547 research outputs found
Buerger's disease manifesting nodular erythema with livedo reticularis
ArticleINTERNAL MEDICINE. 46(21):1815-1819(2007)journal articl
Development of a High Pumping Speed Cryosorption Pump for Neutral Beam Injector in JIPP T-IIU Tokamak
Subaru FOCAS Spectroscopic Observations of High-Redshift Supernovae
We present spectra of high-redshift supernovae (SNe) that were taken with the
Subaru low resolution optical spectrograph, FOCAS. These SNe were found in SN
surveys with Suprime-Cam on Subaru, the CFH12k camera on the
Canada-France-Hawaii Telescope (CFHT), and the Advanced Camera for Surveys
(ACS) on the Hubble Space Telescope (HST). These SN surveys specifically
targeted z>1 Type Ia supernovae (SNe Ia). From the spectra of 39 candidates, we
obtain redshifts for 32 candidates and spectroscopically identify 7 active
candidates as probable SNe Ia, including one at z=1.35, which is the most
distant SN Ia to be spectroscopically confirmed with a ground-based telescope.
An additional 4 candidates are identified as likely SNe Ia from the
spectrophotometric properties of their host galaxies. Seven candidates are not
SNe Ia, either being SNe of another type or active galactic nuclei. When SNe Ia
are observed within a week of maximum light, we find that we can
spectroscopically identify most of them up to z=1.1. Beyond this redshift, very
few candidates were spectroscopically identified as SNe Ia. The current
generation of super red-sensitive, fringe-free CCDs will push this redshift
limit higher.Comment: 19 pages, 26 figures. PASJ in press. see
http://www.supernova.lbl.gov/2009ClusterSurvey/ for additional information
pertaining to the HST Cluster SN Surve
The Hubble Space Telescope Cluster Supernova Survey: VI. The Volumetric Type Ia Supernova Rate
We present a measurement of the volumetric Type Ia supernova (SN Ia) rate out
to z ~ 1.6 from the Hubble Space Telescope Cluster Supernova Survey. In
observations spanning 189 orbits with the Advanced Camera for Surveys we
discovered 29 SNe, of which approximately 20 are SNe Ia. Twelve of these SNe Ia
are located in the foregrounds and backgrounds of the clusters targeted in the
survey. Using these new data, we derive the volumetric SN Ia rate in four broad
redshift bins, finding results consistent with previous measurements at z > 1
and strengthening the case for a SN Ia rate that is equal to or greater than
~0.6 x 10^-4/yr/Mpc^3 at z ~ 1 and flattening out at higher redshift. We
provide SN candidates and efficiency calculations in a form that makes it easy
to rebin and combine these results with other measurements for increased
statistics. Finally, we compare the assumptions about host-galaxy dust
extinction used in different high-redshift rate measurements, finding that
different assumptions may induce significant systematic differences between
measurements.Comment: 11 pages, 7 figures. Submitted to the Astrophysical Journal. Revised
version following referee comments. See the HST Cluster SN Survey website at
http://supernova.lbl.gov/2009ClusterSurvey for control time simulations in a
machine-readable table and a complete listing of transient candidates from
the surve
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