54 research outputs found
Herschel Survey of the Palomar-Green QSOs at Low Redshift
We investigate the global cold dust properties of 85 nearby (z < 0.5) QSOs,
chosen from the Palomar-Green sample of optically luminous quasars. We
determine their infrared spectral energy distributions and estimate their
rest-frame luminosities by combining Herschel data from 70 to 500 microns with
near-infrared and mid-infrared measurements from the Two Micron All Sky Survey
(2MASS) and the Wide-Field Infrared Survey Explorer (WISE). In most sources the
far-infrared (FIR) emission can be attributed to thermally heated dust. Single
temperature modified black body fits to the FIR photometry give an average dust
temperature for the sample of 33~K, with a standard deviation of 8~K, and an
average dust mass of 7E6 Solar Masses with a standard deviation of 9E6 Solar
Masses. Estimates of star-formation that are based on the FIR continuum
emission correlate with those based on the 11.3 microns PAH feature, however,
the star-formation rates estimated from the FIR continuum are higher than those
estimated from the 11.3 microns PAH emission. We attribute this result to a
variety of factors including the possible destruction of the PAHs and that, in
some sources, a fraction of the FIR originates from dust heated by the active
galactic nucleus and by old stars.Comment: accepted for publication in ApJ
Maunakea Spectroscopic Explorer Advancing from Conceptual Design
The Maunakea Spectroscopic Explorer (MSE) project has completed its
Conceptual Design Phase. This paper is a status report of the MSE project
regarding its technical and programmatic progress. The technical status
includes its conceptual design and system performance, and highlights findings
and recommendations from the System and various subsystems design reviews. The
programmatic status includes the project organization and management plan for
the Preliminary Design Phase. In addition, this paper provides the latest
information related to the permitting process for Maunakea construction.Comment: 15 pages; Proceedings of SPIE Astronomical Telescopes +
Instrumentation 2018; Ground-based and Airborne Telescopes VI
The science calibration challenges of next generation highly multiplexed optical spectroscopy: the case of the Maunakea Spectroscopic Explorer
MSE is an 11.25m telescope with a 1.5 sq.deg. field of view. It can
simultaneously obtain 3249 spectra at R=3000 from 360-1800nm, and 1083 spectra
at R=40000 in the optical. The large field of view, large number of targets, as
well as the use of more than 4000 optical fibres to transport the light from
the focal plane to the spectrographs, means that precise and accurate science
calibration is difficult but essential to obtaining the science goals. As a
large aperture telescope focusing on the faint Universe, precision sky
subtraction and spectrophotometry are especially important. Here, we discuss
the science calibration requirements, and the adopted calibration strategy,
including operational features and hardware, that will enable the successful
scientific exploitation of the vast MSE dataset.Comment: Proceedings of SPIE Astronomical Telescopes + Instrumentation 2018;
Observatory Operations: Strategies, Processes, and Systems VI
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