Clustering in Deep (Submillimeter) Surveys

Hughes & Gaztanaga (2001, see article in these proceedings) have presented realistic simulations to address key issues confronting existing and forthcoming submm surveys. An important aspect illustrated by the simulations is the effect induced on the counts by the sampling variance of the large-scale galaxy clustering. We find factors of up to 2-4 variation (from the mean) in the extracted counts from deep surveys identical in area (6 sqr arcmin) to the SCUBA surveys of the Hubble Deep Fields (HDF). Here we present a recipe to model the expected degree of clustering as a function of sample area and redshift.Comment: 5 pages, 1 figure, UMass/INAOE conference proceedings on `Deep millimeter surveys', eds. J. Lowenthal and D. Hughes, World Scientifi

Optical off-nuclear spectra of quasar hosts and radio galaxies

We present optical (~3200A to ~9000A) off-nuclear spectra of 26 powerful active galaxies in the redshift range 0.1 < z < 0.3, obtained with the Mayall and William Herschel 4-meter class telescopes. The sample consists of radio-quiet quasars, radio-loud quasars (all with -23 > M_V > -26) and radio galaxies of Fanaroff & Riley Type II (with extended radio luminosities and spectral indices comparable to those of the radio-loud quasars). The spectra were all taken approximately 5 arcseconds off-nucleus, with offsets carefully selected so as to maximise the amount of galaxy light falling into the slit, whilst simultaneously minimising the amount of scattered nuclear light. The majority of the resulting spectra appear to be dominated by the integrated stellar continuum of the underlying galaxies rather than by light from the non-stellar processes occurring in the active nuclei, and in many cases a 4000A break feature can be identified. The individual spectra are described in detail, and the importance of the various spectral components is discussed. Stellar population synthesis modelling of the spectra will follow in a subsequent paper (Nolan et al. 2000).Comment: 23 pages, LaTeX, uses MNRAS style file, incorporates 71 postscript figures, to be published in MNRAS. Contact author: [email protected]

The ages of quasar host galaxies

We present the results of fitting deep off-nuclear optical spectroscopy of radio-quiet quasars, radio-loud quasars and radio galaxies at z ~ 0.2 with evolutionary synthesis models of galaxy evolution. Our aim was to determine the age of the dynamically dominant stellar populations in the hos t galaxies of these three classes of powerful AGN. Some of our spectra display residual nuclear contamination at the shortest wavelengths, but the detailed quality of the fits longward of the 4000A break provide unequivocal proof, if further proof were needed, that quasars lie in massive galaxies with (at least at z ~ 0.2) evolved stellar populations. By fitting a two-component model we have separated the very blue (starburst and/or AGN contamination) from the redder underlying spectral energy distribution, and find that the hosts of all three classes of AGN are dominated by old stars of age 8 - 14 Gyr. If the blue component is attributed to young stars, we find that, at most, 1% of the baryonic mass of these galaxies is involved in star-formation activity at the epoch of observation. These results strongly support the conclusion reached by McLure et al. (1999) that the host galaxies of luminous quasars are massive ellipticals which formed prior to the peak epoch of quasar activity at z ~ 2.5.Comment: 24 pages, LaTeX, uses MNRAS style file, incorporates 19 postscript figures, final version, to be published in MNRA

A new genus to accommodate \u3cem\u3eGymnopus acervatus\u3c/em\u3e (Agaricales)

Phylogenies based on ITS and LSU nrDNA sequences show Agaricus (Gymnopus) acervatus as unique within the Gymnopus/Rhodocollybia complex. These phylogenies imply that a separate genus is necessary, and Connopus is proposed. Infraspecific morphological and DNA-based variation within C. acervatus suggests that a western North American clade might be reproductively isolated from the eastern North American/Scandinavian clade and that in this species complex the European and eastern North American clade might be conspecific. A Scandinavian exemplar is selected for bar-coding. Two GenBank sequences with name-phylogenetic placement inconsistencies are identified

The Infrared Properties of Submillimeter Galaxies: Clues From Ultra-Deep 70 Micron Imaging

We present 70 micron properties of submillimeter galaxies (SMGs) in the Great Observatories Origins Deep Survey (GOODS) North field. Out of thirty submillimeter galaxies (S_850 > 2 mJy) in the central GOODS-N region, we find two with secure 70 micron detections. These are the first 70 micron detections of SMGs. One of the matched SMGs is at z ~ 0.5 and has S_70/S_850 and S_70/S_24 ratios consistent with a cool galaxy. The second SMG (z = 1.2) has infrared-submm colors which indicate it is more actively forming stars. We examine the average 70 micron properties of the SMGs by performing a stacking analysis, which also allows us to estimate that S_850 > 2 mJy SMGs contribute 9 +- 3% of the 70 micron background light. The S_850/S_70 colors of the SMG population as a whole is best fit by cool galaxies, and because of the redshifting effects these constraints are mainly on the lower z sub-sample. We fit Spectral Energy Distributions (SEDs) to the far-infrared data points of the two detected SMGs and the average low redshift SMG (z_{median}= 1.4). We find that the average low-z SMG has a cooler dust temperature than local ultraluminous infrared galaxies (ULIRGs) of similar luminosity and an SED which is best fit by scaled up versions of normal spiral galaxies. The average low-z SMG is found to have a typical dust temperature T = 21 -- 33 K and infrared luminosity L_{8-1000 micron} = 8.0 \times 10^11 L_sun. We estimate the AGN contribution to the total infrared luminosity of low-z SMGs is less than 23%.Comment: Accepted by ApJ. 14 pages, 6 figures. Minor revisions 20th Dec 200

Incidence, outcomes, and risk factors of pleural effusion in patients receiving dasatinib therapy for Philadelphia chromosome-positive leukemia.

Dasatinib, a second-generation BCR-ABL1 tyrosine kinase inhibitor, is approved for the treatment of chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia, both as first-line therapy and after imatinib intolerance or resistance. While generally well tolerated, dasatinib has been associated with a higher risk for pleural effusions. Frequency, risk factors, and outcomes associated with pleural effusion were assessed in two phase 3 trials (DASISION and 034/Dose-optimization) and a pooled population of 11 trials that evaluated patients with chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia treated with dasatinib (including DASISION and 034/Dose-optimization). In this largest assessment of patients across the dasatinib clinical trial program (N=2712), pleural effusion developed in 6-9% of patients at risk annually in DASISION, and in 5-15% of patients at risk annually in 034/Dose-optimization. With a minimum follow up of 5 and 7 years, drug-related pleural effusion occurred in 28% of patients in DASISION and in 33% of patients in 034/Dose-optimization, respectively. A significant risk factor identified for developing pleural effusion by a multivariate analysis was age. We found that overall responses to dasatinib, progression-free survival, and overall survival were similar in patients who developed pleural effusion and in patients who did not. clinicaltrials.gov identifier 00481247; 00123474

Constraints on the Accuracy of Photometric Redshifts Derived from BLAST and Herschel/SPIRE Sub-mm Surveys

More than 150 galaxies have been detected in blank-field millimetre and sub-millimetre surveys. However the redshift distribution of sub-mm galaxies remains uncertain due to the difficulty in identifying their optical-IR counterparts, and subsequently obtaining their spectroscopic emission-line redshifts. In this paper we discuss results from a Monte-Carlo analysis of the accuracy with which one can determine redshifts from photometric measurements at sub-millimetre-FIR wavelengths. The analysis takes into account the dispersion in colours introduced by including galaxies with a distribution of SEDs, and by including photometric and absolute calibration errors associated with real observations. We present examples of the probability distribution of redshifts for individual galaxies detected in the future BLAST and Herschel/SPIRE surveys. We show that the combination of BLAST and 850um observations constrain the photometric redshifts with sufficient accuracy to pursue a program of spectroscopic follow-up with the 100m GBT.Comment: 3 pages, 5 figures, in 2K1BC symposium "Experimental Cosmology at Millimetre Wavelengths", ed. M. de Petris and M. Gervasi, AIP, in pres

Confirmation of the effectiveness of sub-mm source redshift estimation based on rest-frame radio to FIR photometry

We present a comparison between the published optical, IR and CO spectroscopic redshifts of 15 (sub-)mm galaxies and their photometric redshifts as derived from long-wavelength (radio-mm-FIR) photometric data. The redshift accuracy measured for 12 sub-mm galaxies with at least one robustly-determined colour in the radio-mm-FIR regime is dz=0.30 (r.m.s.). Despite the wide range of spectral energy distributions in the local galaxies that are used in an un-biased manner as templates, this analysis demonstrates that photometric redshifts can be efficiently derived for sub-mm galaxies with a precision of dz < 0.5 using only the rest-frame FIR to radio wavelength data.Comment: submitted to MNRAS (1 object removed from analysis, shortening of paper