393 research outputs found
Newly Discovered RR Lyrae Stars in the SDSSXPanXSTARRS1XCatalina Footprint
We present the detection of 6,371 RR Lyrae (RRL) stars distributed across
~14,000 deg^2 of the sky from the combined data of the Sloan Digital Sky Survey
(SDSS), the Panoramic Survey Telescope and Rapid Response System 1 (PS1), and
the second photometric catalogue from the Catalina Survey (CSDR2), out of
these, ~2,021 RRL stars (~572 RRab and 1,449 RRc) are new discoveries. The RRL
stars have heliocentric distances in the 4--28 kpc distance range. RRL-like
color cuts from the SDSS and variability cuts from the PS1 are used to cull our
candidate list. We then use the CSDR2 multi-epoch data to refine our sample.
Periods were measured using the Analysis of Variance technique while the
classification process is performed with the Template Fitting Method in
addition to the visual inspection of the light curves. A cross-match of our RRL
star discoveries with previous published catalogs of RRL stars yield
completeness levels of ~50% for both RRab and RRc stars, and an efficiency of
~99% and ~87% for RRab and RRc stars, respectively. We show that our method for
selecting RRL stars allows us to recover halo structures. The full lists of all
the RRL stars are made publicly available.Comment: 14 pages, 11 figures. Accepted 2014 March 30. Received 2014 March 12;
in original form 2013 November 2
The Ursa Major Cluster of Galaxies; 1, Cluster Definition and Photometric Data
The Ursa Major Cluster has received remarkably little attention, although it is as near as the Virgo Cluster and contains a comparable number of HI-rich galaxies. In this paper, criteria for group membership are discussed and data are presented for 79 galaxies identified with the group. Of these, all 79 have been imaged at B,R,I bands with CCDs, 70 have been imaged at K' with a HgCdTe array detector, and 70 have been detected in the HI 21cm line. A complete sample of 62 galaxies brighter than M(B)=-16.5 is identified. Images and gradients in surface brightness and color are presented at a common linear scale. As has been seen previously, the galaxies with the reddest global colors are reddest at the centers and get bluer at large radii. However, curiously, among the galaxies with the bluest global colors there are systems with very blue cores that get redder at large radii
Genomic imbalances are confined to non-proliferating cells in paediatric patients with acute myeloid leukaemia and a normal or incomplete karyotype
Copyright @ 2011 Ballabio et al.Leukaemia is often associated with genetic alterations such as translocations, amplifications and deletions, and recurrent chromosome abnormalities are used as markers of diagnostic and prognostic relevance. However, a proportion of acute myeloid leukaemia (AML) cases have an apparently normal karyotype despite comprehensive cytogenetic analysis. Based on conventional cytogenetic analysis of banded chromosomes, we selected a series of 23 paediatric patients with acute myeloid leukaemia and performed whole genome array comparative genome hybridization (aCGH) using DNA samples derived from the same patients. Imbalances involving large chromosomal regions or entire chromosomes were detected by aCGH in seven of the patients studied. Results were validated by fluorescence in situ hybridization (FISH) to both interphase nuclei and metaphase chromosomes using appropriate bacterial artificial chromosome (BAC) probes. The majority of these copy number alterations (CNAs) were confirmed by FISH and found to localize to the interphase rather than metaphase nuclei. Furthermore, the proliferative states of the cells analyzed by FISH were tested by immunofluorescence using an antibody against the proliferation marker pKi67. Interestingly, these experiments showed that, in the vast majority of cases, the changes appeared to be confined to interphase nuclei in a non-proliferative status.This work was supported by a grant from Leukaemia Research UK (grant no. 0253). SJLK and RR were supported by the NIHR Biomedical Research
Centre, Oxford, with funding from the Department of Health’s NIHR Biomedical Research Centres funding schemeThis article is available through the Brunel Open Access Publishing Fund
The Pan-STARRS1 Photometric System
The Pan-STARRS1 survey is collecting multi-epoch, multi-color observations of
the sky north of declination -30 deg to unprecedented depths. These data are
being photometrically and astrometrically calibrated and will serve as a
reference for many other purposes. In this paper we present our determination
of the Pan-STARRS photometric system: gp1, rp1, ip1, zp1, yp1, and wp1. The
Pan-STARRS photometric system is fundamentally based on the HST Calspec
spectrophotometric observations, which in turn are fundamentally based on
models of white dwarf atmospheres. We define the Pan-STARRS magnitude system,
and describe in detail our measurement of the system passbands, including both
the instrumental sensitivity and atmospheric transmission functions.
Byproducts, including transformations to other photometric systems, galactic
extinction, and stellar locus are also provided. We close with a discussion of
remaining systematic errors.Comment: 39 pages, 9 figures, machine readable table of bandpasses, accepted
for publication in Ap
The Ursa Major Cluster of Galaxies. I. Cluster Definition and Photometric Data
The Ursa Major Cluster has received remarkably little attention, although it
is as near as the Virgo Cluster and contains a comparable number of HI-rich
galaxies. In this paper, criteria for group membership are discussed and data
are presented for 79 galaxies identified with the group. Of these, all 79 have
been imaged at B,R,I bands with CCDs, 70 have been imaged at K' with a HgCdTe
array detector, and 70 have been detected in the HI 21cm line. A complete
sample of 62 galaxies brighter than M(B)=-16.5 is identified. Images and
gradients in surface brightness and color are presented at a common linear
scale. As has been seen previously, the galaxies with the reddest global colors
are reddest at the centers and get bluer at large radii. However, curiously,
among the galaxies with the bluest global colors there are systems with very
blue cores that get redder at large radii.Comment: A LATEX file without figures. The postscript version (7.1Mb in
gzipped format) including all the tables, figures and scanned versions of the
plates can be retrieved as preprint no.208 from
http://www.astro.rug.nl:80/~secr/ Accepted for publication in The
Astronomical Journa
- …