Aims. We aim to demonstrate that the Herschel-ATLAS (H-ATLAS) is suitable for a blind and unbiased survey for debris disks by identifying candidate debris disks associated with main sequence stars in ...the initial science demonstration field of the survey. We show that H-ATLAS reveals a population of far-infrared/sub-mm sources that are associated with stars or star-like objects on the SDSS main-sequence locus. We validate our approach by comparing the properties of the most likely candidate disks to those of the known population. Methods. We use a photometric selection technique to identify main sequence stars in the SDSS DR7 catalogue and a Bayesian Likelihood Ratio method to identify H-ATLAS catalogue sources associated with these main sequence stars. Following this photometric selection we apply distance cuts to identify the most likely candidate debris disks and rule out the presence of contaminating galaxies using UKIDSS LAS K-band images. Results. We identify 78 H-ATLAS sources associated with SDSS point sources on the main-sequence locus, of which two are the most likely debris disk candidates: H-ATLAS J090315.8 and H-ATLAS J090240.2. We show that they are plausible candidates by comparing their properties to the known population of debris disks. Our initial results indicate that bright debris disks are rare, with only 2 candidates identified in a search sample of 851 stars. We also show that H-ATLAS can derive useful upper limits for debris disks associated with Hipparcos stars in the field and outline the future prospects for our debris disk search programme.
We report on a search for the optical counterparts of 175-μm selected sources from the Far-Infrared Background (FIRBACK) survey in the European Large Area ISO Survey (ELAIS) N2 field. Applying a ...likelihood ratio technique to optical catalogues from the Isaac Newton Telescope — Wide Field Survey (INT-WFS), we found optical identifications for 33 out of 55 FIRBACK sources in this field. These were then reassessed in the light of associations with the ELAIS final catalogue for the N2 field, to yield a final set of 31 associations. We have investigated the nature of this population through a comparison of their observed spectral energy distributions (SEDs) with predictions from radiative transfer models which simulate the emission from both cirrus and starburst components. We find the far-infrared sources to be 80 per cent starburst galaxies with their starburst component at a high optical depth. The resulting SEDs were used to estimate far-infrared luminosities, star formation rates (SFRs), dust temperatures and dust masses. The N2 FIRBACK population is found to consist of four suspected ultraluminous infrared galaxies (ULIRGs) with LFIR∼ 1012 L⊙ and SFRFIR > 100 M⊙ yr−1, a number of luminous infrared galaxies (LIRGs) with moderate star formation rates and LFIR∼ 1011 L⊙ and a population of low-redshift quiescently star-forming galaxies. We also discuss the implications of these results for current evolutionary models.
The heterogeneity of breast cancer plays a major role in drug response and resistance and has been extensively characterized at the genomic level. Here, a single-cell breast cancer mass cytometry ...(BCMC) panel is optimized to identify cell phenotypes and their oncogenic signalling states in a biobank of patient-derived tumour xenograft (PDTX) models representing the diversity of human breast cancer. The BCMC panel identifies 13 cellular phenotypes (11 human and 2 murine), associated with both breast cancer subtypes and specific genomic features. Pre-treatment cellular phenotypic composition is a determinant of response to anticancer therapies. Single-cell profiling also reveals drug-induced cellular phenotypic dynamics, unravelling previously unnoticed intra-tumour response diversity. The comprehensive view of the landscapes of cellular phenotypic heterogeneity in PDTXs uncovered by the BCMC panel, which is mirrored in primary human tumours, has profound implications for understanding and predicting therapy response and resistance.
We present the multiwavelength properties and catalogue of the 15μm and 1.4GHz radio sources detected in the European Large Area ISO Survey (ELAIS) areas N1 and N2. Using the optical data from the ...Wide Field Survey we use a likelihood ratio method to search for the counterparts of the 1056 and 691 sources detected at 15μm and 1.4GHz, respectively, down to flux limits of S15= 0.5mJy and S1.4GHz= 0.135mJy. We find that ∼92 per cent of the 15μm ELAIS sources have an optical counterpart down to r′= 24. All mid-infrared (IR) sources with fluxes S15≥ 3mJy have an optical counterpart. The magnitude distribution of the sources shows a well-defined peak at relatively bright magnitudes r′∼ 18. The mid-IR-to-optical and radio-to-optical flux diagrams are presented and discussed in terms of actual galaxy models. About 15 per cent of the sources are bright galactic stars; of the extragalactic objects ∼65 per cent are compatible with being normal or starburst galaxies and ∼25 per cent active galactic nuclei (AGNs). Objects with mid-IR-to-optical fluxes larger than 100 are found, comprising ∼20 per cent of the sample. We suggest that that these sources are highly obscured luminous and ultraluminous starburst galaxies and AGNs.
This paper describes 'PathGrid'-an analysis and data integration system, developed initially to meet the demands in the analysis of medical microscopy imaging data. An overview of the current system ...is given, describing the techniques used in developing the data handling infrastructure and the analysis algorithm development. The use of software created in the context of systems designed for the astronomy domain is noted, specifically infrastructure from the astronomy virtual observatory movement for data discovery, access and workflow management, and astronomical image analysis software adapted for the analysis of high-throughput astronomy imaging surveys. This paper notes the applicability of the techniques from the astronomy domain. The testbed infrastructure deployment is described, emphasizing its speed and ease of use and support. The validity of the analysis techniques is confirmed through the pilot study described here-with the application to a large sample of immunohistochemistry microscopy data obtained in part for assessing the oestrogen receptor status of breast cancers. The analysis showed that the specificity and sensitivity values for the automatic scoring using PathGrid were within the errors of those obtained via a 'gold standard' manual pathologist scoring.
Mid-infrared sources in the ELAIS Deep X-ray Survey Manners, J. C.; Serjeant, S.; Bottinelli, S. ...
Monthly notices of the Royal Astronomical Society,
November 2004, Letnik:
355, Številka:
1
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
We present a cross‐correlation of the European Large Area Infrared Space Observatory (ISO) survey (ELAIS) with the ELAIS Deep X‐ray Survey of the N1 and N2 fields. There are seven Chandra ...point sources with matches in the ELAIS Final Analysis 15‐μm catalogue, out of a total of 28 extragalactic ISO sources present in the Chandra fields. Five of these are consistent with active galactic nuclei (AGN) giving an AGN fraction of ∼19 per cent in the 15‐μm flux range 0.8–6 mJy. We have co‐added the hard X‐ray fluxes of the individually undetected ISO sources and find a low significance detection consistent with star formation in the remaining population. We combine our point source cross‐correlation fraction with the XMM–Newton observations of the Lockman Hole and Chandra observations of the Hubble Deep Field North to constrain source count models of the mid‐infrared galaxy population. The low dust‐enshrouded AGN fraction in ELAIS implied by the number of cross‐identifications between the ELAIS mid‐infrared sample and the Chandra point sources is encouraging for the use of mid‐infrared surveys to constrain the cosmic star formation history, provided there are not further large undetected populations of Compton‐thick AGN.
We present the first results of a survey for high-redshift, z ≥ 6, quasars using izY multicolour photometric observations from the Dark Energy Survey (DES). Here we report the discovery and ...spectroscopic confirmation of the z
AB, Y
AB = 20.2, 20.2 (M
1450 = −26.5) quasar DES J0454−4448 with a redshift of z = 6.09±0.02 based on the onset of the Ly α forest and an H i near zone size of 4.1
$_{-1.2}^{+1.1}$
proper Mpc. The quasar was selected as an i-band drop out with i−z = 2.46 and z
AB < 21.5 from an area of ∼300 deg2. It is the brightest of our 43 candidates and was identified for spectroscopic follow-up solely based on the DES i−z and z−Y colours. The quasar is detected by WISE and has W1AB = 19.68. The discovery of one spectroscopically confirmed quasar with 5.7 < z < 6.5 and z
AB ≤ 20.2 is consistent with recent determinations of the luminosity function at z ∼ 6. DES when completed will have imaged ∼5000 deg2 to Y
AB = 23.0 (5σ point source) and we expect to discover 50–100 new quasars with z > 6 including 3–10 with z > 7 dramatically increasing the numbers of quasars currently known that are suitable for detailed studies.
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 0.5–100mJy flux range and over an area of 10.85deg2 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.
SWIRE: The SIRTF Wide‐Area Infrared Extragalactic Survey Lonsdale, Carol J.; Smith, Harding E.; Rowan‐Robinson, Michael ...
Publications of the Astronomical Society of the Pacific,
08/2003, Letnik:
115, Številka:
810
Journal Article
ABSTRACT
This paper discusses the properties of the European Large Area ISO Survey (ELAIS) 15‐μm quasars and tries to establish a robust method of quasar selection for future use within the Spitzer ...Wide‐Area Infrared Extragalactic Survey (SWIRE) framework. The importance of good‐quality ground‐based optical data is stressed, both for the selection of candidates and for the estimation of photometric redshifts. Colour–colour plots and template fitting are used for these purposes. The properties of the 15‐μm quasar sample, including variability and black hole masses, are studied and compared to the properties of other quasars that lie within the same fields but have no mid‐infrared counterparts. The two subsamples do not present substantial differences and are believed to come from the same parent population.
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