Search Publications
Extragalactic background light inferred from AEGIS galaxy-SED-type fractions
Barmby, P.; Cooper, M. C.; Huang, J. -S. +15 more
The extragalactic background light (EBL) is of fundamental importance both for understanding the entire process of galaxy evolution and for γ-ray astronomy, but the overall spectrum of the EBL between 0.1 and 1000 µm has never been determined directly from galaxy spectral energy distribution (SED) observations over a wide redshift range. The…
Defining the intrinsic AGN infrared spectral energy distribution and measuring its contribution to the infrared output of composite galaxies
Alexander, D. M.; Hickox, R. C.; Mullaney, J. R. +1 more
We use infrared spectroscopy and photometry to empirically define the intrinsic mid- to far-infrared spectral energy distribution (i.e. 6-100 µm SED) of thermal emission produced by typical (i.e. 2-10 keV luminosity, L2-10 keV∼ 1042-1044 erg s-1) active galactic nuclei (hereafter AGNs). The average…
Effects of grain size distribution on the interstellar dust mass growth
Hirashita, Hiroyuki; Kuo, Tzu-Ming
Grain growth by the accretion of metals in interstellar clouds (called 'grain growth') could be one of the dominant processes that determine the dust content in galaxies. The importance of the grain size distribution for the grain growth is demonstrated in this paper. First, we derive an analytical formula that gives the grain size distribution af…
AzTEC/ASTE 1.1-mm survey of the AKARI Deep Field South: source catalogue and number counts
Yun, M. S.; Iono, D.; Khan, S. +20 more
We present results of a 1.1-mm deep survey of the AKARI Deep Field South (ADF-S) with AzTEC mounted on the Atacama Submillimetre Telescope Experiment (ASTE). We obtained a map of 0.25-deg2 area with an rms noise level of 0.32-0.71 mJy. This is one of the deepest and widest maps thus far at millimetre and submillimetre wavelengths. We un…
Luminosity functions of local infrared galaxies with AKARI: implications for the cosmic star formation history and AGN evolution
Goto, Tomotsugu; Inami, Hanae; Nakagawa, Takao +15 more
Infrared (IR) luminosity is fundamental to understanding the cosmic star formation history and active galactic nuclei (AGN) evolution, since their most intense stages are often obscured by dust. However, local IR luminosity function estimates today are still based on the IRAS survey in the 1980s, with wavelength coverage only up to 100 µm. T…
A serendipitous XMM survey of the SDSS: the evolution of the colour-magnitude diagram of X-ray AGN from z= 0.8 to 0.1
Nandra, K.; Georgakakis, Antonis
A new serendipitous XMM survey in the area of the Sloan Digital Sky Survey is described (XMM/SDSS), which includes features such as merging of overlapping fields to increase the sensitivity to faint sources, use of a new parametrization of the XMM point spread function for the source detection and photometry and an accurate estimation of the surve…
Spitzer spectra of evolved stars in ω Centauri and their low-metallicity dust production
van Loon, J. Th.; Gehrz, R. D.; Evans, A. +7 more
Dust production is explored around 14 metal-poor ([Fe/H]=-1.91 to -0.98) giant stars in the Galactic globular cluster ω Centauri using new Spitzer Infrared Spectrograph spectra. This sample includes the cluster's post-asymptotic giant branch (AGB) and carbon stars and is thus the first representative spectral study of dust production in a metal-po…
The microjansky and nanojansky radio sky: source population and multiwavelength properties
Padovani, Paolo
I present simple but robust estimates of the types of sources making up the faint, sub-microjansky radio sky. These include, not surprisingly, star-forming galaxies and radio-quiet active galactic nuclei but also two 'new' populations, i.e. low radio power ellipticals and dwarf galaxies, the latter likely constituting the most numerous component o…
Ice chemistry in massive young stellar objects: the role of metallicity
van Loon, J. Th.; Indebetouw, R.; Tielens, A. G. G. M. +6 more
We present the comparison of the three most important ice constituents (water, CO and CO2) in the envelopes of massive young stellar objects (YSOs), in environments of different metallicities: the Galaxy, the Large Magellanic Cloud (LMC) and, for the first time, the Small Magellanic Cloud (SMC). We present observations of water, CO and …
Infrared luminosity functions of AKARI Sloan Digital Sky Survey galaxies
Goto, Tomotsugu; Inami, Hanae; Nakagawa, Takao +16 more
By cross-correlating the AKARI all-sky survey in six infrared (IR) bands (9, 18, 65, 90, 140 and 160 µm) with the Sloan Digital Sky Survey (SDSS) galaxies, we identified 2357 IR galaxies with a spectroscopic redshift. This is not just one of the largest samples of local IR galaxies, but AKARI provides crucial far-IR (FIR) bands for accuratel…