape and amplitude of the deficit. The amplitude of the central deficit is a strong function of the surface density and flux distribution of the background sources. We find that for the current best fitting faint end number counts, and excellent lensing models, the most likely amplitude of the central deficit is the full intensity of the cosmic infrared background (CIB). Our measurement leads to a lower limit to the integrated total intensity of the CIB of I-250 mu m > 0.69(-0.03)(+0.03)(stat.)(-0.06)(+0.11)(sys.) MJy sr(-1), with more CIB possible from both low-redshift sources and from sources within the target clusters. It should be possible to observe this effect in existing high angular resolution data at other wavelengths where the CIB is bright, which would allow tests of models of the faint source component of the CIB.
- A New Population of High-z, Dusty Lyα Emitters and Blobs Discovered by WISE: Feedback Caught in the Act?Bridge, C. R.; Blain, A.; Borys, C. J. K.; Petty, S.; Benford, D.; Eisenhardt, P.; Farrah, D.; Griffith, R. L.; Jarrett, T.; Lonsdale, C.; Stanford, S. A.; Stern, D.; Tsai, C. W.; Wright, E. L.; Wu, J. W. (IOP PUBLISHING LTD, 2013-06)By combining data from the NASA Wide-field Infrared Survey Explorer (WISE) mission with optical spectroscopy from the W. M. Keck telescope, we discover a mid-IR color criterion that yields a 78% success rate in identifying rare, typically radio-quiet, 1.6 less than or similar to z less than or similar to 4.6 dusty Ly alpha emitters (LAEs). Of these, at least 37% have emission extended on scales of 30-100 kpc and are considered Ly alpha "blobs" (LABs). The objects have a surface density of only similar to 0.1 deg(-2), making them rare enough that they have been largely missed in deep, small area surveys. We measured spectroscopic redshifts for 92 of these galaxies, and find that the LAEs (LABs) have a median redshift of 2.3 (2.5). The WISE photometry coupled with data from Herschel (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) reveals that these galaxies are in the Hyper Luminous IR galaxy regime (L-IR greater than or similar to 10(13)-10(14) L-circle dot) and have warm colors. They are typically more luminous and warmer than other dusty, z similar to 2 populations such as submillimeter-selected galaxies and dust-obscured galaxies. These traits are commonly associated with the dust being illuminated by intense active galactic nucleus activity. We hypothesize that the combination of spatially extended Ly alpha, large amounts of warm IR-luminous dust, and rarity (implying a short-lived phase) can be explained if the galaxies are undergoing brief, intense "feedback" transforming them from an extreme dusty starburst/QSO into a mature galaxy.