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M. Vaccari C. Lari L. Angeretti D. Fadda C. Gruppioni F. Pozzi O. Prouton H. Aussel T. Babbedge P. Ciliegi A. Franceschini E. Gonzalez-Solares F. La Franca S. Oliver I. Perez-Fournon M. Rowan-Robinson S. Serjeant P. Väisänen 《Monthly notices of the Royal Astronomical Society》2005,358(2):397-418
We present the final analysis of the European Large Area Infrared Space Observatory ( ISO ) Survey (ELAIS) 15-μm observations, carried out with the ISO Camera (ISOCAM) instrument on board the ISO .
The data-reduction method, known as the Lari Method, is based on a mathematical model of the behaviour of the detector and was specifically designed for the detection of faint sources in ISOCAM/ISO Photopolarimeter (ISOPHOT) data. The method is fully interactive and leads to very reliable and complete source lists.
The resulting catalogue includes 1923 sources detected with signal-to-noise ratio of > 5 in the 0.5–100 mJy flux range and over an area of 10.85 deg2 split into four fields, making it the largest non-serendipitous extragalactic source catalogue obtained to date from the ISO data.
This paper presents the concepts underlying the data-reduction method together with its latest enhancements. The data-reduction process, the production and basic properties of the resulting catalogue are discussed. The catalogue quality is assessed by means of detailed simulations, optical identifications and comparison with previous analyses. 相似文献
The data-reduction method, known as the Lari Method, is based on a mathematical model of the behaviour of the detector and was specifically designed for the detection of faint sources in ISOCAM/ISO Photopolarimeter (ISOPHOT) data. The method is fully interactive and leads to very reliable and complete source lists.
The resulting catalogue includes 1923 sources detected with signal-to-noise ratio of > 5 in the 0.5–100 mJy flux range and over an area of 10.85 deg
This paper presents the concepts underlying the data-reduction method together with its latest enhancements. The data-reduction process, the production and basic properties of the resulting catalogue are discussed. The catalogue quality is assessed by means of detailed simulations, optical identifications and comparison with previous analyses. 相似文献
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Carlotta Gruppioni Seb Oliver Stephen Serjeant 《Astrophysics and Space Science》2001,276(2-4):791-798
We present new results on the nature of the faint radio galaxy population obtained from a deep identification study in the Marano Field. This work represents the highest identification fractions attained to date in literature for sub-mJy radio samples. Star-forming galaxies constitute a significant fraction of the optical counterparts of sub-mJy radio sources, although they are not the dominant identification class (as formerly believed). We also present a new determination of the co-moving star formation density from z=0 to z?0.35 using the radio luminosity function of star-forming galaxies. For the local determination, we used a sample of 231 spiral galaxies taken from the B≤12 Revised Shapley-Ames Catalogue, while for the non-local determination, we used a sample of87 star-forming galaxies taken from the Benn et al. (1993) sample. The inferred local star formation rate is about twice as great as the Hα estimate, while the intermediate 0.05<z<0.35 star formation rate is consistent with coeval ultraviolet and Hα estimates. This is due to large-scale structure, rarely accounted for in estimates of the cosmic star formation history; the situation could improve significantly with deep moderate-area radio surveys. 相似文献
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Carlotta Bonoli 《Astrophysics and Space Science》1983,89(2):377-385
Some remarks on the use of derivative spectroscopy in astronomy are considered. The advantages and the problems which arise with this technique are outlined. 相似文献
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Reproductive resilience of ice‐dependent Antarctic silverfish in a rapidly changing system along the Western Antarctic Peninsula 
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下载免费PDF全文 The Western Antarctic Peninsula (wAP) is globally one of the systems most heavily impacted by climate change, notably steep declines in sea ice extent. In forage species, reproductive resilience to change is particularly important because population fluctuations are rapidly communicated through the system via trophic interactions. The reproductive traits of the ice‐dependent forage species Antarctic silverfish (Pleuragramma antarctica) from different areas along the wAP and at the tip of the Antarctic Peninsula were investigated through macroscopic and histological analyses of gonads, with the aim to assess its reproductive potential and to test for spatial differences in fecundity and spawning season. Fish samples were collected in late summer off Charcot Island, in Marguerite Bay and off Joinville Island; no fish were caught in the central wAP. Samples from Charcot Island and Marguerite Bay consisted of adults in developing gonad stage, whereas those from Joinville consisted almost exclusively of juveniles. Mean GSI was relatively low (2–3%) and similar in both sexes, as specimens were still far from being actively reproducing. Developing females exhibited two discrete, though partially overlapping modes of oocytes of different size, with vitellogenic oocytes measuring 0.5–1.0 mm. Absolute and relative fecundity ranged between 3000 and 12,000 eggs per female and between 80 and 190 eggs·g?1, with a strong relationship between absolute fecundity and body size. These results were consistent with a single population at Charcot Island and Marguerite Bay and indicated substantial reproductive potential, which may mitigate population isolation and reductions in habitat availability but cannot ultimately offset catastrophic loss of spawning habitat linked to sea‐ice retreat. 相似文献
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C. Vignali F. Pozzi J. Fritz A. Comastri C. Gruppioni E. Bellocchi F. Fiore M. Brusa R. Maiolino M. Mignoli F. La Franca L. Pozzetti G. Zamorani A. Merloni 《Monthly notices of the Royal Astronomical Society》2009,395(4):2189-2195
We present multiwavelength observations (from optical to submillimetre, including Spitzer and Submillimetre Common-User Bolometer Array) of H2XMMJ 003357.2−120038 (also GD 158_19), an X-ray selected, luminous narrow-line (type 2) quasar at z = 1.957 selected from the HELLAS2XMM survey. Its broad-band properties can be reasonably well modelled assuming three components: a stellar component to account for the optical and near-infrared (IR) emission; an active galactic nucleus (AGN) component (i.e. dust heated by an accreting active nucleus), dominant in the mid-IR, with an optical depth at 9.7 along the line of sight (close to the equatorial plane of the obscuring matter) of τ(9.7) = 1 and a full covering angle of the reprocessing matter (torus) of 140° and a far-IR starburst component (i.e. dust heated by star formation) to reproduce the wide bump observed longward of 70 .
The derived star formation rate is ≈1500 M⊙ yr−1 . The overall modelling indicates that GD 158_19 is a high-redshift X-ray luminous, obscured quasar with coeval powerful AGN activity and intense star formation. It is probably caught before the process of expelling the obscuring gas has started, thus quenching the star formation. 相似文献
The derived star formation rate is ≈1500 M
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Paolo Ciliegi Carlotta Gruppioni Richard McMahon Michhael Rowan-Robinson 《Astrophysics and Space Science》2001,276(2-4):957-964
The optical identification programme is presented for a complete sample of 867 radio sources that were observed with the Very
Large Array (VLA) within 4.22 deg2 to S
1.4 GHz ≥ 0.135 mJy (5 σ). The area covered by the VLA survey is part of the regions of the sky that have been surveyed in the mid
and far Infrared over the wavelength range 6.7–175 μmwith ISO as part of the European Large Area ISO Survey (ELAIS). Optical
identifications are made using the Automatic Plate-measuring Machine (APM) optical catalogue in E (∼ R) and O (∼ B) bands with approximate limiting magnitudes of ∼ 20.0 and 21.5 mag, respectively. For 220 out of the 867 radio sources, likely
identifications are proposed with an a posteriori identification percentage of 25%. The sample of identification has a reliability
of 96% and a completeness of 80%.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Stephen Serjeant Bahram Mobasher † Carlotta Gruppioni Seb Oliver 《Monthly notices of the Royal Astronomical Society》2000,317(2):L29-L33
We present the first results of our Hubble Space Telescope HST WFPC2 F814W snapshot imaging survey, targeting virtually all sub-mJy decimetric radio-selected star-forming galaxies. The radio selection at ∼1 GHz is free from extinction effects and the radio luminosities are largely unaffected by AGN contamination, making these galaxies ideal tracers of the cosmic star formation history. A subsample of four targets is presented here, selected at 1.4 GHz from the spectroscopically homogenous and complete samples of Benn et al. and Hopkins et al. The redshifts are confined to a narrow range around z ∼0.2, to avoid differential evolution, with a radio luminosity close to L ∗ where the galaxies dominate the comoving volume-averaged star formation rate. We find clearly disturbed morphologies resembling those of ultraluminous infrared galaxies, indicating that galaxy interactions may be the dominant mechanism for triggering star formation at these epochs. The morphologies are also clearly different from those of coeval quasars and radio galaxies, as found in star-forming galaxies selected at other wavelengths. This may prove challenging for models that propose direct causal links between AGN evolution and the cosmic star formation history at these epochs. The asymmetries are typically much larger than seen in the Canada–France Redshift Survey at similar redshifts, optical luminosities and H α -derived star formation rates, indicating the possible existence of an obscuration-related morphological bias in such samples. 相似文献
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