P. Chanial

GOODS–Herschel: an infrared main sequence for star-forming galaxies

We present the deepest 100 to 500u2009μm far-infrared observations obtained with the Herschel Space Observatory as part of the GOODS-Herschel key program, and examine the infrared (IR) 3–500u2009μm spectral energy distributions (SEDs) of galaxies at 0 < z < 2.5, supplemented by a local reference sample from IRAS, ISO, Spitzer, and AKARI data. We determine the projected star formation densities of local galaxies from their radio and mid-IR continuum sizes. nWe find that the ratio of total IR luminosity to rest-frame 8u2009μm luminosity, IR8 (≡ L_(IR)^(tot)/L_8), follows a Gaussian distribution centered on IR8 = 4 (σ = 1.6) and defines an IR main sequence for star-forming galaxies independent of redshift and luminosity. Outliers from this main sequence produce a tail skewed toward higher values of IR8. This minority population ( u20093 × 10^(10) L_⊙u2009kpc^(-2)) and a high specific star formation rate (i.e., starbursts). The rest-frame, UV-2700u2009A size of these distant starbursts is typically half that of main sequence galaxies, supporting the correlation between star formation density and starburst activity that is measured for the local sample. nLocally, luminous and ultraluminous IR galaxies, (U)LIRGs (L_(IR)^(tot)≥ 10^(11) L_☉), are systematically in the starburst mode, whereas most distant (U)LIRGs form stars in the “normal” main sequence mode. This confusion between two modes of star formation is the cause of the so-called “mid-IR excess” population of galaxies found at z > 1.5 by previous studies. Main sequence galaxies have strong polycyclic aromatic hydrocarbon (PAH) emission line features, a broad far-IR bump resulting from a combination of dust temperatures (T_(dust)u2009~u200915–50 K), and an effective T_(dust)u2009 ~u200931 K, as derived from the peak wavelength of their infrared SED. Galaxies in the starburst regime instead exhibit weak PAH equivalent widths and a sharper far-IR bump with an effective T_(dust)~u200940 K. Finally, we present evidence that the mid-to-far IR emission of X-ray active galactic nuclei (AGN) is predominantly produced by star formation and that candidate dusty AGNs with a power-law emission in the mid-IR systematically occur in compact, dusty starbursts. After correcting for the effect of starbursts on IR8, we identify new candidates for extremely obscured AGNs.

The Herschel Space Observatory view of dust in M81

We use Herschel Space Observatory data to place observational constraints on the peak and Rayleigh-Jeans slope of dust emission observed at 70–500 μm in the nearby spiral galaxy M81. We find that the ratios of wave bands between 160 and 500 μm are primarily dependent on radius but that the ratio of 70 to 160 μm emission shows no clear dependence on surface brightness or radius. These results along with analyses of the spectral energy distributions imply that the 160–500 μm emission traces 15–30 K dust heated by evolved stars in the bulge and disc whereas the 70 μm emission includes dust heated by the active galactic nucleus and young stars in star forming regions.

HerMES: point source catalogues from deep Herschel-SPIRE observations

We describe the generation of single-band point source catalogues from submillimetre Herschel-SPIRE observations taken as part of the Science Demonstration Phase of the Herschel Multi-tiered Extragalactic Survey (HerMES). Flux densities are found by means of peak finding and the fitting of a Gaussian point-response function. With highly confused images, careful checks must be made on the completeness and flux-density accuracy of the detected sources. This is done by injecting artificial sources into the images and analysing the resulting catalogues. Measured flux densities at which 50 per cent of injected sources result in good detections at (250, 350 and 500) mu m range from (11.6, 13.2 and 13.1) to (25.7, 27.1 and 35.8) mJy, depending on the depth of the observation (where a good detection is taken to be one with positional offset less than one full-width half-maximum of the point-response function, and with the measured flux density within a factor of 2 of the flux density of the injected source). This paper acts as a reference for the 2010 July HerMES public data release.

Discovery of a Multiply Lensed Submillimeter Galaxy in Early HerMES Herschel/SPIRE Data

We report the discovery of a bright (

Herschel-SPIRE, far-infrared properties of millimetre-bright and -faint radio galaxies

f(250mum) > 400

Herschel/HerMES: The X-ray-infrared correlation for star-forming galaxies at z~1

mJy), multiply-lensed submillimeter galaxy obj in {it Herschel}/SPIRE Science Demonstration Phase data from the HerMES project. Interferometric 880mum Submillimeter Array observations resolve at least four images with a large separation of

Formation of the compact jets in the black hole GX 339−4

sim 9arcsec

Dynamical Structure of the Molecular Interstellar Medium in an Extremely Bright, Multiply Lensed z 3 Submillimeter Galaxy Discovered with Herschel

. A high-resolution adaptive optics

Redshift determination and co line excitation modeling for the multiply lensed galaxy hlsw-01

K_p

The JCMT Nearby Galaxies Legacy Survey – VIII. CO data and the LCO(3-2)–LFIR correlation in the SINGS sample

image with Keck/NIRC2 clearly shows strong lensing arcs. Follow-up spectroscopy gives a redshift of